flatland_client_lib/

game.rs

use std::collections::{BTreeMap, VecDeque};
use std::time::{Duration, Instant};

use flatland_protocol::{
    AbilityCooldownHud, BlueprintView, BodySlot, BuildingView, CastProgressHud, CombatHud,
    CombatSlotHud, CombatTargetHud, DoorView, EntityId, EntityState, Intent, InteriorMapView,
    LifeState, NpcView, RotationPreset, Seq, SessionId, TerrainKindView, TerrainZoneView, Tick,
    ZPlatformView, ZTransitionView,
};

use crate::session::{PlayConnection, SessionEvent};

/// Matches `flatland_sim::containers` prop keys (client does not depend on sim).
const KEY_TEMPLATE: &str = "container_key";
const PROP_LOCK_ID: &str = "lock_id";
const PROP_OPENS_LOCK_ID: &str = "opens_lock_id";
const PROP_OPENS_CONTAINER_NAME: &str = "opens_container_name";
const PROP_CUSTOM_NAME: &str = "custom_name";
const PROP_LOCKED: &str = "locked";

fn stack_is_locked(stack: &flatland_protocol::ItemStack) -> bool {
    stack
        .props
        .get(PROP_LOCKED)
        .is_some_and(|v| v == "true" || v == "1")
}

const MAX_LOG_LINES: usize = 200;
const MAX_SHOP_TRADE_LOG_LINES: usize = 40;
const INTERACTION_RADIUS_M: f32 = 1.5;
const DOOR_INTERACTION_RADIUS_M: f32 = 3.5;
const QUEST_BOARD_INTERACTION_RADIUS_M: f32 = 3.0;
const HARVEST_CLIENT_TIMEOUT: Duration = Duration::from_secs(12);
/// Matches `assets/config/server-settings.yaml` default for batch-cap UI estimates.
const CRAFT_STAMINA_COST: f32 = 3.0;

/// Catalog hints synced from server `ItemStack` wire rows.
#[derive(Debug, Clone, Default)]
pub struct InventoryHint {
    pub display_name: String,
    pub category: String,
    pub base_mass: Option<f32>,
    pub base_volume: Option<f32>,
    pub capacity_volume: Option<f32>,
    pub stackable: bool,
}

/// Rotation editor overlay mode (`plans/26` §C2.5).
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum RotationEditorMode {
    #[default]
    List,
    EditSequence,
    PickAbility,
    EditLabel,
}

/// Local rotation editor UI state (not persisted).
#[derive(Debug, Clone, Default)]
pub struct RotationEditorState {
    pub mode: RotationEditorMode,
    pub list_index: usize,
    pub ability_index: usize,
    pub picker_index: usize,
    pub draft: Option<RotationPreset>,
    pub label_buffer: String,
}

impl RotationEditorState {
    pub fn reset(&mut self) {
        *self = Self::default();
    }
}

/// Max distance (m) a placed chest can be browsed/moved-into from the inventory
/// UI. Mirrors `flatland_sim::interaction::CONTAINER_INTERACTION_RADIUS_M` so the
/// client only ever shows chests the server will actually let you use — this is
/// what makes a chest disappear from the menu as soon as you walk away.
pub const CONTAINER_RANGE_M: f32 = 3.0;

/// Broad section of the inventory browser a row belongs to (drives the grouped
/// "Worn" / "On you" / "Nearby chest" headers in the UI).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum InventorySection {
    /// Inside a worn body-slot item (backpack, belt w/ clipped pouches, armor).
    Worn,
    /// Loose on your person — not worn, not inside a placed chest.
    Person,
    /// Inside a placed chest within reach.
    Nearby,
}

/// Short display label for a body slot (`plans/08` §4.1) — shared by the inventory
/// browser section headers and the move-destination picker.
pub fn body_slot_label(slot: BodySlot) -> &'static str {
    match slot {
        BodySlot::Head => "Head",
        BodySlot::Body => "Body",
        BodySlot::Arms => "Arms",
        BodySlot::Legs => "Legs",
        BodySlot::Feet => "Feet",
        BodySlot::Back => "Back",
        BodySlot::Waist => "Waist",
    }
}

/// Client-side naming heuristic for "Enter equips this" — the client doesn't sync the
/// item catalog's `equip_slot`, so this guesses from `template_id` the same way the
/// pre-generalization code already guessed backpack vs. pouch. Pouches deliberately
/// aren't covered — they attach to belt loops via the move picker instead of equipping
/// directly (`plans/08` §4.1).
fn guess_body_slot(template_id: &str) -> Option<BodySlot> {
    if template_id.contains("backpack") {
        Some(BodySlot::Back)
    } else if template_id.contains("belt") {
        Some(BodySlot::Waist)
    } else if template_id.contains("cap")
        || template_id.contains("hat")
        || template_id.contains("helm")
    {
        Some(BodySlot::Head)
    } else if template_id.contains("shirt")
        || template_id.contains("robe")
        || template_id.contains("vest")
    {
        Some(BodySlot::Body)
    } else if template_id.contains("sleeves")
        || template_id.contains("gloves")
        || template_id.contains("gauntlets")
    {
        Some(BodySlot::Arms)
    } else if template_id.contains("pants") || template_id.contains("leggings") {
        Some(BodySlot::Legs)
    } else if template_id.contains("boots") || template_id.contains("shoes") {
        Some(BodySlot::Feet)
    } else {
        None
    }
}

/// One row in the inventory browser tree.
#[derive(Debug, Clone)]
pub struct InventoryRow {
    pub depth: usize,
    pub stack: flatland_protocol::ItemStack,
    /// `MoveItem` source location for this stack.
    pub from: flatland_protocol::InventoryLocation,
    /// Parent container instance when nested (belt shell, backpack, chest, pouch).
    pub from_parent_instance_id: Option<uuid::Uuid>,
    /// Equipped bag/chest shell — unequip via Enter instead of the move picker.
    pub is_equip_shell: bool,
    /// Placed world chest shell — lock/unlock via Enter or `l`.
    pub is_chest_shell: bool,
    pub section: InventorySection,
}

/// Formatted inventory row text shared by TUI and gfx browsers.
#[derive(Debug, Clone)]
pub struct InventoryRowView {
    pub depth: usize,
    pub text: String,
}

/// One line in the sectioned inventory browser (headers are non-selectable).
#[derive(Debug, Clone)]
pub enum InventoryBrowserLine {
    Section(String),
    SlotLabel(String),
    Hint(String),
    Blank,
    Item {
        selectable_index: usize,
        selected: bool,
        depth: usize,
        text: String,
    },
}

/// A placed chest within `CONTAINER_RANGE_M`, with its contents pre-flattened for
/// the browser (empty when locked without the matching key).
#[derive(Debug, Clone)]
pub struct NearbyContainer {
    pub view: flatland_protocol::PlacedContainerView,
    pub distance_m: f32,
    pub rows: Vec<InventoryRow>,
}

/// One key row in the keychain overlay (carried vs stowed).
#[derive(Debug, Clone)]
pub struct KeychainEntry {
    pub stack: flatland_protocol::ItemStack,
    pub stowed: bool,
}

/// A destination the currently-picked item could be moved to.
#[derive(Debug, Clone)]
pub struct MoveOption {
    pub label: String,
    pub kind: MoveOptionKind,
}

#[derive(Debug, Clone, PartialEq)]
pub enum MoveOptionKind {
    Move {
        location: flatland_protocol::InventoryLocation,
        parent_instance_id: Option<uuid::Uuid>,
    },
    Drop,
    Cancel,
}

/// Active "move to…" destination picker state for the selected inventory item.
#[derive(Debug, Clone)]
pub struct MovePicker {
    pub item_instance_id: uuid::Uuid,
    pub from: flatland_protocol::InventoryLocation,
    pub item_label: String,
    pub template_id: String,
    pub stack_quantity: u32,
    pub quantity: u32,
    pub options: Vec<MoveOption>,
}

/// Active permanent-delete picker for the selected inventory item.
#[derive(Debug, Clone)]
pub struct DestroyPicker {
    pub item_instance_id: uuid::Uuid,
    pub from: flatland_protocol::InventoryLocation,
    pub item_label: String,
    pub stack_quantity: u32,
    pub quantity: u32,
}

fn push_inventory_rows(
    rows: &mut Vec<InventoryRow>,
    depth: usize,
    stack: &flatland_protocol::ItemStack,
    from: &flatland_protocol::InventoryLocation,
    from_parent_instance_id: Option<uuid::Uuid>,
    section: InventorySection,
) {
    rows.push(InventoryRow {
        depth,
        stack: stack.clone(),
        from: from.clone(),
        from_parent_instance_id,
        is_equip_shell: false,
        is_chest_shell: false,
        section,
    });
    for child in &stack.contents {
        push_inventory_rows(
            rows,
            depth + 1,
            child,
            from,
            stack.item_instance_id,
            section,
        );
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum ShopTab {
    #[default]
    Buy,
    Sell,
}

#[derive(Debug, Clone, Default)]
pub struct NpcChatState {
    pub npc_id: String,
    pub npc_label: String,
    pub lines: Vec<String>,
    pub input: String,
    pub pending: bool,
}

#[derive(Debug, Clone)]
pub struct GameState {
    pub session_id: SessionId,
    pub entity_id: EntityId,
    /// Logged-in character — used to show owner-only container labels.
    pub character_id: Option<uuid::Uuid>,
    pub tick: Tick,
    pub chunk_rev: u64,
    pub content_rev: u64,
    pub entities: Vec<EntityState>,
    pub player: Option<EntityState>,
    pub resource_nodes: Vec<flatland_protocol::ResourceNodeView>,
    pub ground_drops: Vec<flatland_protocol::GroundDropView>,
    pub placed_containers: Vec<flatland_protocol::PlacedContainerView>,
    pub buildings: Vec<BuildingView>,
    pub doors: Vec<DoorView>,
    pub interior_map: Option<InteriorMapView>,
    pub npcs: Vec<NpcView>,
    pub blueprints: Vec<BlueprintView>,
    pub world_width_m: f32,
    pub world_height_m: f32,
    pub terrain_zones: Vec<TerrainZoneView>,
    pub z_platforms: Vec<ZPlatformView>,
    pub z_transitions: Vec<ZTransitionView>,
    pub world_clock: flatland_protocol::WorldClock,
    pub inventory: std::collections::HashMap<String, u32>,
    pub inventory_hints: std::collections::HashMap<String, InventoryHint>,
    pub logs: VecDeque<String>,
    pub intents_sent: u64,
    pub ticks_received: u64,
    pub connected: bool,
    pub disconnect_reason: Option<String>,
    pub show_stats: bool,
    pub show_craft_menu: bool,
    pub craft_menu_index: usize,
    /// How many timed crafts to queue when confirming the craft menu.
    pub craft_batch_quantity: u32,
    pub show_shop_menu: bool,
    pub shop_catalog: Option<flatland_protocol::ShopCatalog>,
    pub shop_tab: ShopTab,
    pub shop_menu_index: usize,
    pub shop_quantity: u32,
    /// Recent buy/sell lines while the shop panel is open (gfx dock).
    pub shop_trade_log: VecDeque<String>,
    pub show_npc_verb_menu: bool,
    pub npc_verb_target: Option<String>,
    pub npc_verb_index: usize,
    pub show_npc_chat: bool,
    pub npc_chat: Option<NpcChatState>,
    pub show_inventory_menu: bool,
    pub inventory_menu_index: usize,
    pub show_move_picker: bool,
    pub move_picker_index: usize,
    pub move_picker: Option<MovePicker>,
    pub show_destroy_picker: bool,
    pub destroy_confirm_pending: bool,
    pub destroy_picker: Option<DestroyPicker>,
    /// Rename prompt for a selected container (`n` in inventory).
    pub show_rename_prompt: bool,
    pub rename_buffer: String,
    /// Slot-1 combat target (mirrors server after SetTarget).
    pub combat_target: Option<EntityId>,
    pub combat_target_label: Option<String>,
    pub in_combat: bool,
    pub auto_attack: bool,
    pub combat_has_los: bool,
    pub attack_cd_ticks: u64,
    pub gcd_ticks: u64,
    pub weapon_ability_id: String,
    pub mainhand_template_id: Option<String>,
    pub mainhand_label: Option<String>,
    /// Worn body-slot items — backpack (`Back`), belt w/ clipped pouches (`Waist`), and
    /// future armor. At most one item per slot (`plans/08` §4.1).
    pub worn: BTreeMap<BodySlot, flatland_protocol::ItemStack>,
    pub carry_mass: f32,
    pub carry_mass_max: f32,
    pub encumbrance: flatland_protocol::EncumbranceState,
    /// Full nested inventory stacks from the server (root only; worn are separate).
    pub inventory_stacks: Vec<flatland_protocol::ItemStack>,
    /// Keys stowed on the virtual keychain (zero carry mass).
    pub keychain_stacks: Vec<flatland_protocol::ItemStack>,
    pub combat_target_detail: Option<CombatTargetHud>,
    pub cast_progress: Option<CastProgressHud>,
    pub ability_cooldowns: Vec<AbilityCooldownHud>,
    pub blocking_active: bool,
    pub max_target_slots: u8,
    pub combat_slots: Vec<CombatSlotHud>,
    pub rotation_presets: Vec<RotationPreset>,
    pub show_loadout_menu: bool,
    pub show_keychain_menu: bool,
    pub keychain_menu_index: usize,
    pub show_rotation_editor: bool,
    pub loadout_menu_index: usize,
    pub rotation_editor: RotationEditorState,
    /// True after a harvest intent is accepted until result/reject/disconnect.
    pub harvest_in_progress: bool,
    /// Wall-clock start of the current harvest; clears stale client state on timeout.
    pub harvest_started_at: Option<Instant>,
    /// Craft log deferred until the server acks the craft intent.
    pub pending_craft_ack: Option<(u32, String, u32)>,
    pub quest_log: Vec<flatland_protocol::QuestLogEntry>,
    pub interactables: Vec<flatland_protocol::InteractableView>,
    pub show_quest_offer: bool,
    pub pending_quest_offer: Option<flatland_protocol::QuestOffer>,
    pub show_quest_menu: bool,
    pub quest_menu_index: usize,
    pub quest_withdraw_confirm: bool,
    /// Server progression curve from the latest combat HUD (matches server-settings.yaml).
    pub progression_curve: Option<flatland_protocol::ProgressionCurve>,
}

impl GameState {
    pub fn push_log(&mut self, line: impl Into<String>) {
        self.logs.push_back(line.into());
        while self.logs.len() > MAX_LOG_LINES {
            self.logs.pop_front();
        }
    }

    pub fn push_shop_trade_log(&mut self, line: impl Into<String>) {
        self.shop_trade_log.push_back(line.into());
        while self.shop_trade_log.len() > MAX_SHOP_TRADE_LOG_LINES {
            self.shop_trade_log.pop_front();
        }
    }

    pub fn clear_shop_trade_log(&mut self) {
        self.shop_trade_log.clear();
    }

    fn record_shop_trade_notice(&mut self, notice: &flatland_protocol::InteractionNotice) {
        if !self.show_shop_menu {
            return;
        }
        let msg = notice.message.trim();
        if msg.is_empty() {
            return;
        }
        if notice.coins_delta != 0
            || msg.starts_with("Bought ")
            || msg.starts_with("Sold ")
            || msg.contains("taught you how to craft")
            || msg.starts_with("need ")
        {
            self.push_shop_trade_log(msg);
        }
    }

    pub fn is_alive(&self) -> bool {
        self.player
            .as_ref()
            .and_then(|p| p.vitals)
            .map(|v| v.life_state == LifeState::Alive && v.health > 0.0)
            .unwrap_or(true)
    }

    /// Verb menu entries for the current `npc_verb_target` (Talk, and Trade when applicable).
    pub fn npc_verb_options(&self) -> Vec<&'static str> {
        let Some(ref id) = self.npc_verb_target else {
            return vec![];
        };
        let Some(npc) = self.npcs.iter().find(|n| &n.id == id) else {
            return vec!["Talk"];
        };
        if npc.can_trade || Self::npc_role_can_trade(npc.role.as_str()) {
            vec!["Talk", "Trade"]
        } else {
            vec!["Talk"]
        }
    }

    fn npc_role_can_trade(role: &str) -> bool {
        matches!(role, "broker" | "cook" | "farmer" | "merchant")
    }

    pub fn clear_harvest_state(&mut self) {
        self.harvest_in_progress = false;
        self.harvest_started_at = None;
    }

    fn harvest_state_stale(&self) -> bool {
        match self.harvest_started_at {
            Some(started) => started.elapsed() > HARVEST_CLIENT_TIMEOUT,
            None => self.harvest_in_progress,
        }
    }

    pub fn vitals(&self) -> Option<flatland_protocol::PlayerVitals> {
        self.player.as_ref().and_then(|p| p.vitals)
    }

    pub fn can_craft_blueprint(&self, blueprint: &BlueprintView) -> bool {
        let materials_ok = blueprint.inputs.iter().all(|input| {
            self.inventory.get(&input.template_id).copied().unwrap_or(0) >= input.quantity
        });
        let tools_ok = blueprint
            .required_tools
            .iter()
            .all(|tool| self.inventory.get(&tool.item).copied().unwrap_or(0) >= 1);
        let station_ok = match blueprint.station.as_deref() {
            None | Some("hand") => true,
            Some(tag) => self.player_at_station_tag(tag),
        };
        materials_ok && tools_ok && station_ok
    }

    pub fn max_craft_batches(&self, blueprint: &BlueprintView) -> u32 {
        if !self.can_craft_blueprint(blueprint) {
            return 0;
        }
        let mut limit = u32::MAX;
        for input in &blueprint.inputs {
            if input.quantity == 0 {
                continue;
            }
            let have = self.inventory.get(&input.template_id).copied().unwrap_or(0);
            limit = limit.min(have / input.quantity);
        }
        for tool in &blueprint.required_tools {
            if tool.consumed {
                let have = self.inventory.get(&tool.item).copied().unwrap_or(0);
                limit = limit.min(have);
            }
        }
        let stamina = self.vitals().map(|v| v.stamina).unwrap_or(0.0);
        if CRAFT_STAMINA_COST > 0.0 {
            limit = limit.min((stamina / CRAFT_STAMINA_COST).floor() as u32);
        }
        limit
    }

    pub fn clamp_craft_batch_quantity(&mut self) {
        let Some(bp) = self.blueprints.get(self.craft_menu_index) else {
            self.craft_batch_quantity = 1;
            return;
        };
        let max = self.max_craft_batches(bp).max(1);
        self.craft_batch_quantity = self.craft_batch_quantity.clamp(1, max);
    }

    pub fn craft_batch_adjust_quantity(&mut self, delta: i32) {
        let Some(bp) = self.blueprints.get(self.craft_menu_index).cloned() else {
            return;
        };
        let max = self.max_craft_batches(&bp).max(1);
        let next = (self.craft_batch_quantity as i32 + delta).clamp(1, max as i32);
        self.craft_batch_quantity = next as u32;
    }

    pub fn craft_batch_set_max(&mut self) {
        let Some(bp) = self.blueprints.get(self.craft_menu_index).cloned() else {
            return;
        };
        let max = self.max_craft_batches(&bp);
        self.craft_batch_quantity = if max == 0 { 1 } else { max };
    }

    pub fn apply_shop_catalog(&mut self, catalog: flatland_protocol::ShopCatalog) {
        let preserve_ui = self.show_shop_menu;
        let tab = self.shop_tab;
        let index = self.shop_menu_index;
        let qty = self.shop_quantity;

        self.show_shop_menu = true;
        self.show_craft_menu = false;
        self.show_inventory_menu = false;
        self.show_stats = false;
        self.shop_catalog = Some(catalog);

        if preserve_ui {
            self.shop_tab = tab;
            self.shop_menu_index = index;
            self.shop_quantity = qty;
        } else {
            self.shop_tab = ShopTab::Buy;
            self.shop_menu_index = 0;
            self.shop_quantity = 1;
            self.clear_shop_trade_log();
        }
        self.clamp_shop_selection();
    }

    pub fn shop_list_len(&self) -> usize {
        let Some(catalog) = &self.shop_catalog else {
            return 0;
        };
        match self.shop_tab {
            ShopTab::Buy => catalog.sells.len(),
            ShopTab::Sell => catalog.buys.len(),
        }
    }

    pub fn shop_menu_move(&mut self, delta: i32) {
        let n = self.shop_list_len();
        if n == 0 {
            return;
        }
        let idx = self.shop_menu_index as i32;
        let next = (idx + delta).rem_euclid(n as i32);
        self.shop_menu_index = next as usize;
        self.clamp_shop_quantity();
    }

    pub fn shop_quantity_adjust(&mut self, delta: i32) {
        let max = self.shop_quantity_max();
        let next = (self.shop_quantity as i32 + delta).clamp(1, max as i32);
        self.shop_quantity = next as u32;
    }

    pub(crate) fn clamp_shop_selection(&mut self) {
        let n = self.shop_list_len();
        if n == 0 {
            self.shop_menu_index = 0;
        } else {
            self.shop_menu_index = self.shop_menu_index.min(n - 1);
        }
        self.clamp_shop_quantity();
    }

    fn shop_quantity_max(&self) -> u32 {
        let Some(catalog) = &self.shop_catalog else {
            return 1;
        };
        match self.shop_tab {
            ShopTab::Buy => {
                if let Some(offer) = catalog.sells.get(self.shop_menu_index) {
                    if offer.kind == flatland_protocol::ShopOfferKind::Blueprint {
                        return 1;
                    }
                }
                99
            }
            ShopTab::Sell => catalog
                .buys
                .get(self.shop_menu_index)
                .map(|l| l.quantity)
                .unwrap_or(1)
                .max(1),
        }
    }

    pub fn shop_quantity_set_max(&mut self) {
        self.shop_quantity = self.shop_quantity_max();
    }

    fn clamp_shop_quantity(&mut self) {
        self.shop_quantity = self.shop_quantity.clamp(1, self.shop_quantity_max());
    }

    pub fn player_at_station_tag(&self, tag: &str) -> bool {
        let Some(id) = self.effective_inside_building() else {
            return false;
        };
        self.buildings
            .iter()
            .find(|b| b.id == id)
            .is_some_and(|b| b.tags.iter().any(|t| t == tag))
    }

    /// Short hint for UI when a recipe cannot be started.
    pub fn craft_missing_hint(&self, blueprint: &BlueprintView) -> Option<String> {
        if self.can_craft_blueprint(blueprint) {
            return None;
        }
        let mut missing = Vec::new();
        for input in &blueprint.inputs {
            let have = self.inventory.get(&input.template_id).copied().unwrap_or(0);
            if have < input.quantity {
                missing.push(format!(
                    "{}×{} (have {have})",
                    input.quantity, input.template_id
                ));
            }
        }
        for tool in &blueprint.required_tools {
            let have = self.inventory.get(&tool.item).copied().unwrap_or(0);
            if have < 1 {
                missing.push(format!("tool: {}", tool.item));
            }
        }
        if let Some(station) = blueprint.station.as_deref() {
            if station != "hand" && !self.player_at_station_tag(station) {
                missing.push(format!("station: {station} (enter building)"));
            }
        }
        if missing.is_empty() {
            None
        } else {
            Some(missing.join(", "))
        }
    }

    pub fn player_entity(&self) -> Option<&EntityState> {
        self.player
            .as_ref()
            .or_else(|| self.entities.iter().find(|e| e.id == self.entity_id))
    }

    pub fn player_position(&self) -> (f32, f32) {
        let (x, y, _) = self.player_position_with_z();
        (x, y)
    }

    pub fn player_position_with_z(&self) -> (f32, f32, f32) {
        if let Some(p) = self.player_entity() {
            (
                p.transform.position.x,
                p.transform.position.y,
                p.transform.position.z,
            )
        } else {
            (0.0, 0.0, 0.0)
        }
    }

    pub fn sorted_inventory(&self) -> Vec<(String, u32, String)> {
        let mut rows: Vec<(String, u32, String)> = self
            .inventory
            .iter()
            .filter(|(_, q)| **q > 0)
            .map(|(id, qty)| {
                let label = self
                    .inventory_hints
                    .get(id)
                    .map(|h| h.display_name.clone())
                    .unwrap_or_else(|| id.clone());
                (id.clone(), *qty, label)
            })
            .collect();
        rows.sort_by(|a, b| a.2.cmp(&b.2).then_with(|| a.0.cmp(&b.0)));
        rows
    }

    pub fn inventory_item_category(&self, template_id: &str) -> Option<&str> {
        self.inventory_hints
            .get(template_id)
            .map(|h| h.category.as_str())
            .filter(|c| !c.is_empty())
    }

    pub fn item_base_mass(&self, template_id: &str) -> f32 {
        self.inventory_hints
            .get(template_id)
            .and_then(|h| h.base_mass)
            .unwrap_or(0.5)
    }

    pub fn item_base_volume(&self, template_id: &str) -> f32 {
        self.inventory_hints
            .get(template_id)
            .and_then(|h| h.base_volume)
            .unwrap_or(1.0)
    }

    pub fn stack_mass(&self, stack: &flatland_protocol::ItemStack) -> f32 {
        let unit = stack
            .base_mass
            .unwrap_or_else(|| self.item_base_mass(&stack.template_id));
        unit * stack.quantity as f32
    }

    fn stack_tree_volume(stack: &flatland_protocol::ItemStack) -> f32 {
        let unit = stack.base_volume.unwrap_or(1.0);
        unit * stack.quantity as f32
            + stack
                .contents
                .iter()
                .map(Self::stack_tree_volume)
                .sum::<f32>()
    }

    fn contents_used_volume(contents: &[flatland_protocol::ItemStack]) -> f32 {
        contents.iter().map(Self::stack_tree_volume).sum()
    }

    fn template_capacity_volume(&self, template_id: &str) -> Option<f32> {
        self.inventory_hints
            .get(template_id)
            .and_then(|h| h.capacity_volume)
            .filter(|c| *c > 0.0)
    }

    fn stack_capacity_volume(&self, stack: &flatland_protocol::ItemStack) -> Option<f32> {
        stack
            .capacity_volume
            .filter(|c| *c > 0.0)
            .or_else(|| self.template_capacity_volume(&stack.template_id))
    }

    /// Volume used / capacity / free space label for storage containers in the inventory UI.
    pub fn container_volume_label(&self, row: &InventoryRow) -> String {
        let Some((used, cap)) = self.container_volume_stats(row) else {
            return String::new();
        };
        let free = (cap - used).max(0.0);
        format!("  vol {used:.0}/{cap:.0} ({free:.0} free)")
    }

    fn container_volume_stats(&self, row: &InventoryRow) -> Option<(f32, f32)> {
        if row.is_chest_shell {
            let flatland_protocol::InventoryLocation::Placed { container_id } = &row.from else {
                return None;
            };
            let chest = self
                .placed_containers
                .iter()
                .find(|c| c.id == *container_id)?;
            let cap = self
                .stack_capacity_volume(&row.stack)
                .or(chest.capacity_volume.filter(|c| *c > 0.0))?;
            let used = if chest.accessible {
                Self::contents_used_volume(&chest.contents)
            } else {
                0.0
            };
            return Some((used, cap));
        }

        let cap = self.stack_capacity_volume(&row.stack)?;
        let used = Self::contents_used_volume(&row.stack.contents);
        Some((used, cap))
    }

    pub fn row_is_renameable_container(&self, row: &InventoryRow) -> bool {
        if row.is_chest_shell {
            return true;
        }
        if row.is_equip_shell {
            return self.inventory_item_category(&row.stack.template_id) == Some("container");
        }
        self.inventory_item_category(&row.stack.template_id) == Some("container")
            || row.stack.capacity_volume.is_some_and(|c| c > 0.0)
    }

    fn container_stack_for(
        &self,
        location: &flatland_protocol::InventoryLocation,
        parent_instance_id: Option<uuid::Uuid>,
    ) -> Option<flatland_protocol::ItemStack> {
        match location {
            flatland_protocol::InventoryLocation::Root => {
                let pid = parent_instance_id?;
                self.find_stack_by_instance(&self.inventory_stacks, pid)
            }
            flatland_protocol::InventoryLocation::Worn { slot } => {
                let worn = self.worn.get(slot)?;
                if parent_instance_id.is_none_or(|id| worn.item_instance_id == Some(id)) {
                    Some(worn.clone())
                } else {
                    self.find_stack_by_instance(&worn.contents, parent_instance_id?)
                }
            }
            flatland_protocol::InventoryLocation::Placed { container_id } => {
                let chest = self
                    .placed_containers
                    .iter()
                    .find(|c| c.id == *container_id)?;
                if parent_instance_id.is_none_or(|id| chest.item_instance_id == Some(id)) {
                    Some(flatland_protocol::ItemStack {
                        template_id: chest.template_id.clone(),
                        quantity: 1,
                        item_instance_id: chest.item_instance_id,
                        props: Default::default(),
                        contents: chest.contents.clone(),
                        display_name: Some(chest.display_name.clone()),
                        category: Some("container".into()),
                        base_mass: None,
                        base_volume: None,
                        capacity_volume: self
                            .inventory_hints
                            .get(&chest.template_id)
                            .and_then(|h| h.capacity_volume),
                        stackable: None,
                    })
                } else {
                    self.find_stack_by_instance(&chest.contents, parent_instance_id?)
                }
            }
            flatland_protocol::InventoryLocation::Keychain => None,
        }
    }

    fn find_stack_by_instance(
        &self,
        stacks: &[flatland_protocol::ItemStack],
        instance_id: uuid::Uuid,
    ) -> Option<flatland_protocol::ItemStack> {
        for stack in stacks {
            if stack.item_instance_id == Some(instance_id) {
                return Some(stack.clone());
            }
            if let Some(found) = self.find_stack_by_instance(&stack.contents, instance_id) {
                return Some(found);
            }
        }
        None
    }

    /// Client-side estimate of how many units can move to `to` (server clamps authoritatively).
    pub fn max_movable_to(
        &self,
        template_id: &str,
        stack_qty: u32,
        from: &flatland_protocol::InventoryLocation,
        to: &flatland_protocol::InventoryLocation,
        parent_instance_id: Option<uuid::Uuid>,
    ) -> u32 {
        let unit_vol = self.item_base_volume(template_id);
        let unit_mass = self.item_base_mass(template_id);
        let mut limit = stack_qty;

        if let Some(parent) = self.container_stack_for(to, parent_instance_id) {
            let cap = parent
                .capacity_volume
                .or_else(|| {
                    self.inventory_hints
                        .get(&parent.template_id)
                        .and_then(|h| h.capacity_volume)
                })
                .unwrap_or(0.0);
            if cap > 0.0 && unit_vol > 0.0 {
                let remaining = (cap - Self::contents_used_volume(&parent.contents)).max(0.0);
                limit = limit.min((remaining / unit_vol).floor().max(0.0) as u32);
            }
        }

        let to_person = matches!(
            to,
            flatland_protocol::InventoryLocation::Root
                | flatland_protocol::InventoryLocation::Worn { .. }
        );
        let from_placed = matches!(from, flatland_protocol::InventoryLocation::Placed { .. });
        if to_person && from_placed && unit_mass > 0.0 {
            let headroom = (self.carry_mass_max - self.carry_mass).max(0.0);
            if self.encumbrance == flatland_protocol::EncumbranceState::Over {
                limit = 0;
            } else {
                limit = limit.min((headroom / unit_mass).floor().max(0.0) as u32);
            }
        }

        limit.max(0).min(stack_qty)
    }

    pub fn move_picker_max_at_selection(&self) -> u32 {
        let Some(picker) = &self.move_picker else {
            return 1;
        };
        let Some(opt) = picker.options.get(self.move_picker_index) else {
            return picker.stack_quantity;
        };
        match &opt.kind {
            MoveOptionKind::Cancel | MoveOptionKind::Drop => picker.stack_quantity,
            MoveOptionKind::Move {
                location,
                parent_instance_id,
            } => self.max_movable_to(
                &picker.template_id,
                picker.stack_quantity,
                &picker.from,
                location,
                *parent_instance_id,
            ),
        }
    }

    pub fn clamp_move_picker_quantity(&mut self) {
        let max = self.move_picker_max_at_selection();
        if let Some(picker) = &mut self.move_picker {
            if max == 0 {
                picker.quantity = 1;
            } else {
                picker.quantity = picker.quantity.clamp(1, max);
            }
        }
    }

    pub fn move_picker_adjust_quantity(&mut self, delta: i32) {
        let max = self.move_picker_max_at_selection().max(1);
        if let Some(picker) = &mut self.move_picker {
            let next = (picker.quantity as i32 + delta).clamp(1, max as i32);
            picker.quantity = next as u32;
        }
    }

    pub fn move_picker_set_quantity_max(&mut self) {
        let max = self.move_picker_max_at_selection();
        if let Some(picker) = &mut self.move_picker {
            picker.quantity = if max == 0 {
                1
            } else {
                max.min(picker.stack_quantity)
            };
        }
    }

    pub fn destroy_picker_adjust_quantity(&mut self, delta: i32) {
        if let Some(picker) = &mut self.destroy_picker {
            let max = picker.stack_quantity.max(1);
            let next = (picker.quantity as i32 + delta).clamp(1, max as i32);
            picker.quantity = next as u32;
        }
    }

    pub fn destroy_picker_set_quantity_max(&mut self) {
        if let Some(picker) = &mut self.destroy_picker {
            picker.quantity = picker.stack_quantity.max(1);
        }
    }

    pub fn ingredient_status(&self, template_id: &str, need: u32) -> (u32, bool) {
        let have = self.inventory.get(template_id).copied().unwrap_or(0);
        (have, have >= need)
    }

    pub fn currency_display(&self) -> String {
        crate::currency::currency_line(&self.inventory)
    }

    /// True when standing in a shallow-water terrain zone from the segment snapshot.
    pub fn in_shallow_water(&self) -> bool {
        let (px, py) = self.player_position();
        self.terrain_at(px, py)
            .is_some_and(|k| k == TerrainKindView::ShallowWater)
    }

    pub fn terrain_at(&self, x: f32, y: f32) -> Option<TerrainKindView> {
        self.terrain_zone_at(x, y).map(|z| z.kind)
    }

    /// First terrain zone containing `(x, y)` in segment YAML order.
    pub fn terrain_zone_at(&self, x: f32, y: f32) -> Option<&TerrainZoneView> {
        self.terrain_zones
            .iter()
            .find(|z| x >= z.x0 && x <= z.x1 && y >= z.y0 && y <= z.y1)
    }

    /// Ground elevation from terrain zones (m).
    pub fn elevation_at(&self, x: f32, y: f32) -> f32 {
        self.terrain_zone_at(x, y)
            .map(|z| z.elevation)
            .unwrap_or(0.0)
    }

    /// Walkable z levels at a map column (terrain + platforms).
    pub fn walkable_levels_at(&self, x: f32, y: f32) -> Vec<f32> {
        const TOL: f32 = 0.35;
        let mut levels = vec![self.elevation_at(x, y)];
        for p in &self.z_platforms {
            if x >= p.x0 && x <= p.x1 && y >= p.y0 && y <= p.y1 {
                levels.push(p.z);
            }
        }
        levels.sort_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal));
        levels.dedup_by(|a, b| (*a - *b).abs() < TOL);
        levels
    }

    pub fn is_walkable_at_z(&self, x: f32, y: f32, z: f32) -> bool {
        const TOL: f32 = 0.35;
        self.walkable_levels_at(x, y)
            .iter()
            .any(|&l| (l - z).abs() <= TOL)
    }

    pub fn surface_elevation_at(&self, x: f32, y: f32) -> f32 {
        let mut top = self.elevation_at(x, y);
        for p in &self.z_platforms {
            if x >= p.x0 && x <= p.x1 && y >= p.y0 && y <= p.y1 {
                top = top.max(p.z);
            }
        }
        top
    }

    /// Authoritative interior context from the server (`inside_building` flag).
    pub fn effective_inside_building(&self) -> Option<String> {
        self.player_entity().and_then(|p| p.inside_building.clone())
    }

    pub fn sync_inventory_from_stacks(&mut self, stacks: &[flatland_protocol::ItemStack]) {
        self.inventory_stacks = stacks.to_vec();
        self.inventory.clear();
        self.inventory_hints.clear();
        fn walk(
            stacks: &[flatland_protocol::ItemStack],
            inventory: &mut std::collections::HashMap<String, u32>,
            hints: &mut std::collections::HashMap<String, InventoryHint>,
        ) {
            for stack in stacks {
                *inventory.entry(stack.template_id.clone()).or_insert(0) += stack.quantity;
                if stack.display_name.is_some()
                    || stack.category.is_some()
                    || stack.base_mass.is_some()
                    || stack.base_volume.is_some()
                {
                    hints.insert(
                        stack.template_id.clone(),
                        InventoryHint {
                            display_name: stack
                                .display_name
                                .clone()
                                .unwrap_or_else(|| stack.template_id.clone()),
                            category: stack.category.clone().unwrap_or_default(),
                            base_mass: stack.base_mass,
                            base_volume: stack.base_volume,
                            capacity_volume: stack.capacity_volume,
                            stackable: stack.stackable.unwrap_or(true),
                        },
                    );
                }
                walk(&stack.contents, inventory, hints);
            }
        }
        walk(stacks, &mut self.inventory, &mut self.inventory_hints);
        // Include worn items (and nested contents, e.g. belt-clipped pouches) in craft counts.
        for item in self.worn.values() {
            walk(
                std::slice::from_ref(item),
                &mut self.inventory,
                &mut self.inventory_hints,
            );
        }
    }

    /// Apply server interaction deltas immediately (quest rewards, shop, etc.) so the
    /// inventory UI updates before the next tick snapshot arrives.
    pub fn apply_interaction_notice(&mut self, notice: &flatland_protocol::InteractionNotice) {
        let subtract_items =
            notice.message.starts_with("Sold ") || notice.message.starts_with("Consumed ");
        for stack in &notice.inventory_delta {
            if stack.quantity == 0 {
                continue;
            }
            if subtract_items {
                crate::currency::drain_template_stacks(
                    &mut self.inventory_stacks,
                    &stack.template_id,
                    stack.quantity,
                );
                continue;
            }
            let stackable = self
                .inventory_hints
                .get(&stack.template_id)
                .map(|h| h.stackable)
                .or(stack.stackable)
                .unwrap_or(true);
            if stackable {
                if let Some(existing) = self
                    .inventory_stacks
                    .iter_mut()
                    .find(|s| s.template_id == stack.template_id)
                {
                    existing.quantity = existing.quantity.saturating_add(stack.quantity);
                    if stack.display_name.is_some() {
                        existing.display_name = stack.display_name.clone();
                    }
                    if stack.category.is_some() {
                        existing.category = stack.category.clone();
                    }
                    continue;
                }
            }
            self.inventory_stacks.push(stack.clone());
        }
        if notice.coins_delta != 0 {
            crate::currency::apply_coins_delta(&mut self.inventory_stacks, notice.coins_delta);
        }
        if !notice.inventory_delta.is_empty() || notice.coins_delta != 0 {
            let stacks = self.inventory_stacks.clone();
            self.sync_inventory_from_stacks(&stacks);
        }
        self.record_shop_trade_notice(notice);
    }

    /// Worn body-slot items — each shown as a shell row (unequip via Enter) followed by
    /// its nested contents (e.g. pouches clipped onto a worn belt). `BodySlot` derives
    /// `Ord` in display order (Head/Body/Arms/Legs/Feet/Back/Waist), so `BTreeMap`
    /// iteration alone gives a stable row order.
    pub fn worn_rows(&self) -> Vec<InventoryRow> {
        let mut rows = Vec::new();
        for (slot, item) in &self.worn {
            let from = flatland_protocol::InventoryLocation::Worn { slot: *slot };
            rows.push(InventoryRow {
                depth: 0,
                stack: item.clone(),
                from: from.clone(),
                from_parent_instance_id: None,
                is_equip_shell: true,
                is_chest_shell: false,
                section: InventorySection::Worn,
            });
            for child in &item.contents {
                push_inventory_rows(
                    &mut rows,
                    1,
                    child,
                    &from,
                    item.item_instance_id,
                    InventorySection::Worn,
                );
            }
        }
        rows
    }

    /// Loose on-person inventory (not worn, not inside a placed chest).
    pub fn person_rows(&self) -> Vec<InventoryRow> {
        let mut rows = Vec::new();
        for stack in &self.inventory_stacks {
            push_inventory_rows(
                &mut rows,
                0,
                stack,
                &flatland_protocol::InventoryLocation::Root,
                None,
                InventorySection::Person,
            );
        }
        rows
    }

    /// Legacy alias used by the HUD sidebar summary (worn + on-person, unchanged).
    pub fn inventory_tree_rows(&self) -> Vec<(usize, flatland_protocol::ItemStack)> {
        let mut rows = self.worn_rows();
        rows.extend(self.person_rows());
        rows.into_iter().map(|r| (r.depth, r.stack)).collect()
    }

    /// Placed chests within `CONTAINER_RANGE_M`, nearest first. Contents are only
    /// populated when `accessible` — this is what makes a chest's contents
    /// disappear the moment you walk away or it's locked without your key.
    pub fn nearby_containers(&self) -> Vec<NearbyContainer> {
        let (px, py) = self.player_position();
        let mut list: Vec<NearbyContainer> = self
            .placed_containers
            .iter()
            .filter_map(|c| {
                let distance_m = (c.x - px).hypot(c.y - py);
                if distance_m > CONTAINER_RANGE_M {
                    return None;
                }
                let mut rows = Vec::new();
                let from = flatland_protocol::InventoryLocation::Placed {
                    container_id: c.id.clone(),
                };
                rows.push(InventoryRow {
                    depth: 0,
                    stack: flatland_protocol::ItemStack {
                        template_id: c.template_id.clone(),
                        quantity: 1,
                        item_instance_id: c.item_instance_id,
                        props: Default::default(),
                        contents: Vec::new(),
                        display_name: Some(c.display_name.clone()),
                        category: Some("container".into()),
                        base_mass: None,
                        base_volume: None,
                        capacity_volume: c.capacity_volume,
                        stackable: None,
                    },
                    from: from.clone(),
                    from_parent_instance_id: None,
                    is_equip_shell: false,
                    is_chest_shell: true,
                    section: InventorySection::Nearby,
                });
                if c.accessible {
                    for child in &c.contents {
                        push_inventory_rows(
                            &mut rows,
                            1,
                            child,
                            &from,
                            c.item_instance_id,
                            InventorySection::Nearby,
                        );
                    }
                }
                Some(NearbyContainer {
                    view: c.clone(),
                    distance_m,
                    rows,
                })
            })
            .collect();
        list.sort_by(|a, b| {
            a.distance_m
                .partial_cmp(&b.distance_m)
                .unwrap_or(std::cmp::Ordering::Equal)
        });
        list
    }

    /// Nearest placed chest within `max_dist`, regardless of accessibility.
    pub fn nearest_placed_container(
        &self,
        max_dist: f32,
    ) -> Option<flatland_protocol::PlacedContainerView> {
        let (px, py) = self.player_position();
        self.placed_containers
            .iter()
            .filter(|c| (c.x - px).hypot(c.y - py) <= max_dist)
            .min_by(|a, b| {
                let da = (a.x - px).hypot(a.y - py);
                let db = (b.x - px).hypot(b.y - py);
                da.partial_cmp(&db).unwrap_or(std::cmp::Ordering::Equal)
            })
            .cloned()
    }

    /// Full ordered list of *selectable* rows: worn ++ on-person ++ each nearby
    /// accessible chest's contents (nearest chest first). This single order drives
    /// `inventory_menu_index`; the renderer must build its grouped headers by
    /// walking `worn_rows()` / `person_rows()` / `nearby_containers()` in the same
    /// sequence so the highlighted row always matches.
    pub fn inventory_selectable_rows(&self) -> Vec<InventoryRow> {
        let mut rows = self.worn_rows();
        rows.extend(self.person_rows());
        for nc in self.nearby_containers() {
            rows.extend(nc.rows);
        }
        rows
    }

    pub fn inventory_selected_row(&self) -> Option<InventoryRow> {
        self.inventory_selectable_rows()
            .into_iter()
            .nth(self.inventory_menu_index)
    }

    /// Format one selectable inventory row for TUI/gfx (label + hints + mass/volume).
    pub fn format_inventory_row(&self, row: &InventoryRow) -> InventoryRowView {
        let cat = self
            .inventory_item_category(&row.stack.template_id)
            .unwrap_or("");
        let label = if cat == "key" {
            self.key_inventory_label(&row.stack)
        } else {
            row.stack
                .display_name
                .clone()
                .unwrap_or_else(|| row.stack.template_id.clone())
        };
        let hint: String = if row.is_equip_shell {
            " [worn — Enter to unequip]".into()
        } else if row.is_chest_shell {
            let locked = match &row.from {
                flatland_protocol::InventoryLocation::Placed { container_id } => self
                    .placed_containers
                    .iter()
                    .find(|c| c.id == *container_id)
                    .map(|c| c.locked)
                    .unwrap_or(false),
                _ => false,
            };
            if locked {
                " [locked — Enter/l to unlock]".into()
            } else {
                " [Enter/l to lock]".into()
            }
        } else if cat == "key" {
            self.key_inventory_hint(&row.stack)
        } else {
            match cat {
                "weapon" => " [weapon]".into(),
                "container" => " [bag/chest/belt]".into(),
                "armor" => " [armor]".into(),
                _ => String::new(),
            }
        };
        let qty = if row.stack.quantity > 1 {
            format!(" ×{}", row.stack.quantity)
        } else {
            String::new()
        };
        let mass = self.stack_mass(&row.stack);
        let mass_str = if mass >= 0.05 {
            format!("  {:.1} kg", mass)
        } else {
            String::new()
        };
        let vol_str = self.container_volume_label(row);
        InventoryRowView {
            depth: row.depth,
            text: format!("{label}{hint}{qty}{mass_str}{vol_str}"),
        }
    }

    /// Sectioned inventory browser lines for gfx/TUI. Selectable rows carry
    /// `selectable_index` matching `inventory_menu_index`.
    pub fn inventory_browser_lines(&self) -> Vec<InventoryBrowserLine> {
        let mut lines = Vec::new();
        let target = self.inventory_menu_index;
        let highlight = !self.show_move_picker;
        let mut global_idx = 0usize;

        lines.push(InventoryBrowserLine::Section("— Worn —".into()));
        let worn = self.worn_rows();
        if worn.is_empty() {
            lines.push(InventoryBrowserLine::Hint(
                "  (nothing equipped — wear a backpack/belt from \"On you\" below)".into(),
            ));
        } else {
            for row in &worn {
                if row.is_equip_shell {
                    if let flatland_protocol::InventoryLocation::Worn { slot } = row.from {
                        lines.push(InventoryBrowserLine::SlotLabel(format!(
                            "  {}:",
                            body_slot_label(slot)
                        )));
                    }
                }
                let view = self.format_inventory_row(row);
                lines.push(InventoryBrowserLine::Item {
                    selectable_index: global_idx,
                    selected: highlight && global_idx == target,
                    depth: view.depth,
                    text: view.text,
                });
                global_idx += 1;
            }
        }

        lines.push(InventoryBrowserLine::Blank);
        lines.push(InventoryBrowserLine::Section(
            "— On you (loose, not worn) —".into(),
        ));
        let person = self.person_rows();
        if person.is_empty() {
            lines.push(InventoryBrowserLine::Hint("  (empty)".into()));
        } else {
            for row in &person {
                let view = self.format_inventory_row(row);
                lines.push(InventoryBrowserLine::Item {
                    selectable_index: global_idx,
                    selected: highlight && global_idx == target,
                    depth: view.depth,
                    text: view.text,
                });
                global_idx += 1;
            }
        }

        let nearby = self.nearby_containers();
        if nearby.is_empty() {
            lines.push(InventoryBrowserLine::Blank);
            lines.push(InventoryBrowserLine::Section("— Nearby chests —".into()));
            lines.push(InventoryBrowserLine::Hint(
                "  (none within reach — walk up to a chest)".into(),
            ));
        } else {
            for nc in &nearby {
                lines.push(InventoryBrowserLine::Blank);
                let lock_note = if nc.view.locked && nc.view.accessible {
                    "  unlocked with your key"
                } else if nc.view.locked {
                    "  locked"
                } else {
                    ""
                };
                lines.push(InventoryBrowserLine::Section(format!(
                    "— {} ({:.0}m away){lock_note} —",
                    nc.view.display_name, nc.distance_m
                )));
                if !nc.view.accessible {
                    lines.push(InventoryBrowserLine::Hint(
                        "  locked — need the matching key (l to try)".into(),
                    ));
                } else if nc.rows.is_empty() {
                    lines.push(InventoryBrowserLine::Hint(
                        "  (empty — select chest row above, m to move items in)".into(),
                    ));
                } else {
                    for row in &nc.rows {
                        let view = self.format_inventory_row(row);
                        lines.push(InventoryBrowserLine::Item {
                            selectable_index: global_idx,
                            selected: highlight && global_idx == target,
                            depth: view.depth,
                            text: view.text,
                        });
                        global_idx += 1;
                    }
                }
            }
        }
        lines
    }

    /// Build the "move to…" destination list for an item currently at `from`.
    pub fn move_destinations_for(
        &self,
        from: &flatland_protocol::InventoryLocation,
        from_parent_instance_id: Option<uuid::Uuid>,
        moving_instance_id: Option<uuid::Uuid>,
        moving_template_id: &str,
    ) -> Vec<MoveOption> {
        let mut opts = Vec::new();
        if *from != flatland_protocol::InventoryLocation::Root {
            opts.push(MoveOption {
                label: "On your person (loose)".into(),
                kind: MoveOptionKind::Move {
                    location: flatland_protocol::InventoryLocation::Root,
                    parent_instance_id: None,
                },
            });
        }
        for (slot, item) in &self.worn {
            if item.category.as_deref() != Some("container") {
                continue;
            }
            let location = flatland_protocol::InventoryLocation::Worn { slot: *slot };
            let shell_name = item
                .display_name
                .clone()
                .unwrap_or_else(|| item.template_id.clone());

            // Backpack and other worn volume containers — store directly inside the shell.
            if *slot != BodySlot::Waist
                && item.item_instance_id != moving_instance_id
                && Self::is_volume_container_stack(item)
            {
                Self::push_move_destination(
                    &mut opts,
                    format!("{shell_name} (worn {})", body_slot_label(*slot)),
                    location.clone(),
                    item.item_instance_id,
                    from,
                    from_parent_instance_id,
                );
            }

            // Belt loops only accept pouch attachments — not loose materials.
            if *slot == BodySlot::Waist
                && Self::attaches_to_belt_loop(moving_template_id)
                && item.item_instance_id != moving_instance_id
            {
                Self::push_move_destination(
                    &mut opts,
                    format!("{shell_name} (belt loop)"),
                    location.clone(),
                    item.item_instance_id,
                    from,
                    from_parent_instance_id,
                );
            }

            let context = if *slot == BodySlot::Waist {
                format!("on {shell_name}")
            } else {
                format!("in {shell_name}")
            };
            Self::append_nested_container_destinations(
                &mut opts,
                location,
                item,
                &context,
                from,
                from_parent_instance_id,
                moving_instance_id,
            );
        }
        for nc in self.nearby_containers() {
            if !nc.view.accessible {
                continue;
            }
            let location = flatland_protocol::InventoryLocation::Placed {
                container_id: nc.view.id.clone(),
            };
            Self::push_move_destination(
                &mut opts,
                format!("{} ({:.0}m away)", nc.view.display_name, nc.distance_m),
                location,
                nc.view.item_instance_id,
                from,
                from_parent_instance_id,
            );
        }
        let allow_drop = moving_instance_id
            .and_then(|id| self.stack_for_instance(id))
            .map(|stack| !self.key_drop_blocked(&stack))
            .unwrap_or(moving_template_id != KEY_TEMPLATE);
        if allow_drop {
            opts.push(MoveOption {
                label: "Drop on the ground".into(),
                kind: MoveOptionKind::Drop,
            });
        }
        opts.push(MoveOption {
            label: "Cancel".into(),
            kind: MoveOptionKind::Cancel,
        });
        opts
    }

    fn is_same_container_dest(
        dest_location: &flatland_protocol::InventoryLocation,
        dest_parent: Option<uuid::Uuid>,
        from: &flatland_protocol::InventoryLocation,
        from_parent: Option<uuid::Uuid>,
    ) -> bool {
        dest_location == from && dest_parent == from_parent
    }

    fn push_move_destination(
        opts: &mut Vec<MoveOption>,
        label: String,
        location: flatland_protocol::InventoryLocation,
        parent_instance_id: Option<uuid::Uuid>,
        from: &flatland_protocol::InventoryLocation,
        from_parent_instance_id: Option<uuid::Uuid>,
    ) {
        if Self::is_same_container_dest(
            &location,
            parent_instance_id,
            from,
            from_parent_instance_id,
        ) {
            return;
        }
        opts.push(MoveOption {
            label,
            kind: MoveOptionKind::Move {
                location,
                parent_instance_id,
            },
        });
    }

    fn is_volume_container_stack(stack: &flatland_protocol::ItemStack) -> bool {
        stack.capacity_volume.is_some_and(|c| c > 0.0)
    }

    fn attaches_to_belt_loop(template_id: &str) -> bool {
        matches!(template_id, "leather_pouch" | "dimensional_pouch")
    }

    fn append_nested_container_destinations(
        opts: &mut Vec<MoveOption>,
        location: flatland_protocol::InventoryLocation,
        container: &flatland_protocol::ItemStack,
        context: &str,
        from: &flatland_protocol::InventoryLocation,
        from_parent_instance_id: Option<uuid::Uuid>,
        moving_instance_id: Option<uuid::Uuid>,
    ) {
        for child in &container.contents {
            if Self::is_volume_container_stack(child)
                && child.item_instance_id != moving_instance_id
            {
                let name = child
                    .display_name
                    .clone()
                    .unwrap_or_else(|| child.template_id.clone());
                Self::push_move_destination(
                    opts,
                    format!("{name} ({context})"),
                    location.clone(),
                    child.item_instance_id,
                    from,
                    from_parent_instance_id,
                );
            }
            let nested_context = format!(
                "in {}",
                child.display_name.as_deref().unwrap_or(&child.template_id)
            );
            Self::append_nested_container_destinations(
                opts,
                location.clone(),
                child,
                &nested_context,
                from,
                from_parent_instance_id,
                moving_instance_id,
            );
        }
    }

    fn clamp_inventory_indices(&mut self) {
        let n = self.inventory_selectable_rows().len();
        self.inventory_menu_index = if n == 0 {
            0
        } else {
            self.inventory_menu_index.min(n - 1)
        };
        if let Some(picker) = &self.move_picker {
            let pn = picker.options.len();
            self.move_picker_index = if pn == 0 {
                0
            } else {
                self.move_picker_index.min(pn - 1)
            };
        }
    }

    /// Drop interior map layers whenever the player is outdoors.
    fn sync_interior_map_context(&mut self) {
        if self.effective_inside_building().is_none() {
            self.interior_map = None;
        }
    }

    fn apply_snapshot_fields(
        &mut self,
        snapshot: &flatland_protocol::Snapshot,
        entity_id: EntityId,
    ) {
        self.tick = snapshot.tick;
        self.chunk_rev = snapshot.chunk_rev;
        self.content_rev = snapshot.content_rev;
        self.resource_nodes = snapshot.resource_nodes.clone();
        self.ground_drops = snapshot.ground_drops.clone();
        self.placed_containers = snapshot.placed_containers.clone();
        self.world_width_m = snapshot.world_width_m;
        self.world_height_m = snapshot.world_height_m;
        self.world_clock = snapshot.world_clock;
        self.terrain_zones = snapshot.terrain_zones.clone();
        self.z_platforms = snapshot.z_platforms.clone();
        self.z_transitions = snapshot.z_transitions.clone();
        self.buildings = snapshot.buildings.clone();
        self.doors = snapshot.doors.clone();
        self.interior_map = snapshot.interior_map.clone();
        self.npcs = snapshot.npcs.clone();
        self.blueprints = snapshot.blueprints.clone();
        self.sync_inventory_from_stacks(&snapshot.inventory);
        self.player = snapshot
            .entities
            .iter()
            .find(|e| e.id == entity_id)
            .cloned();
        self.entities = snapshot.entities.clone();
        self.quest_log = snapshot.quest_log.clone();
        self.interactables = snapshot.interactables.clone();
        self.sync_interior_map_context();
    }

    /// Re-derive inventory selection state after a snapshot/tick — chests that
    /// went out of range or got locked simply vanish from the row list, and the
    /// move picker (if any) closes once its item is no longer reachable.
    fn refresh_inventory_ui(&mut self) {
        if let Some(picker) = &self.move_picker {
            let instance_id = picker.item_instance_id;
            let still_exists = self
                .inventory_selectable_rows()
                .iter()
                .any(|r| r.stack.item_instance_id == Some(instance_id));
            if !still_exists {
                self.move_picker = None;
                self.show_move_picker = false;
            }
        }
        if let Some(picker) = &self.destroy_picker {
            let instance_id = picker.item_instance_id;
            let still_exists = self
                .inventory_selectable_rows()
                .iter()
                .any(|r| r.stack.item_instance_id == Some(instance_id));
            if !still_exists {
                self.destroy_picker = None;
                self.show_destroy_picker = false;
                self.destroy_confirm_pending = false;
            }
        }
        self.clamp_inventory_indices();
    }

    fn apply_combat_hud(&mut self, combat: &CombatHud) {
        self.in_combat = combat.in_combat;
        self.auto_attack = combat.auto_attack;
        self.combat_has_los = combat.has_los;
        self.attack_cd_ticks = combat.attack_cd_ticks;
        self.gcd_ticks = combat.gcd_ticks;
        self.weapon_ability_id = combat.ability_id.clone();
        self.mainhand_template_id = combat.mainhand_template_id.clone();
        self.mainhand_label = combat.mainhand_label.clone();
        self.worn = combat.worn.iter().cloned().collect();
        self.carry_mass = combat.carry_mass;
        self.carry_mass_max = combat.carry_mass_max;
        self.encumbrance = combat.encumbrance;
        self.cast_progress = combat.cast.clone();
        self.ability_cooldowns = combat.ability_cooldowns.clone();
        self.blocking_active = combat.blocking_active;
        self.max_target_slots = combat.max_target_slots.max(1);
        self.combat_slots = combat.slots.clone();
        self.rotation_presets = combat.rotation_presets.clone();
        self.keychain_stacks = combat.keychain.clone();
        self.combat_target_detail = combat.target.clone();
        self.combat_target = combat.target_entity_id;
        if combat.progression_xp_base > 0.0 {
            self.progression_curve = Some(flatland_protocol::ProgressionCurve {
                baseline_display: combat.progression_baseline,
                xp_base: combat.progression_xp_base,
                xp_growth: combat.progression_xp_growth,
            });
        }
        if let Some(xp) = &combat.progression_xp {
            if let Some(player) = &mut self.player {
                player.progression_xp = Some(xp.clone());
                if let Some(attrs) = combat.attributes {
                    player.attributes = Some(attrs);
                }
                if let Some(skills) = &combat.skills {
                    player.skills = Some(skills.clone());
                }
            }
        }
        if let Some(label) = &combat.target_label {
            self.combat_target_label = Some(label.clone());
        } else if let Some(id) = combat.target_entity_id {
            self.combat_target_label = self
                .entities
                .iter()
                .find(|e| e.id == id)
                .map(|e| e.label.clone())
                .or_else(|| self.combat_target_label.clone());
        }
        self.refresh_inventory_ui();
    }

    /// Entity id assigned to a combat slot (from server HUD).
    pub fn target_for_slot(&self, slot: u8) -> Option<EntityId> {
        self.combat_slots
            .iter()
            .find(|s| s.slot_index == slot)
            .and_then(|s| s.target_entity_id)
            .or_else(|| if slot == 1 { self.combat_target } else { None })
    }

    /// Hostile wildlife / monsters for T1 (`Tab`).
    pub fn t1_candidates(&self) -> Vec<(EntityId, String)> {
        self.combat_candidates()
    }

    /// Allies first, then monsters, for T2 (`Shift+Tab`). Includes self for heals.
    pub fn t2_candidates(&self) -> Vec<(EntityId, String)> {
        let (px, py) = self.player_position();
        let dist = |id: EntityId| {
            self.entities
                .iter()
                .find(|e| e.id == id)
                .map(|e| distance(px, py, e.transform.position.x, e.transform.position.y))
                .unwrap_or(f32::MAX)
        };

        let mut allies = Vec::new();
        // Self first — heal_touch on T2.
        if let Some(me) = self.player.as_ref() {
            let alive = me
                .vitals
                .as_ref()
                .map(|v| v.life_state == LifeState::Alive && v.health > 0.0)
                .unwrap_or(true);
            if alive {
                allies.push((self.entity_id, "Yourself".into()));
            }
        }
        for entity in &self.entities {
            if entity.id == self.entity_id {
                continue;
            }
            if entity.vitals.is_some() {
                let alive = entity
                    .vitals
                    .as_ref()
                    .map(|v| v.life_state == LifeState::Alive && v.health > 0.0)
                    .unwrap_or(true);
                if alive {
                    allies.push((entity.id, entity.label.clone()));
                }
            }
        }
        allies.sort_by(|(a, _), (b, _)| {
            if *a == self.entity_id {
                return std::cmp::Ordering::Less;
            }
            if *b == self.entity_id {
                return std::cmp::Ordering::Greater;
            }
            dist(*a)
                .partial_cmp(&dist(*b))
                .unwrap_or(std::cmp::Ordering::Equal)
        });

        let mut monsters = self.combat_candidates();
        monsters.retain(|(id, _)| !allies.iter().any(|(aid, _)| aid == id));
        allies.into_iter().chain(monsters).collect()
    }

    fn candidates_for_slot(&self, slot_index: u8) -> Vec<(EntityId, String)> {
        match slot_index {
            2 => self.t2_candidates(),
            _ => self.t1_candidates(),
        }
    }

    /// Full client reset after Welcome (initial connect or reconnect).
    pub(crate) fn restore_from_welcome(
        &mut self,
        session_id: SessionId,
        entity_id: EntityId,
        snapshot: &flatland_protocol::Snapshot,
    ) {
        self.clear_harvest_state();
        self.disconnect_reason = None;
        self.show_stats = false;
        self.show_craft_menu = false;
        self.show_shop_menu = false;
        self.shop_catalog = None;
        self.show_inventory_menu = false;
        self.session_id = session_id;
        self.entity_id = entity_id;
        self.connected = true;
        self.apply_snapshot_fields(snapshot, entity_id);
        if let Some(combat) = &snapshot.combat {
            self.apply_combat_hud(combat);
            let stacks = self.inventory_stacks.clone();
            self.sync_inventory_from_stacks(&stacks);
        }
    }

    fn apply_tick_fields(&mut self, delta: &flatland_protocol::TickDelta, entity_id: EntityId) {
        self.tick = delta.tick;
        self.world_clock = delta.world_clock;

        // Degenerate AOI tick (observer missing server-side): keep welcome snapshot layers.
        if delta.entities.is_empty() {
            if let Some(combat) = &delta.combat {
                self.apply_combat_hud(combat);
                let stacks = self.inventory_stacks.clone();
                self.sync_inventory_from_stacks(&stacks);
            }
            return;
        }
        if !delta.buildings.is_empty() {
            self.buildings = delta.buildings.clone();
        }
        if !delta.blueprints.is_empty() {
            self.blueprints = delta.blueprints.clone();
        }
        self.sync_inventory_from_stacks(&delta.inventory);

        if let Some(updated) = delta.entities.iter().find(|e| e.id == entity_id) {
            self.player = Some(updated.clone());
        }
        self.entities = delta.entities.clone();
        if self.player.is_none() {
            self.player = self.entities.iter().find(|e| e.id == entity_id).cloned();
        }

        self.sync_interior_map_context();

        // Static world layers: ticks often omit these (indoors, or unchanged).
        // Never wipe the welcome snapshot with an empty vec.
        if !delta.resource_nodes.is_empty() {
            self.resource_nodes = delta.resource_nodes.clone();
        }
        if self
            .player
            .as_ref()
            .is_none_or(|p| p.inside_building.is_none())
        {
            self.ground_drops = delta.ground_drops.clone();
            self.placed_containers = delta.placed_containers.clone();
        }
        if !delta.doors.is_empty() {
            self.doors = delta.doors.clone();
        }
        if self.effective_inside_building().is_some() {
            if let Some(map) = &delta.interior_map {
                self.interior_map = Some(map.clone());
            }
        } else {
            self.interior_map = None;
        }
        if !delta.npcs.is_empty() {
            self.npcs = delta.npcs.clone();
        }
        if !delta.quest_log.is_empty() {
            self.quest_log = delta.quest_log.clone();
        }
        if !delta.interactables.is_empty() {
            self.interactables = delta.interactables.clone();
        }
        if let Some(combat) = &delta.combat {
            self.apply_combat_hud(combat);
            let stacks = self.inventory_stacks.clone();
            self.sync_inventory_from_stacks(&stacks);
        } else {
            self.refresh_inventory_ui();
        }
    }

    /// Wildlife and other combat targets visible in AOI (`NpcView.entity_id`).
    pub fn combat_candidates(&self) -> Vec<(EntityId, String)> {
        let (px, py) = self.player_position();
        let mut out = Vec::new();
        for npc in &self.npcs {
            let Some(eid) = npc.entity_id else {
                continue;
            };
            let alive = npc.life_state.is_none_or(|s| s == LifeState::Alive);
            let has_hp = npc.hp_pct.is_none_or(|h| h > 0.0);
            if alive && has_hp {
                out.push((eid, npc.label.clone()));
            }
        }
        out.sort_by(|(a_id, a_label), (b_id, b_label)| {
            let dist = |id: EntityId| {
                self.entities
                    .iter()
                    .find(|e| e.id == id)
                    .map(|e| distance(px, py, e.transform.position.x, e.transform.position.y))
                    .unwrap_or(f32::MAX)
            };
            dist(*a_id)
                .partial_cmp(&dist(*b_id))
                .unwrap_or(std::cmp::Ordering::Equal)
                .then_with(|| a_label.cmp(b_label))
                .then_with(|| a_id.cmp(b_id))
        });
        out
    }

    pub fn refresh_combat_target_label(&mut self) {
        let Some(id) = self.combat_target else {
            return;
        };
        if let Some((_, label)) = self
            .combat_candidates()
            .into_iter()
            .find(|(eid, _)| *eid == id)
        {
            self.combat_target_label = Some(label);
        } else if let Some(label) = self
            .entities
            .iter()
            .find(|e| e.id == id)
            .map(|e| e.label.clone())
        {
            self.combat_target_label = Some(label);
        }
    }

    pub fn active_quest_entries(&self) -> Vec<&flatland_protocol::QuestLogEntry> {
        self.quest_log
            .iter()
            .filter(|q| q.status == flatland_protocol::QuestStatusView::Active)
            .collect()
    }

    pub fn tracked_quest(&self) -> Option<&flatland_protocol::QuestLogEntry> {
        self.quest_log
            .iter()
            .find(|q| q.is_tracked && q.status == flatland_protocol::QuestStatusView::Active)
            .or_else(|| {
                self.quest_log
                    .iter()
                    .find(|q| q.status == flatland_protocol::QuestStatusView::Active)
            })
    }

    /// Nearest interactable target for `f` (doors, NPCs, well, shallow water).
    pub fn nearest_interact_target(&self) -> Option<String> {
        let (px, py) = self.player_position();
        let inside = self.effective_inside_building();

        #[derive(Clone, Copy, PartialEq, Eq)]
        enum Kind {
            Npc,
            QuestBoard,
            ExitDoor,
            EnterDoor,
            Well,
            Water,
        }

        fn kind_priority(kind: Kind) -> u8 {
            match kind {
                Kind::Npc => 0,
                Kind::QuestBoard => 1,
                Kind::ExitDoor => 2,
                Kind::EnterDoor => 3,
                Kind::Well => 4,
                Kind::Water => 5,
            }
        }

        let mut best: Option<(f32, Kind, String)> = None;

        let mut consider = |dist: f32, max: f32, kind: Kind, id: String| {
            if dist > max {
                return;
            }
            let replace = match best {
                None => true,
                Some((bd, _bk, _)) if dist < bd - 0.05 => true,
                Some((bd, bk, _)) if (dist - bd).abs() <= 0.05 => {
                    kind_priority(kind) < kind_priority(bk)
                }
                _ => false,
            };
            if replace {
                best = Some((dist, kind, id));
            }
        };

        for npc in &self.npcs {
            consider(
                distance(px, py, npc.x, npc.y),
                INTERACTION_RADIUS_M,
                Kind::Npc,
                npc.id.clone(),
            );
        }

        for door in &self.doors {
            if let Some(ref bid) = inside {
                if door.building_id != *bid {
                    continue;
                }
                let is_exit = door.portal.is_some();
                let max = if is_exit {
                    INTERACTION_RADIUS_M
                } else {
                    DOOR_INTERACTION_RADIUS_M
                };
                let kind = if is_exit {
                    Kind::ExitDoor
                } else {
                    Kind::EnterDoor
                };
                consider(distance(px, py, door.x, door.y), max, kind, door.id.clone());
                continue;
            }
            consider(
                distance(px, py, door.x, door.y),
                DOOR_INTERACTION_RADIUS_M,
                Kind::EnterDoor,
                door.id.clone(),
            );
        }

        if inside.is_none() {
            for inter in &self.interactables {
                if inter.kind == "quest_board" {
                    consider(
                        distance(px, py, inter.x, inter.y),
                        QUEST_BOARD_INTERACTION_RADIUS_M,
                        Kind::QuestBoard,
                        inter.id.clone(),
                    );
                }
            }
            for building in &self.buildings {
                if !building.tags.iter().any(|t| t == "well") {
                    continue;
                }
                consider(
                    distance(px, py, building.x, building.y),
                    INTERACTION_RADIUS_M,
                    Kind::Well,
                    building.id.clone(),
                );
            }
            if self.in_shallow_water() {
                consider(
                    0.0,
                    INTERACTION_RADIUS_M,
                    Kind::Water,
                    "water_source".into(),
                );
            }
        }

        best.map(|(_, _, id)| id)
    }

    /// Nearest quest board and distance (any distance), for out-of-range feedback.
    pub fn nearest_quest_board(&self) -> Option<(String, f32)> {
        if self.effective_inside_building().is_some() {
            return None;
        }
        let (px, py) = self.player_position();
        self.interactables
            .iter()
            .filter(|i| i.kind == "quest_board")
            .map(|i| {
                let label = if i.label.is_empty() {
                    "Quest board".to_string()
                } else {
                    i.label.clone()
                };
                (label, distance(px, py, i.x, i.y))
            })
            .min_by(|a, b| a.1.partial_cmp(&b.1).unwrap_or(std::cmp::Ordering::Equal))
    }

    /// Human-readable template name from synced catalog hints.
    pub fn template_display_name(&self, template_id: &str) -> String {
        self.inventory_hints
            .get(template_id)
            .map(|h| h.display_name.clone())
            .filter(|n| !n.is_empty())
            .unwrap_or_else(|| humanize_template_id(template_id))
    }

    /// Chest label for the location panel — generic type unless this player owns it.
    pub fn placed_container_public_label(
        &self,
        c: &flatland_protocol::PlacedContainerView,
    ) -> String {
        let is_owner = match (self.character_id, c.owner_character_id) {
            (Some(me), Some(owner)) => me == owner,
            _ => false,
        };
        if is_owner {
            c.display_name.clone()
        } else {
            self.template_display_name(&c.template_id)
        }
    }

    /// Keys on person and stowed on the keychain for the keychain overlay.
    pub fn keychain_entries(&self) -> Vec<KeychainEntry> {
        let mut out = Vec::new();
        for stack in &self.inventory_stacks {
            if stack.template_id == KEY_TEMPLATE {
                out.push(KeychainEntry {
                    stack: stack.clone(),
                    stowed: false,
                });
            }
        }
        for stack in &self.keychain_stacks {
            if stack.template_id == KEY_TEMPLATE {
                out.push(KeychainEntry {
                    stack: stack.clone(),
                    stowed: true,
                });
            }
        }
        out
    }

    /// Display name of the chest a `container_key` opens, when known on the client.
    pub fn key_pair_chest_label(&self, stack: &flatland_protocol::ItemStack) -> Option<String> {
        if stack.template_id != KEY_TEMPLATE {
            return None;
        }
        if let Some(name) = stack
            .props
            .get(PROP_OPENS_CONTAINER_NAME)
            .filter(|n| !n.is_empty())
        {
            return Some(name.clone());
        }
        let opens = stack.props.get(PROP_OPENS_LOCK_ID)?;
        self.container_name_for_lock_id(opens)
    }

    /// Keys always show the catalog name — never a chest rename or stray `custom_name`.
    pub fn key_inventory_label(&self, stack: &flatland_protocol::ItemStack) -> String {
        if stack.template_id == KEY_TEMPLATE {
            self.template_display_name(KEY_TEMPLATE)
        } else {
            stack
                .display_name
                .clone()
                .unwrap_or_else(|| stack.template_id.clone())
        }
    }

    /// Hint suffix for a key row (`[key for …]` or `[key — unpaired]`).
    pub fn key_inventory_hint(&self, stack: &flatland_protocol::ItemStack) -> String {
        if stack.template_id != KEY_TEMPLATE {
            return String::new();
        }
        match self.key_pair_chest_label(stack) {
            Some(chest) if self.key_drop_blocked(stack) => {
                format!(" [key for {chest} — can't drop while locked]")
            }
            Some(chest) => format!(" [key for {chest}]"),
            None => " [key — unpaired]".into(),
        }
    }

    /// Resolve a lock id to a container label (placed chest or one still on your person).
    pub fn container_name_for_lock_id(&self, lock: &str) -> Option<String> {
        for c in &self.placed_containers {
            if c.lock_id.as_deref() == Some(lock) {
                return Some(c.display_name.clone());
            }
        }
        Self::container_name_in_stacks(&self.inventory_stacks, lock).or_else(|| {
            self.worn
                .values()
                .find_map(|worn| Self::container_name_in_stacks(std::slice::from_ref(worn), lock))
        })
    }

    /// Keys cannot be dropped while their paired chest is locked.
    pub fn key_drop_blocked(&self, stack: &flatland_protocol::ItemStack) -> bool {
        if stack.template_id != KEY_TEMPLATE {
            return false;
        }
        let Some(opens) = stack.props.get(PROP_OPENS_LOCK_ID) else {
            return false;
        };
        for c in &self.placed_containers {
            if c.lock_id.as_deref() == Some(opens.as_str()) && c.locked {
                return true;
            }
        }
        if Self::has_locked_container_with_lock(&self.inventory_stacks, opens) {
            return true;
        }
        self.worn
            .values()
            .any(|worn| Self::has_locked_container_with_lock(std::slice::from_ref(worn), opens))
    }

    fn container_name_in_stacks(
        stacks: &[flatland_protocol::ItemStack],
        lock: &str,
    ) -> Option<String> {
        fn walk(stacks: &[flatland_protocol::ItemStack], lock: &str) -> Option<String> {
            for s in stacks {
                if s.props.get(PROP_LOCK_ID) == Some(&lock.to_string()) {
                    return Some(GameState::stack_container_label(s));
                }
                if let Some(name) = walk(&s.contents, lock) {
                    return Some(name);
                }
            }
            None
        }
        walk(stacks, lock)
    }

    fn stack_container_label(stack: &flatland_protocol::ItemStack) -> String {
        stack
            .props
            .get(PROP_CUSTOM_NAME)
            .cloned()
            .or_else(|| stack.display_name.clone())
            .unwrap_or_else(|| stack.template_id.clone())
    }

    fn has_locked_container_with_lock(stacks: &[flatland_protocol::ItemStack], lock: &str) -> bool {
        fn walk(stacks: &[flatland_protocol::ItemStack], lock: &str) -> bool {
            for s in stacks {
                if s.props.get(PROP_LOCK_ID) == Some(&lock.to_string()) && stack_is_locked(s) {
                    return true;
                }
                if walk(&s.contents, lock) {
                    return true;
                }
            }
            false
        }
        walk(stacks, lock)
    }

    fn stack_for_instance(&self, instance_id: uuid::Uuid) -> Option<flatland_protocol::ItemStack> {
        if let Some(stack) = self.find_stack_by_instance(&self.inventory_stacks, instance_id) {
            return Some(stack.clone());
        }
        for worn in self.worn.values() {
            if worn.item_instance_id == Some(instance_id) {
                return Some(worn.clone());
            }
            if let Some(stack) = self.find_stack_by_instance(&worn.contents, instance_id) {
                return Some(stack.clone());
            }
        }
        None
    }

    /// Terrain, interactables, and map objects near the player for the HUD location panel.
    pub fn location_context_lines(&self) -> Vec<ContextLine> {
        let (px, py) = self.player_position();
        let inside = self.effective_inside_building();
        let mut lines = Vec::new();

        if let Some(kind) = self.terrain_at(px, py) {
            lines.push(ContextLine {
                on_top: true,
                text: format!("Terrain: {}", terrain_kind_label(kind)),
            });
        }

        if let Some(id) = inside.as_ref() {
            if let Some(b) = self.buildings.iter().find(|b| &b.id == id) {
                lines.push(ContextLine {
                    on_top: true,
                    text: format!("Inside: {}", b.label),
                });
            }
        }

        let mut nearby: Vec<(f32, ContextLine)> = Vec::new();

        for node in &self.resource_nodes {
            let dist = distance(px, py, node.x, node.y);
            if dist > NEARBY_SCAN_M {
                continue;
            }
            let on_top = dist <= ON_TOP_RADIUS_M;
            let state = match node.state {
                flatland_protocol::ResourceNodeState::Available => " — f harvest",
                flatland_protocol::ResourceNodeState::Harvesting => " (being harvested)",
                flatland_protocol::ResourceNodeState::Cooldown => " (depleted)",
            };
            let prefix = if on_top { "On" } else { "Near" };
            nearby.push((
                dist,
                ContextLine {
                    on_top,
                    text: format!("{prefix}: {} ({dist:.1}m){state}", node.label),
                },
            ));
        }

        for drop in &self.ground_drops {
            let dist = distance(px, py, drop.x, drop.y);
            if dist > INTERACTION_RADIUS_M {
                continue;
            }
            let on_top = dist <= ON_TOP_RADIUS_M;
            let name = self.template_display_name(&drop.template_id);
            let prefix = if on_top { "On" } else { "Near" };
            let qty = if drop.quantity > 1 {
                format!(" ×{}", drop.quantity)
            } else {
                String::new()
            };
            nearby.push((
                dist,
                ContextLine {
                    on_top,
                    text: format!("{prefix}: {name}{qty} ({dist:.1}m) — f pickup"),
                },
            ));
        }

        for c in &self.placed_containers {
            let dist = distance(px, py, c.x, c.y);
            if dist > CONTAINER_RANGE_M {
                continue;
            }
            let on_top = dist <= ON_TOP_RADIUS_M;
            let name = self.placed_container_public_label(c);
            let lock = if c.locked { " [locked]" } else { "" };
            let prefix = if on_top { "On" } else { "Near" };
            nearby.push((
                dist,
                ContextLine {
                    on_top,
                    text: format!("{prefix}: {name}{lock} ({dist:.1}m) — f pickup"),
                },
            ));
        }

        for npc in &self.npcs {
            let dist = distance(px, py, npc.x, npc.y);
            if dist > NEARBY_SCAN_M {
                continue;
            }
            let on_top = dist <= ON_TOP_RADIUS_M;
            let prefix = if on_top { "On" } else { "Near" };
            nearby.push((
                dist,
                ContextLine {
                    on_top,
                    text: format!("{prefix}: {} ({dist:.1}m) — f talk", npc.label),
                },
            ));
        }

        for door in &self.doors {
            let dist = distance(px, py, door.x, door.y);
            if dist > DOOR_INTERACTION_RADIUS_M {
                continue;
            }
            let building = self
                .buildings
                .iter()
                .find(|b| b.id == door.building_id)
                .map(|b| b.label.as_str())
                .unwrap_or(door.building_id.as_str());
            let action = if inside.is_some() && door.portal.is_some() {
                "exit"
            } else {
                "enter"
            };
            nearby.push((
                dist,
                ContextLine {
                    on_top: dist <= ON_TOP_RADIUS_M,
                    text: format!("{building} door ({dist:.1}m) — f {action}"),
                },
            ));
        }

        if inside.is_none() {
            for inter in &self.interactables {
                if inter.kind != "quest_board" {
                    continue;
                }
                let dist = distance(px, py, inter.x, inter.y);
                if dist > QUEST_BOARD_INTERACTION_RADIUS_M {
                    continue;
                }
                let on_top = dist <= ON_TOP_RADIUS_M;
                let prefix = if on_top { "On" } else { "Near" };
                let label = if inter.label.is_empty() {
                    "Quest board".to_string()
                } else {
                    inter.label.clone()
                };
                nearby.push((
                    dist,
                    ContextLine {
                        on_top,
                        text: format!("{prefix}: {label} ({dist:.1}m) — f view quests"),
                    },
                ));
            }
        }

        if self.in_shallow_water() {
            let already = self
                .terrain_at(px, py)
                .is_some_and(|k| k == flatland_protocol::TerrainKindView::ShallowWater);
            if !already {
                nearby.push((
                    0.0,
                    ContextLine {
                        on_top: true,
                        text: "Shallow water — f fill bottle".into(),
                    },
                ));
            } else if let Some(line) = lines.iter_mut().find(|l| l.text.starts_with("Terrain:")) {
                line.text.push_str(" — f fill bottle");
            }
        }

        for entity in &self.entities {
            if entity.id == self.entity_id {
                continue;
            }
            let dist = distance(
                px,
                py,
                entity.transform.position.x,
                entity.transform.position.y,
            );
            if dist > NEARBY_SCAN_M {
                continue;
            }
            let label = if entity.label.is_empty() {
                format!("entity {}", entity.id)
            } else {
                entity.label.clone()
            };
            nearby.push((
                dist,
                ContextLine {
                    on_top: dist <= ON_TOP_RADIUS_M,
                    text: format!("Near: {label} ({dist:.1}m)"),
                },
            ));
        }

        nearby.sort_by(|a, b| {
            a.0.partial_cmp(&b.0)
                .unwrap_or(std::cmp::Ordering::Equal)
                .then_with(|| a.1.on_top.cmp(&b.1.on_top).reverse())
        });
        lines.extend(nearby.into_iter().map(|(_, l)| l));

        if lines.is_empty() {
            lines.push(ContextLine {
                on_top: false,
                text: "(nothing notable nearby)".into(),
            });
        }

        lines
    }
}

/// HUD line for the location / nearby panel.
#[derive(Debug, Clone)]
pub struct ContextLine {
    pub on_top: bool,
    pub text: String,
}

const ON_TOP_RADIUS_M: f32 = 0.65;
const NEARBY_SCAN_M: f32 = 5.0;

fn terrain_kind_label(kind: flatland_protocol::TerrainKindView) -> &'static str {
    use flatland_protocol::TerrainKindView;
    match kind {
        TerrainKindView::Grass => "Grass",
        TerrainKindView::Hill => "Hills",
        TerrainKindView::Bog => "Bog",
        TerrainKindView::ShallowWater => "Shallow water",
        TerrainKindView::DeepWater => "Deep water",
        TerrainKindView::Trail => "Trail",
        TerrainKindView::Rock => "Rock",
    }
}

fn humanize_template_id(template_id: &str) -> String {
    template_id
        .split('_')
        .map(|word| {
            let mut chars = word.chars();
            match chars.next() {
                None => String::new(),
                Some(first) => first.to_uppercase().collect::<String>() + chars.as_str(),
            }
        })
        .collect::<Vec<_>>()
        .join(" ")
}

/// Keep in sync with `flatland_sim::INTERACTION_RADIUS_M`.
const HARVEST_RANGE_M: f32 = 1.5;

pub struct GameClient<S: PlayConnection> {
    session: S,
    seq: Seq,
    pub state: GameState,
    last_move_forward: f32,
    last_move_strafe: f32,
}

impl<S: PlayConnection> GameClient<S> {
    pub fn new(session: S) -> Self {
        let session_id = session.session_id();
        let entity_id = session.entity_id();
        Self {
            session,
            seq: 0,
            last_move_forward: 0.0,
            last_move_strafe: 0.0,
            state: GameState {
                session_id,
                entity_id,
                character_id: None,
                tick: 0,
                chunk_rev: 0,
                content_rev: 0,
                entities: Vec::new(),
                player: None,
                resource_nodes: Vec::new(),
                ground_drops: Vec::new(),
                placed_containers: Vec::new(),
                buildings: Vec::new(),
                doors: Vec::new(),
                interior_map: None,
                npcs: Vec::new(),
                blueprints: Vec::new(),
                world_width_m: 0.0,
                world_height_m: 0.0,
                terrain_zones: Vec::new(),
                z_platforms: Vec::new(),
                z_transitions: Vec::new(),
                world_clock: flatland_protocol::WorldClock::default(),
                inventory: std::collections::HashMap::new(),
                inventory_hints: std::collections::HashMap::new(),
                logs: VecDeque::new(),
                intents_sent: 0,
                ticks_received: 0,
                connected: false,
                disconnect_reason: None,
                show_stats: false,
                show_craft_menu: false,
                craft_menu_index: 0,
                craft_batch_quantity: 1,
                show_shop_menu: false,
                shop_catalog: None,
                shop_tab: ShopTab::default(),
                shop_menu_index: 0,
                shop_quantity: 1,
                shop_trade_log: VecDeque::new(),
                show_npc_verb_menu: false,
                npc_verb_target: None,
                npc_verb_index: 0,
                show_npc_chat: false,
                npc_chat: None,
                show_inventory_menu: false,
                inventory_menu_index: 0,
                show_move_picker: false,
                show_rename_prompt: false,
                rename_buffer: String::new(),
                move_picker_index: 0,
                move_picker: None,
                show_destroy_picker: false,
                destroy_confirm_pending: false,
                destroy_picker: None,
                combat_target: None,
                combat_target_label: None,
                in_combat: false,
                auto_attack: true,
                combat_has_los: false,
                attack_cd_ticks: 0,
                gcd_ticks: 0,
                weapon_ability_id: "unarmed".into(),
                mainhand_template_id: None,
                mainhand_label: None,
                worn: BTreeMap::new(),
                carry_mass: 0.0,
                carry_mass_max: 0.0,
                encumbrance: flatland_protocol::EncumbranceState::Light,
                inventory_stacks: Vec::new(),
                keychain_stacks: Vec::new(),
                combat_target_detail: None,
                cast_progress: None,
                ability_cooldowns: Vec::new(),
                blocking_active: false,
                max_target_slots: 1,
                combat_slots: Vec::new(),
                rotation_presets: Vec::new(),
                show_loadout_menu: false,
                show_keychain_menu: false,
                keychain_menu_index: 0,
                show_rotation_editor: false,
                loadout_menu_index: 0,
                rotation_editor: RotationEditorState::default(),
                harvest_in_progress: false,
                harvest_started_at: None,
                pending_craft_ack: None,
                quest_log: Vec::new(),
                interactables: Vec::new(),
                show_quest_offer: false,
                pending_quest_offer: None,
                show_quest_menu: false,
                quest_menu_index: 0,
                quest_withdraw_confirm: false,
                progression_curve: None,
            },
        }
    }

    pub fn entity_id(&self) -> EntityId {
        self.state.entity_id
    }

    pub async fn wait_until_ready(&mut self) -> anyhow::Result<()> {
        if self.state.connected {
            return Ok(());
        }

        loop {
            match self.session.next_event().await {
                Some(SessionEvent::Welcome {
                    session_id,
                    entity_id,
                    snapshot,
                }) => {
                    self.state
                        .restore_from_welcome(session_id, entity_id, &snapshot);
                    self.state.push_log(format!(
                        "Connected — session {session_id}, entity {entity_id}"
                    ));
                    return Ok(());
                }
                Some(SessionEvent::Disconnected { .. }) => {
                    anyhow::bail!("disconnected before welcome");
                }
                Some(_) => continue,
                None => anyhow::bail!("session closed before welcome"),
            }
        }
    }

    /// Drain all pending server events (non-blocking).
    pub fn drain_events(&mut self) {
        while let Some(event) = self.session.try_next_event() {
            if self.handle_event_sync(event).is_err() {
                break;
            }
        }
    }

    /// Wait for the next server event.
    pub async fn next_event(&mut self) -> Option<SessionEvent> {
        self.session.next_event().await
    }

    pub async fn handle_event(&mut self, event: SessionEvent) -> anyhow::Result<()> {
        self.handle_event_sync(event)
    }

    fn handle_event_sync(&mut self, event: SessionEvent) -> anyhow::Result<()> {
        match event {
            SessionEvent::Welcome {
                session_id,
                entity_id,
                snapshot,
            } => {
                let resumed = self.state.connected;
                self.state
                    .restore_from_welcome(session_id, entity_id, &snapshot);
                if resumed {
                    self.state.push_log(format!(
                        "Session restored — session {session_id}, entity {entity_id}"
                    ));
                }
            }
            SessionEvent::ContentUpdated { snapshot } => {
                self.state
                    .apply_snapshot_fields(&snapshot, self.state.entity_id);
                self.state.push_log(format!(
                    "World updated (content rev {})",
                    snapshot.content_rev
                ));
            }
            SessionEvent::Tick(delta) => {
                self.state.apply_tick_fields(&delta, self.state.entity_id);
                self.state.ticks_received += 1;
            }
            SessionEvent::IntentAck {
                entity_id,
                seq,
                tick,
            } => {
                crate::harvest_trace!(entity_id, seq, tick, "client received intent ack");
                if let Some((craft_seq, _, _)) = &self.state.pending_craft_ack {
                    if *craft_seq == seq {
                        let (_, label, batches) = self.state.pending_craft_ack.take().unwrap();
                        if batches > 1 {
                            self.state.push_log(format!("Crafting {label} ×{batches}…"));
                        } else {
                            self.state.push_log(format!("Crafting {label}…"));
                        }
                    }
                }
            }
            SessionEvent::Chat(msg) => {
                let label = match msg.channel {
                    flatland_protocol::ChatChannel::Nearby => "nearby",
                    flatland_protocol::ChatChannel::WhisperStone => "whisper",
                };
                self.state
                    .push_log(format!("[{label}] {}: {}", msg.from_name, msg.text));
            }
            SessionEvent::HarvestResult(result) => {
                self.state.clear_harvest_state();
                crate::harvest_trace!(
                    entity_id = self.state.entity_id,
                    node_id = %result.node_id,
                    template = %result.item_template,
                    quantity = result.quantity,
                    client_tick = self.state.tick,
                    "client applied harvest result"
                );
                self.state.push_log(format!(
                    "Harvested {} x{} (on the ground — press P to pick up)",
                    result.item_template, result.quantity
                ));
            }
            SessionEvent::CraftResult(result) => {
                for stack in &result.consumed {
                    if let Some(qty) = self.state.inventory.get_mut(&stack.template_id) {
                        *qty = qty.saturating_sub(stack.quantity);
                        if *qty == 0 {
                            self.state.inventory.remove(&stack.template_id);
                        }
                    }
                }
                for stack in &result.outputs {
                    *self
                        .state
                        .inventory
                        .entry(stack.template_id.clone())
                        .or_insert(0) += stack.quantity;
                }
                if let Some(output) = result.outputs.first() {
                    if result.batch_total > 1 {
                        self.state.push_log(format!(
                            "Crafted {} x{} ({}/{})",
                            output.template_id,
                            output.quantity,
                            result.batch_index,
                            result.batch_total
                        ));
                    } else {
                        self.state.push_log(format!(
                            "Crafted {} x{}",
                            output.template_id, output.quantity
                        ));
                    }
                } else {
                    self.state
                        .push_log(format!("Craft finished: {}", result.blueprint_id));
                }
            }
            SessionEvent::Death(notice) => {
                self.state.clear_harvest_state();
                self.state.push_log(notice.message.clone());
                self.state.push_log(format!(
                    "Respawned at ({:.1}, {:.1})",
                    notice.respawn_x, notice.respawn_y
                ));
            }
            SessionEvent::Interaction(notice) => {
                if notice.message.starts_with("Harvest failed:") {
                    self.state.clear_harvest_state();
                }
                if notice.message.starts_with("Can't do that:") {
                    self.state.pending_craft_ack = None;
                }
                if notice.message.starts_with("Cast failed:") {
                    self.state.cast_progress = None;
                }
                if notice.message.contains("slain the") {
                    self.state.combat_target = None;
                    self.state.combat_target_label = None;
                }
                self.state.apply_interaction_notice(&notice);
                self.state.push_log(notice.message.clone());
            }
            SessionEvent::ShopOpened(catalog) => {
                self.state.apply_shop_catalog(catalog);
            }
            SessionEvent::NpcTalkOpened(opened) => {
                let label = opened.npc_label.clone();
                self.state.show_npc_chat = true;
                self.state.npc_chat = Some(NpcChatState {
                    npc_id: opened.npc_id,
                    npc_label: opened.npc_label,
                    lines: vec![format!("{label}: {}", opened.greeting)],
                    input: String::new(),
                    pending: false,
                });
            }
            SessionEvent::NpcTalkPending(_) => {
                if let Some(chat) = self.state.npc_chat.as_mut() {
                    chat.pending = true;
                }
            }
            SessionEvent::NpcTalkReply(reply) => {
                if let Some(chat) = self.state.npc_chat.as_mut() {
                    if chat.npc_id == reply.npc_id {
                        chat.pending = false;
                        chat.lines
                            .push(format!("{}: {}", chat.npc_label, reply.line));
                    }
                }
            }
            SessionEvent::NpcTalkClosed(closed) => {
                if self
                    .state
                    .npc_chat
                    .as_ref()
                    .is_some_and(|c| c.npc_id == closed.npc_id)
                {
                    self.state.show_npc_chat = false;
                    self.state.npc_chat = None;
                }
            }
            SessionEvent::NpcTalkError(err) => {
                self.state.push_log(format!("Talk failed: {}", err.reason));
                if let Some(chat) = self.state.npc_chat.as_mut() {
                    chat.pending = false;
                }
            }
            SessionEvent::UseResult(result) => {
                if let Some(qty) = self.state.inventory.get_mut(&result.template_id) {
                    *qty = qty.saturating_sub(1);
                    if *qty == 0 {
                        self.state.inventory.remove(&result.template_id);
                    }
                }
                let mut parts = Vec::new();
                if result.health_restored > 0.0 {
                    parts.push(format!("+{:.0} health", result.health_restored));
                }
                if result.mana_restored > 0.0 {
                    parts.push(format!("+{:.0} mana", result.mana_restored));
                }
                if result.hunger_restored > 0.0 {
                    parts.push(format!("+{:.0} hunger", result.hunger_restored));
                }
                if result.thirst_restored > 0.0 {
                    parts.push(format!("+{:.0} thirst", result.thirst_restored));
                }
                for id in &result.cleared_dot_ids {
                    parts.push(format!("cleared {id}"));
                }
                let detail = if parts.is_empty() {
                    String::new()
                } else {
                    format!(" ({})", parts.join(", "))
                };
                self.state
                    .push_log(format!("Consumed {}{detail}", result.template_id));
            }
            SessionEvent::QuestOffer(offer) => {
                self.state.pending_quest_offer = Some(offer.clone());
                self.state.show_quest_offer = true;
                self.state
                    .push_log(format!("Quest offered: {}", offer.title));
            }
            SessionEvent::QuestAccepted(notice) => {
                self.state.show_quest_offer = false;
                self.state.pending_quest_offer = None;
                self.state.push_log(notice.message);
            }
            SessionEvent::QuestWithdrawn(notice) => {
                self.state.show_quest_menu = false;
                self.state.quest_withdraw_confirm = false;
                self.state.push_log(notice.message);
            }
            SessionEvent::QuestStepCompleted(notice) => {
                self.state.push_log(notice.message);
            }
            SessionEvent::QuestCompleted(notice) => {
                self.state.push_log(notice.message);
            }
            SessionEvent::Disconnected { reason } => {
                self.state.clear_harvest_state();
                self.state.connected = false;
                self.state.disconnect_reason = reason.clone().filter(|s| !s.is_empty());
                if let Some(r) = &self.state.disconnect_reason {
                    self.state.push_log(format!("Disconnected: {r}"));
                } else {
                    self.state.push_log("Disconnected from server");
                }
            }
        }
        Ok(())
    }

    pub fn is_connected(&self) -> bool {
        self.state.connected
    }

    pub fn close_overlays(&mut self) {
        self.state.show_stats = false;
        self.state.show_craft_menu = false;
        self.state.show_shop_menu = false;
        self.state.shop_catalog = None;
        self.state.show_npc_verb_menu = false;
        self.state.npc_verb_target = None;
        self.state.show_npc_chat = false;
        self.state.npc_chat = None;
        self.state.show_inventory_menu = false;
        self.state.show_loadout_menu = false;
        self.state.show_rotation_editor = false;
        self.state.rotation_editor.reset();
        self.state.show_rename_prompt = false;
        self.state.rename_buffer.clear();
        self.state.show_move_picker = false;
        self.state.move_picker = None;
        self.state.show_destroy_picker = false;
        self.state.destroy_confirm_pending = false;
        self.state.destroy_picker = None;
        self.state.show_quest_offer = false;
        self.state.pending_quest_offer = None;
        self.state.show_quest_menu = false;
        self.state.quest_withdraw_confirm = false;
    }

    /// Esc / back — pop one UI layer instead of closing every overlay at once.
    pub fn back_on_esc(&mut self) -> bool {
        if self.state.show_rename_prompt {
            self.cancel_rename_prompt();
            return true;
        }
        if self.state.show_destroy_picker {
            if self.state.destroy_confirm_pending {
                self.cancel_destroy_confirm();
            } else {
                self.close_destroy_picker();
            }
            return true;
        }
        if self.state.show_move_picker {
            self.close_move_picker();
            return true;
        }
        if self.state.show_rotation_editor {
            match self.state.rotation_editor.mode {
                RotationEditorMode::List => {
                    self.state.show_rotation_editor = false;
                    self.state.rotation_editor.reset();
                }
                RotationEditorMode::EditLabel => {
                    self.state.rotation_editor.label_buffer.clear();
                    self.state.rotation_editor.mode = RotationEditorMode::EditSequence;
                }
                RotationEditorMode::PickAbility => {
                    self.state.rotation_editor.mode = RotationEditorMode::EditSequence;
                }
                RotationEditorMode::EditSequence => {
                    self.state.rotation_editor.draft = None;
                    self.state.rotation_editor.mode = RotationEditorMode::List;
                }
            }
            return true;
        }
        if self.state.show_inventory_menu {
            self.close_inventory_menu();
            return true;
        }
        if self.state.show_craft_menu {
            self.close_craft_menu();
            return true;
        }
        if self.state.show_shop_menu {
            self.close_shop_menu();
            return true;
        }
        if self.state.show_npc_chat {
            // play.rs calls npc_talk_close().await on Esc
            return false;
        }
        if self.state.show_npc_verb_menu {
            self.state.show_npc_verb_menu = false;
            self.state.npc_verb_target = None;
            return true;
        }
        if self.state.show_quest_offer {
            self.state.show_quest_offer = false;
            self.state.pending_quest_offer = None;
            return true;
        }
        if self.state.show_quest_menu {
            if self.state.quest_withdraw_confirm {
                self.state.quest_withdraw_confirm = false;
            } else {
                self.state.show_quest_menu = false;
            }
            return true;
        }
        if self.state.show_loadout_menu {
            self.state.show_loadout_menu = false;
            return true;
        }
        if self.state.show_stats {
            self.state.show_stats = false;
            return true;
        }
        false
    }

    pub fn toggle_stats(&mut self) {
        self.state.show_stats = !self.state.show_stats;
        if self.state.show_stats {
            self.state.show_craft_menu = false;
            self.state.show_shop_menu = false;
            self.state.shop_catalog = None;
            self.state.show_inventory_menu = false;
        }
    }

    pub fn open_inventory_menu(&mut self) {
        self.state.show_inventory_menu = true;
        self.state.show_craft_menu = false;
        self.state.show_shop_menu = false;
        self.state.shop_catalog = None;
        self.state.show_stats = false;
        self.state.show_move_picker = false;
        self.state.move_picker = None;
        self.state.show_destroy_picker = false;
        self.state.destroy_confirm_pending = false;
        self.state.destroy_picker = None;
        self.state.show_rename_prompt = false;
        self.state.rename_buffer.clear();
        self.state.clamp_inventory_indices();
    }

    pub fn close_inventory_menu(&mut self) {
        self.state.show_inventory_menu = false;
        self.state.show_move_picker = false;
        self.state.move_picker = None;
        self.state.show_destroy_picker = false;
        self.state.destroy_confirm_pending = false;
        self.state.destroy_picker = None;
        self.state.show_rename_prompt = false;
        self.state.rename_buffer.clear();
    }

    pub fn open_rename_prompt(&mut self) -> anyhow::Result<()> {
        let Some(row) = self.state.inventory_selected_row() else {
            anyhow::bail!("inventory empty");
        };
        if !self.state.row_is_renameable_container(&row) {
            anyhow::bail!("only storage containers can be renamed");
        }
        let current = row
            .stack
            .display_name
            .clone()
            .unwrap_or_else(|| row.stack.template_id.clone());
        self.state.rename_buffer = current;
        self.state.show_rename_prompt = true;
        self.state.show_move_picker = false;
        self.state.show_destroy_picker = false;
        self.state.destroy_confirm_pending = false;
        Ok(())
    }

    pub fn cancel_rename_prompt(&mut self) {
        self.state.show_rename_prompt = false;
        self.state.rename_buffer.clear();
    }

    pub async fn confirm_rename_prompt(&mut self) -> anyhow::Result<()> {
        let name = self.state.rename_buffer.trim().to_string();
        if name.is_empty() {
            anyhow::bail!("name cannot be empty");
        }
        let Some(row) = self.state.inventory_selected_row() else {
            anyhow::bail!("inventory empty");
        };
        let Some(instance_id) = row.stack.item_instance_id else {
            anyhow::bail!("item has no instance id");
        };
        self.seq += 1;
        self.session
            .submit_intent(Intent::RenameContainer {
                entity_id: self.state.entity_id,
                item_instance_id: instance_id,
                location: row.from.clone(),
                name,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        self.state.show_rename_prompt = false;
        self.state.rename_buffer.clear();
        Ok(())
    }

    pub fn toggle_inventory_menu(&mut self) {
        if self.state.show_inventory_menu {
            self.close_inventory_menu();
        } else {
            self.open_inventory_menu();
        }
    }

    /// ↑/↓ in the inventory browser, or within the "move to…" picker when open.
    pub fn inventory_menu_move(&mut self, delta: i32) {
        if self.state.show_move_picker {
            let n = self
                .state
                .move_picker
                .as_ref()
                .map(|p| p.options.len())
                .unwrap_or(0);
            if n == 0 {
                return;
            }
            let idx = self.state.move_picker_index as i32;
            self.state.move_picker_index = (idx + delta).rem_euclid(n as i32) as usize;
            self.state.clamp_move_picker_quantity();
            return;
        }
        let n = self.state.inventory_selectable_rows().len();
        if n == 0 {
            return;
        }
        let idx = self.state.inventory_menu_index as i32;
        self.state.inventory_menu_index = (idx + delta).rem_euclid(n as i32) as usize;
    }

    /// Enter: unequip a worn bag, equip a weapon, wear/place a loose bag or
    /// chest, drink/eat a loose consumable — or fall back to the "move to…"
    /// destination picker for anything else (including items already inside a
    /// worn bag or a nearby chest).
    pub async fn activate_inventory_selection(&mut self) -> anyhow::Result<()> {
        if self.state.show_destroy_picker {
            if self.state.destroy_confirm_pending {
                return self.confirm_destroy_item().await;
            }
            return self.request_destroy_confirm();
        }
        if self.state.show_move_picker {
            return self.confirm_move_picker().await;
        }
        let Some(row) = self.state.inventory_selected_row() else {
            anyhow::bail!("inventory empty");
        };
        if row.is_equip_shell {
            let flatland_protocol::InventoryLocation::Worn { slot } = row.from else {
                anyhow::bail!("not a worn item");
            };
            return self.equip_worn(slot, None).await;
        }
        if row.is_chest_shell {
            let flatland_protocol::InventoryLocation::Placed { container_id } = row.from else {
                anyhow::bail!("not a placed chest");
            };
            return self.toggle_placed_chest_lock(&container_id).await;
        }
        let template_id = row.stack.template_id.clone();
        let instance_id = row.stack.item_instance_id;
        let category = self.state.inventory_item_category(&template_id);
        let on_person = row.from == flatland_protocol::InventoryLocation::Root;

        if category == Some("weapon") {
            return self.equip_mainhand(Some(template_id)).await;
        }
        if (category == Some("container") || category == Some("armor")) && on_person {
            if let Some(inst) = instance_id {
                if template_id.contains("chest") {
                    return self.place_container(inst).await;
                }
                // Pouches no longer equip directly — they clip onto a worn belt's loops
                // instead, so fall through to the move picker (offers "belt loop" when a
                // belt is worn). Backpacks/belts/armor equip straight to their body slot.
                if let Some(slot) = guess_body_slot(&template_id) {
                    return self.equip_worn(slot, Some(inst)).await;
                }
            }
        }
        if category == Some("consumable") && on_person {
            return self.use_item(&template_id).await;
        }
        // Anything else (materials, pouches, items nested in a bag/chest, weapons
        // you'd rather stash than wield, ...) — offer explicit places to move it
        // instead of guessing.
        self.open_move_picker()
    }

    /// `m`: always open the "move to…" picker for the selected item, even for
    /// weapons/wearables that Enter would otherwise equip/wear directly.
    pub fn open_move_picker(&mut self) -> anyhow::Result<()> {
        let Some(row) = self.state.inventory_selected_row() else {
            anyhow::bail!("inventory empty");
        };
        if row.is_equip_shell {
            anyhow::bail!("this is a worn bag — press Enter to unequip it");
        }
        if row.is_chest_shell {
            anyhow::bail!("select the chest and press Enter or l to lock/unlock it");
        }
        let Some(instance_id) = row.stack.item_instance_id else {
            anyhow::bail!("item has no instance id");
        };
        let options = self.state.move_destinations_for(
            &row.from,
            row.from_parent_instance_id,
            row.stack.item_instance_id,
            &row.stack.template_id,
        );
        let item_label = row
            .stack
            .display_name
            .clone()
            .unwrap_or_else(|| row.stack.template_id.clone());
        self.state.move_picker = Some(MovePicker {
            item_instance_id: instance_id,
            from: row.from,
            item_label,
            template_id: row.stack.template_id.clone(),
            stack_quantity: row.stack.quantity,
            quantity: row.stack.quantity,
            options,
        });
        self.state.move_picker_index = 0;
        self.state.show_move_picker = true;
        self.state.show_destroy_picker = false;
        self.state.destroy_confirm_pending = false;
        self.state.destroy_picker = None;
        Ok(())
    }

    pub fn close_move_picker(&mut self) {
        self.state.show_move_picker = false;
        self.state.move_picker = None;
    }

    pub fn move_picker_adjust_quantity(&mut self, delta: i32) {
        self.state.move_picker_adjust_quantity(delta);
    }

    pub fn move_picker_set_quantity_max(&mut self) {
        self.state.move_picker_set_quantity_max();
    }

    pub fn destroy_picker_adjust_quantity(&mut self, delta: i32) {
        self.state.destroy_picker_adjust_quantity(delta);
    }

    pub fn destroy_picker_set_quantity_max(&mut self) {
        self.state.destroy_picker_set_quantity_max();
    }

    async fn confirm_move_picker(&mut self) -> anyhow::Result<()> {
        let Some(picker) = self.state.move_picker.clone() else {
            self.close_move_picker();
            return Ok(());
        };
        let Some(option) = picker.options.get(self.state.move_picker_index).cloned() else {
            self.close_move_picker();
            return Ok(());
        };
        match option.kind {
            MoveOptionKind::Cancel => {
                self.close_move_picker();
            }
            MoveOptionKind::Drop => {
                self.close_move_picker();
                if let Some(stack) = self.state.stack_for_instance(picker.item_instance_id) {
                    if self.state.key_drop_blocked(&stack) {
                        anyhow::bail!("cannot drop the key while its chest is locked");
                    }
                }
                self.drop_item(picker.item_instance_id, picker.from).await?;
                self.state
                    .push_log(format!("Dropped {}", picker.item_label));
            }
            MoveOptionKind::Move {
                location,
                parent_instance_id,
            } => {
                self.close_move_picker();
                let qty = if picker.quantity >= picker.stack_quantity {
                    None
                } else {
                    Some(picker.quantity)
                };
                self.move_item(
                    picker.item_instance_id,
                    picker.from,
                    location,
                    parent_instance_id,
                    qty,
                )
                .await?;
                let moved = qty.unwrap_or(picker.stack_quantity);
                if moved >= picker.stack_quantity {
                    self.state.push_log(format!("Moved {}", picker.item_label));
                } else {
                    self.state.push_log(format!(
                        "Moved {} ×{} of {}",
                        picker.item_label, moved, picker.stack_quantity
                    ));
                }
            }
        }
        Ok(())
    }

    /// `d`: drop the selected item on the ground immediately (no picker).
    pub async fn drop_selected(&mut self) -> anyhow::Result<()> {
        let Some(row) = self.state.inventory_selected_row() else {
            anyhow::bail!("inventory empty");
        };
        if row.is_equip_shell {
            anyhow::bail!("unequip the bag first (Enter), then drop from your person");
        }
        if row.is_chest_shell {
            anyhow::bail!("can't drop a placed chest from the inventory list — pick it up first");
        }
        let Some(inst) = row.stack.item_instance_id else {
            anyhow::bail!("item has no instance id");
        };
        if self.state.key_drop_blocked(&row.stack) {
            anyhow::bail!("cannot drop the key while its chest is locked");
        }
        let label = row
            .stack
            .display_name
            .clone()
            .unwrap_or_else(|| row.stack.template_id.clone());
        self.drop_item(inst, row.from).await?;
        self.state.push_log(format!("Dropped {label}"));
        Ok(())
    }

    pub async fn drop_item(
        &mut self,
        item_instance_id: uuid::Uuid,
        from: flatland_protocol::InventoryLocation,
    ) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::DropItem {
                entity_id: self.state.entity_id,
                item_instance_id,
                from,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    /// `x`: open permanent-delete picker for the selected item (quantity + confirm).
    pub fn open_destroy_picker(&mut self) -> anyhow::Result<()> {
        let Some(row) = self.state.inventory_selected_row() else {
            anyhow::bail!("inventory empty");
        };
        if row.is_equip_shell {
            anyhow::bail!("unequip the bag first (Enter), then destroy from your person");
        }
        if row.is_chest_shell {
            anyhow::bail!("can't destroy a placed chest from the inventory list");
        }
        let Some(instance_id) = row.stack.item_instance_id else {
            anyhow::bail!("item has no instance id");
        };
        if self.state.key_drop_blocked(&row.stack) {
            anyhow::bail!("cannot destroy the key while its chest is locked");
        }
        let item_label = row
            .stack
            .display_name
            .clone()
            .unwrap_or_else(|| row.stack.template_id.clone());
        self.state.destroy_picker = Some(DestroyPicker {
            item_instance_id: instance_id,
            from: row.from,
            item_label,
            stack_quantity: row.stack.quantity,
            quantity: row.stack.quantity,
        });
        self.state.destroy_confirm_pending = false;
        self.state.show_destroy_picker = true;
        self.state.show_move_picker = false;
        self.state.move_picker = None;
        Ok(())
    }

    pub fn close_destroy_picker(&mut self) {
        self.state.show_destroy_picker = false;
        self.state.destroy_confirm_pending = false;
        self.state.destroy_picker = None;
    }

    pub fn cancel_destroy_confirm(&mut self) {
        self.state.destroy_confirm_pending = false;
    }

    pub fn request_destroy_confirm(&mut self) -> anyhow::Result<()> {
        if self.state.destroy_picker.is_none() {
            self.close_destroy_picker();
            return Ok(());
        }
        self.state.destroy_confirm_pending = true;
        Ok(())
    }

    pub async fn confirm_destroy_item(&mut self) -> anyhow::Result<()> {
        let Some(picker) = self.state.destroy_picker.clone() else {
            self.close_destroy_picker();
            return Ok(());
        };
        let qty = if picker.quantity >= picker.stack_quantity {
            None
        } else {
            Some(picker.quantity)
        };
        self.destroy_item(picker.item_instance_id, picker.from, qty)
            .await?;
        let destroyed = qty.unwrap_or(picker.stack_quantity);
        if destroyed >= picker.stack_quantity {
            self.state
                .push_log(format!("Destroyed {}", picker.item_label));
        } else {
            self.state.push_log(format!(
                "Destroyed {} ×{} of {}",
                picker.item_label, destroyed, picker.stack_quantity
            ));
        }
        self.close_destroy_picker();
        Ok(())
    }

    pub async fn destroy_item(
        &mut self,
        item_instance_id: uuid::Uuid,
        from: flatland_protocol::InventoryLocation,
        quantity: Option<u32>,
    ) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::DestroyItem {
                entity_id: self.state.entity_id,
                item_instance_id,
                from,
                quantity,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    /// `l`: lock/unlock a placed chest — selected chest in inventory UI, else nearest.
    pub async fn toggle_chest_lock_for_selection(&mut self) -> anyhow::Result<()> {
        if let Some(row) = self.state.inventory_selected_row() {
            if let flatland_protocol::InventoryLocation::Placed { container_id } = &row.from {
                return self.toggle_placed_chest_lock(container_id).await;
            }
        }
        self.toggle_nearby_chest_lock().await
    }

    pub async fn toggle_placed_chest_lock(&mut self, container_id: &str) -> anyhow::Result<()> {
        let chest = self
            .state
            .placed_containers
            .iter()
            .find(|c| c.id == container_id)
            .cloned()
            .ok_or_else(|| anyhow::anyhow!("chest not found"))?;
        let (px, py) = self.state.player_position();
        if (chest.x - px).hypot(chest.y - py) > CONTAINER_RANGE_M {
            anyhow::bail!("too far from {}", chest.display_name);
        }
        if !chest.accessible && chest.locked {
            anyhow::bail!(
                "need the matching key for {} (each crafted chest has its own key)",
                chest.display_name
            );
        }
        let lock = !chest.locked;
        self.set_container_locked(
            flatland_protocol::InventoryLocation::Placed {
                container_id: chest.id.clone(),
            },
            lock,
        )
        .await?;
        self.state.push_log(if lock {
            format!("Locked {}", chest.display_name)
        } else {
            format!("Unlocked {}", chest.display_name)
        });
        Ok(())
    }

    /// `l` outside inventory: lock/unlock the nearest placed chest (within `CONTAINER_RANGE_M`).
    pub async fn toggle_nearby_chest_lock(&mut self) -> anyhow::Result<()> {
        let chest = self
            .state
            .nearest_placed_container(CONTAINER_RANGE_M)
            .ok_or_else(|| anyhow::anyhow!("no chest nearby"))?;
        self.toggle_placed_chest_lock(&chest.id).await
    }

    pub async fn unequip_mainhand(&mut self) -> anyhow::Result<()> {
        self.equip_mainhand(None).await
    }

    pub async fn unequip_all_worn(&mut self) -> anyhow::Result<()> {
        let slots: Vec<BodySlot> = self.state.worn.keys().copied().collect();
        for slot in slots {
            self.equip_worn(slot, None).await?;
        }
        Ok(())
    }

    pub async fn pickup_nearest_container(&mut self) -> anyhow::Result<()> {
        let (px, py) = self.state.player_position();
        let nearest = self
            .state
            .placed_containers
            .iter()
            .min_by(|a, b| {
                let da = (a.x - px).hypot(a.y - py);
                let db = (b.x - px).hypot(b.y - py);
                da.partial_cmp(&db).unwrap_or(std::cmp::Ordering::Equal)
            })
            .cloned();
        let Some(chest) = nearest else {
            anyhow::bail!("no chest nearby");
        };
        if (chest.x - px).hypot(chest.y - py) > 2.0 {
            anyhow::bail!("too far from chest");
        }
        self.pickup_container(chest.id).await
    }

    pub async fn equip_worn(
        &mut self,
        slot: BodySlot,
        instance_id: Option<uuid::Uuid>,
    ) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::EquipWorn {
                entity_id: self.state.entity_id,
                slot,
                instance_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn place_container(&mut self, item_instance_id: uuid::Uuid) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::PlaceContainer {
                entity_id: self.state.entity_id,
                item_instance_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn pickup_container(&mut self, container_id: String) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::PickupContainer {
                entity_id: self.state.entity_id,
                container_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn move_item(
        &mut self,
        item_instance_id: uuid::Uuid,
        from: flatland_protocol::InventoryLocation,
        to: flatland_protocol::InventoryLocation,
        to_parent_instance_id: Option<uuid::Uuid>,
        quantity: Option<u32>,
    ) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::MoveItem {
                entity_id: self.state.entity_id,
                item_instance_id,
                from,
                to,
                to_parent_instance_id,
                quantity,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn set_container_locked(
        &mut self,
        location: flatland_protocol::InventoryLocation,
        locked: bool,
    ) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::SetContainerLocked {
                entity_id: self.state.entity_id,
                location,
                locked,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn use_item(&mut self, template_id: &str) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::Use {
                entity_id: self.state.entity_id,
                template_id: template_id.to_string(),
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub fn open_craft_menu(&mut self) {
        self.state.show_craft_menu = true;
        self.state.show_shop_menu = false;
        self.state.shop_catalog = None;
        self.state.show_stats = false;
        self.state.show_inventory_menu = false;
        if self.state.blueprints.is_empty() {
            self.state.craft_menu_index = 0;
            self.state.craft_batch_quantity = 1;
            return;
        }
        self.state.craft_menu_index = self
            .state
            .craft_menu_index
            .min(self.state.blueprints.len() - 1);
        if let Some(idx) = self
            .state
            .blueprints
            .iter()
            .position(|bp| self.state.can_craft_blueprint(bp))
        {
            self.state.craft_menu_index = idx;
        }
        self.state.clamp_craft_batch_quantity();
    }

    pub fn close_craft_menu(&mut self) {
        self.state.show_craft_menu = false;
    }

    pub fn toggle_keychain_menu(&mut self) {
        if self.state.show_keychain_menu {
            self.close_keychain_menu();
        } else {
            self.state.show_keychain_menu = true;
            self.state.show_craft_menu = false;
            self.state.show_shop_menu = false;
            self.state.show_inventory_menu = false;
            let n = self.state.keychain_entries().len();
            if n == 0 {
                self.state.keychain_menu_index = 0;
            } else {
                self.state.keychain_menu_index = self.state.keychain_menu_index.min(n - 1);
            }
        }
    }

    pub fn close_keychain_menu(&mut self) {
        self.state.show_keychain_menu = false;
    }

    pub fn keychain_menu_move(&mut self, delta: i32) {
        let n = self.state.keychain_entries().len();
        if n == 0 {
            self.state.keychain_menu_index = 0;
            return;
        }
        let idx = self.state.keychain_menu_index as i32 + delta;
        self.state.keychain_menu_index = idx.rem_euclid(n as i32) as usize;
    }

    pub async fn activate_keychain_selection(&mut self) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let entries = self.state.keychain_entries();
        let Some(entry) = entries.get(self.state.keychain_menu_index) else {
            anyhow::bail!("nothing selected");
        };
        let Some(instance_id) = entry.stack.item_instance_id else {
            anyhow::bail!("key has no instance id");
        };
        if entry.stowed {
            self.move_item(
                instance_id,
                flatland_protocol::InventoryLocation::Keychain,
                flatland_protocol::InventoryLocation::Root,
                None,
                Some(1),
            )
            .await
        } else {
            self.move_item(
                instance_id,
                flatland_protocol::InventoryLocation::Root,
                flatland_protocol::InventoryLocation::Keychain,
                None,
                Some(1),
            )
            .await
        }
    }

    pub fn close_shop_menu(&mut self) {
        self.state.show_shop_menu = false;
        self.state.shop_catalog = None;
        self.state.clear_shop_trade_log();
    }

    pub fn shop_tab_toggle(&mut self) {
        self.state.shop_tab = match self.state.shop_tab {
            ShopTab::Buy => ShopTab::Sell,
            ShopTab::Sell => ShopTab::Buy,
        };
        self.state.shop_menu_index = 0;
        self.state.clamp_shop_selection();
    }

    pub fn shop_menu_move(&mut self, delta: i32) {
        self.state.shop_menu_move(delta);
    }

    pub fn shop_quantity_adjust(&mut self, delta: i32) {
        self.state.shop_quantity_adjust(delta);
    }

    pub fn shop_quantity_set_max(&mut self) {
        self.state.shop_quantity_set_max();
    }

    pub fn toggle_quest_menu(&mut self) {
        self.state.show_quest_menu = !self.state.show_quest_menu;
        if self.state.show_quest_menu {
            self.state.quest_menu_index = 0;
            self.state.quest_withdraw_confirm = false;
        }
    }

    pub fn quest_menu_move(&mut self, delta: i32) {
        let n = self.state.active_quest_entries().len();
        if n == 0 {
            return;
        }
        let idx = self.state.quest_menu_index as i32;
        self.state.quest_menu_index = (idx + delta).rem_euclid(n as i32) as usize;
    }

    pub async fn quest_offer_accept(&mut self) -> anyhow::Result<()> {
        let Some(offer) = self.state.pending_quest_offer.clone() else {
            anyhow::bail!("no quest offer");
        };
        self.seq += 1;
        let seq = self.seq;
        self.session
            .submit_intent(Intent::AcceptQuest {
                entity_id: self.state.entity_id,
                quest_id: offer.quest_id,
                seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub fn quest_offer_decline(&mut self) {
        self.state.show_quest_offer = false;
        self.state.pending_quest_offer = None;
    }

    pub async fn quest_confirm_action(&mut self) -> anyhow::Result<()> {
        if !self.state.show_quest_menu {
            return Ok(());
        }
        let active: Vec<_> = self
            .state
            .active_quest_entries()
            .into_iter()
            .cloned()
            .collect();
        let Some(entry) = active.get(self.state.quest_menu_index) else {
            return Ok(());
        };
        if self.state.quest_withdraw_confirm {
            if !entry.can_withdraw {
                anyhow::bail!("quest cannot be withdrawn");
            }
            self.seq += 1;
            let seq = self.seq;
            self.session
                .submit_intent(Intent::WithdrawQuest {
                    entity_id: self.state.entity_id,
                    quest_id: entry.quest_id.clone(),
                    seq,
                })
                .await?;
            self.state.intents_sent += 1;
            self.state.quest_withdraw_confirm = false;
            return Ok(());
        }
        self.seq += 1;
        let seq = self.seq;
        self.session
            .submit_intent(Intent::TrackQuest {
                entity_id: self.state.entity_id,
                quest_id: entry.quest_id.clone(),
                seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub fn quest_request_withdraw(&mut self) {
        if self.state.show_quest_menu {
            self.state.quest_withdraw_confirm = true;
        }
    }

    pub async fn shop_confirm(&mut self) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let Some(catalog) = self.state.shop_catalog.clone() else {
            anyhow::bail!("no shop open");
        };
        self.seq += 1;
        let seq = self.seq;
        match self.state.shop_tab {
            ShopTab::Buy => {
                let Some(offer) = catalog.sells.get(self.state.shop_menu_index) else {
                    anyhow::bail!("nothing selected");
                };
                if offer.already_owned {
                    anyhow::bail!("already owned");
                }
                self.session
                    .submit_intent(Intent::ShopBuy {
                        entity_id: self.state.entity_id,
                        npc_id: catalog.npc_id.clone(),
                        offer_id: offer.offer_id.clone(),
                        quantity: self.state.shop_quantity,
                        seq,
                    })
                    .await?;
            }
            ShopTab::Sell => {
                let Some(line) = catalog.buys.get(self.state.shop_menu_index) else {
                    anyhow::bail!("nothing to sell");
                };
                self.session
                    .submit_intent(Intent::ShopSell {
                        entity_id: self.state.entity_id,
                        npc_id: catalog.npc_id.clone(),
                        template_id: line.template_id.clone(),
                        quantity: self.state.shop_quantity.min(line.quantity),
                        seq,
                    })
                    .await?;
            }
        }
        self.state.intents_sent += 1;
        Ok(())
    }

    pub fn craft_menu_move(&mut self, delta: i32) {
        let n = self.state.blueprints.len();
        if n == 0 {
            return;
        }
        let idx = self.state.craft_menu_index as i32;
        let next = (idx + delta).rem_euclid(n as i32);
        self.state.craft_menu_index = next as usize;
        self.state.clamp_craft_batch_quantity();
    }

    pub fn craft_batch_adjust_quantity(&mut self, delta: i32) {
        self.state.craft_batch_adjust_quantity(delta);
    }

    pub fn craft_batch_set_max(&mut self) {
        self.state.craft_batch_set_max();
    }

    pub async fn craft_menu_selection(&mut self) -> anyhow::Result<()> {
        let Some(blueprint) = self
            .state
            .blueprints
            .get(self.state.craft_menu_index)
            .cloned()
        else {
            anyhow::bail!("no blueprints known");
        };
        if !self.state.can_craft_blueprint(&blueprint) {
            let hint = self
                .state
                .craft_missing_hint(&blueprint)
                .unwrap_or_else(|| "missing materials".into());
            anyhow::bail!("cannot craft {}: {hint}", blueprint.label);
        }
        let count = self.state.craft_batch_quantity;
        let max = self.state.max_craft_batches(&blueprint);
        if max == 0 {
            anyhow::bail!("cannot craft {}", blueprint.label);
        }
        let batches = count.min(max);
        self.craft(&blueprint.id, Some(batches)).await?;
        self.state.show_craft_menu = false;
        Ok(())
    }

    pub async fn move_by(
        &mut self,
        forward: f32,
        strafe: f32,
        vertical: f32,
        sprint: bool,
    ) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        if forward.abs() > f32::EPSILON || strafe.abs() > f32::EPSILON {
            self.last_move_forward = forward;
            self.last_move_strafe = strafe;
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::Move {
                entity_id: self.state.entity_id,
                forward,
                strafe,
                vertical,
                sprint,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn harvest_nearest(&mut self) -> anyhow::Result<()> {
        if !self.state.connected {
            crate::harvest_trace!("harvest_nearest rejected: not connected");
            anyhow::bail!("not connected");
        }
        if !self.state.is_alive() {
            crate::harvest_trace!("harvest_nearest rejected: player dead");
            anyhow::bail!("you are dead");
        }
        if self.state.harvest_in_progress {
            if self.state.harvest_state_stale() {
                self.state.clear_harvest_state();
            } else {
                anyhow::bail!("already harvesting");
            }
        }
        let (px, py) = self
            .state
            .player
            .as_ref()
            .map(|p| (p.transform.position.x, p.transform.position.y))
            .unwrap_or((0.0, 0.0));

        let available = self
            .state
            .resource_nodes
            .iter()
            .filter(|n| n.state == flatland_protocol::ResourceNodeState::Available)
            .count();
        let node_id = self
            .state
            .resource_nodes
            .iter()
            .filter(|n| n.state == flatland_protocol::ResourceNodeState::Available)
            .filter(|n| distance(px, py, n.x, n.y) <= HARVEST_RANGE_M)
            .min_by(|a, b| {
                let da = distance(px, py, a.x, a.y);
                let db = distance(px, py, b.x, b.y);
                da.partial_cmp(&db).unwrap_or(std::cmp::Ordering::Equal)
            })
            .map(|n| n.id.clone());

        let Some(node_id) = node_id else {
            let has_loot = self
                .state
                .ground_drops
                .iter()
                .any(|d| distance(px, py, d.x, d.y) <= INTERACTION_RADIUS_M);
            if has_loot {
                return self.pickup_nearest().await;
            }
            anyhow::bail!(
                "no harvestable nodes within {HARVEST_RANGE_M}m — stand on * loot and press f to pick up"
            );
        };

        self.seq += 1;
        let seq = self.seq;
        crate::harvest_trace!(
            entity_id = self.state.entity_id,
            node_id = %node_id,
            seq,
            px,
            py,
            available_nodes = available,
            "submitting harvest intent"
        );
        self.session
            .submit_intent(Intent::Harvest {
                entity_id: self.state.entity_id,
                node_id,
                seq,
            })
            .await?;
        self.state.intents_sent += 1;
        self.state.harvest_in_progress = true;
        self.state.harvest_started_at = Some(Instant::now());
        self.state.push_log("Harvesting…");
        crate::harvest_trace!(
            entity_id = self.state.entity_id,
            seq,
            "harvest intent queued to session"
        );
        Ok(())
    }

    pub async fn craft_next_available(&mut self) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let blueprint_id = self
            .state
            .blueprints
            .iter()
            .find(|bp| self.state.can_craft_blueprint(bp))
            .map(|bp| bp.id.clone())
            .ok_or_else(|| anyhow::anyhow!("no craftable blueprint (need materials)"))?;
        self.craft(&blueprint_id, None).await
    }

    pub async fn craft(&mut self, blueprint_id: &str, count: Option<u32>) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::Craft {
                entity_id: self.state.entity_id,
                blueprint_id: blueprint_id.to_string(),
                count,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        let (label, batches) = self
            .state
            .blueprints
            .iter()
            .find(|b| b.id == blueprint_id)
            .map(|b| {
                let n = count.unwrap_or_else(|| self.state.max_craft_batches(b).max(1));
                (b.label.as_str(), n)
            })
            .unwrap_or((blueprint_id, count.unwrap_or(1)));
        self.state.pending_craft_ack = Some((self.seq, label.to_string(), batches));
        Ok(())
    }

    pub async fn interact_nearest(&mut self) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let target_id = match self.state.nearest_interact_target() {
            Some(id) => id,
            None => {
                anyhow::bail!("nothing to interact with nearby");
            }
        };
        if self.state.npcs.iter().any(|n| n.id == target_id) {
            self.state.show_npc_verb_menu = true;
            self.state.npc_verb_target = Some(target_id);
            self.state.npc_verb_index = 0;
            return Ok(());
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::Interact {
                entity_id: self.state.entity_id,
                target_id: target_id.clone(),
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    /// Context-sensitive world use: interact → pickup loot/chest → harvest/butcher.
    pub async fn use_nearest(&mut self) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        if self.state.nearest_interact_target().is_some() {
            return self.interact_nearest().await;
        }
        // Prefer a clear "move closer" when a board is visible but out of reach,
        // instead of silently falling through to harvest.
        if let Some((label, dist)) = self.state.nearest_quest_board() {
            if dist > QUEST_BOARD_INTERACTION_RADIUS_M && dist <= NEARBY_SCAN_M {
                anyhow::bail!(
                    "too far from {label} ({dist:.1}m) — move within {QUEST_BOARD_INTERACTION_RADIUS_M}m and press f"
                );
            }
        }
        let (px, py) = self.state.player_position();
        let has_loot = self
            .state
            .ground_drops
            .iter()
            .any(|d| distance(px, py, d.x, d.y) <= INTERACTION_RADIUS_M);
        if has_loot {
            return self.pickup_nearest().await;
        }
        if self
            .state
            .placed_containers
            .iter()
            .any(|c| (c.x - px).hypot(c.y - py) <= 2.0)
        {
            return self.pickup_nearest_container().await;
        }
        match self.harvest_nearest().await {
            Ok(()) => Ok(()),
            Err(err) => {
                let msg = err.to_string();
                if msg.contains("no harvestable")
                    || msg.contains("press p")
                    || msg.contains("press f")
                {
                    anyhow::bail!(
                        "nothing to use nearby — stand by an NPC/door, loot (*), chest, or resource"
                    );
                }
                Err(err)
            }
        }
    }

    /// Cast a hotbar-bound ability (`1`–`9`). Heals prefer T2/self; others prefer T1.
    pub async fn cast_hotbar_ability(&mut self, ability_id: &str) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let target = if ability_id == "heal_touch" {
            Some(
                self.state
                    .target_for_slot(2)
                    .unwrap_or(self.state.entity_id),
            )
        } else {
            self.state
                .target_for_slot(1)
                .or_else(|| self.state.target_for_slot(2))
        };
        let Some(target_id) = target else {
            anyhow::bail!("no target — Tab to select, then press the hotbar key");
        };
        self.cast_ability(ability_id, Some(target_id)).await
    }

    pub fn npc_verb_options(&self) -> Vec<&'static str> {
        self.state.npc_verb_options()
    }

    pub async fn confirm_npc_verb(&mut self) -> anyhow::Result<()> {
        let Some(npc_id) = self.state.npc_verb_target.clone() else {
            return Ok(());
        };
        let options = self.npc_verb_options();
        let choice = options
            .get(self.state.npc_verb_index)
            .copied()
            .unwrap_or("Talk");
        self.state.show_npc_verb_menu = false;
        self.state.npc_verb_target = None;
        self.seq += 1;
        match choice {
            "Trade" => {
                self.session
                    .submit_intent(Intent::Interact {
                        entity_id: self.state.entity_id,
                        target_id: npc_id,
                        seq: self.seq,
                    })
                    .await?;
            }
            _ => {
                self.session
                    .submit_intent(Intent::NpcTalkOpen {
                        entity_id: self.state.entity_id,
                        npc_id,
                        seq: self.seq,
                    })
                    .await?;
            }
        }
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn npc_talk_send(&mut self) -> anyhow::Result<()> {
        let Some(chat) = self.state.npc_chat.clone() else {
            return Ok(());
        };
        let message = chat.input.trim().to_string();
        if message.is_empty() || chat.pending {
            return Ok(());
        }
        if let Some(c) = self.state.npc_chat.as_mut() {
            c.lines.push(format!("You: {message}"));
            c.input.clear();
            c.pending = true;
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::NpcTalkSay {
                entity_id: self.state.entity_id,
                npc_id: chat.npc_id,
                message,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn npc_talk_close(&mut self) -> anyhow::Result<()> {
        let Some(npc_id) = self.state.npc_chat.as_ref().map(|c| c.npc_id.clone()) else {
            self.state.show_npc_chat = false;
            return Ok(());
        };
        self.seq += 1;
        self.session
            .submit_intent(Intent::NpcTalkClose {
                entity_id: self.state.entity_id,
                npc_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        self.state.show_npc_chat = false;
        self.state.npc_chat = None;
        Ok(())
    }

    pub async fn test_damage(&mut self, amount: f32) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::TestDamage {
                entity_id: self.state.entity_id,
                amount,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn cycle_combat_target(&mut self, reverse: bool) -> anyhow::Result<()> {
        self.cycle_combat_target_slot(1, reverse).await
    }

    pub async fn cycle_combat_target_slot(
        &mut self,
        slot_index: u8,
        reverse: bool,
    ) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let candidates = self.state.candidates_for_slot(slot_index);
        if candidates.is_empty() {
            anyhow::bail!("no targets nearby");
        }
        let current = self.state.target_for_slot(slot_index);
        let idx = current.and_then(|id| candidates.iter().position(|(eid, _)| *eid == id));
        let next_idx = match idx {
            None => 0,
            Some(i) if reverse => {
                if i == 0 {
                    candidates.len() - 1
                } else {
                    i - 1
                }
            }
            Some(i) => (i + 1) % candidates.len(),
        };
        if idx == Some(next_idx) && candidates.len() == 1 {
            self.clear_combat_target_slot(slot_index).await?;
            return Ok(());
        }
        let (target_id, label) = candidates[next_idx].clone();
        self.set_combat_target_slot(slot_index, target_id, &label)
            .await
    }

    pub async fn set_combat_target_slot(
        &mut self,
        slot_index: u8,
        target_id: EntityId,
        label: &str,
    ) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::SetTargetSlot {
                entity_id: self.state.entity_id,
                slot_index,
                target_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        if slot_index == 1 {
            self.state.combat_target = Some(target_id);
            self.state.combat_target_label = Some(label.to_string());
        }
        self.state
            .push_log(format!("Slot {slot_index} target: {label}"));
        Ok(())
    }

    pub async fn set_combat_target(
        &mut self,
        target_id: EntityId,
        label: &str,
    ) -> anyhow::Result<()> {
        self.set_combat_target_slot(1, target_id, label).await
    }

    pub async fn clear_combat_target_slot(&mut self, slot_index: u8) -> anyhow::Result<()> {
        if slot_index == 1 && self.state.combat_target.is_none() {
            return Ok(());
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::ClearTargetSlot {
                entity_id: self.state.entity_id,
                slot_index,
                seq: self.seq,
            })
            .await?;
        if slot_index == 1 {
            self.state.combat_target = None;
            self.state.combat_target_label = None;
        }
        self.state.intents_sent += 1;
        self.state
            .push_log(format!("Slot {slot_index} target cleared"));
        Ok(())
    }

    pub async fn clear_combat_target(&mut self) -> anyhow::Result<()> {
        self.clear_combat_target_slot(1).await
    }

    pub async fn advance_rotation(&mut self, slot_index: u8) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::AdvanceRotation {
                entity_id: self.state.entity_id,
                slot_index,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn assign_slot_preset(
        &mut self,
        slot_index: u8,
        preset_id: &str,
    ) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::AssignSlotPreset {
                entity_id: self.state.entity_id,
                slot_index,
                preset_id: preset_id.to_string(),
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        if let Some(slot) = self
            .state
            .combat_slots
            .iter_mut()
            .find(|s| s.slot_index == slot_index)
        {
            slot.preset_id = Some(preset_id.to_string());
            if let Some(preset) = self
                .state
                .rotation_presets
                .iter()
                .find(|p| p.id == preset_id)
            {
                slot.preset_label = Some(preset.label.clone());
                slot.rotation = preset.abilities.clone();
                slot.rotation_index = 0;
            }
        }
        self.state
            .push_log(format!("T{slot_index} loadout → {preset_id}"));
        Ok(())
    }

    pub async fn cast_ability(
        &mut self,
        ability_id: &str,
        target_id: Option<EntityId>,
    ) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let target_id = target_id
            .or_else(|| self.state.target_for_slot(2))
            .or_else(|| self.state.target_for_slot(1))
            .unwrap_or(self.state.entity_id);
        self.seq += 1;
        self.session
            .submit_intent(Intent::Cast {
                entity_id: self.state.entity_id,
                ability_id: ability_id.to_string(),
                target_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        self.state
            .push_log(format!("Cast {ability_id} → {target_id}"));
        Ok(())
    }

    pub async fn upsert_rotation_preset(&mut self, preset: RotationPreset) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::UpsertRotationPreset {
                entity_id: self.state.entity_id,
                preset: preset.clone(),
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        if let Some(existing) = self
            .state
            .rotation_presets
            .iter_mut()
            .find(|p| p.id == preset.id)
        {
            *existing = preset.clone();
        } else {
            self.state.rotation_presets.push(preset.clone());
        }
        for slot in &mut self.state.combat_slots {
            if slot.preset_id.as_deref() == Some(preset.id.as_str()) {
                slot.preset_label = Some(preset.label.clone());
                slot.rotation = preset.abilities.clone();
            }
        }
        self.state
            .push_log(format!("Saved rotation: {}", preset.label));
        Ok(())
    }

    pub async fn delete_rotation_preset(&mut self, preset_id: &str) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::DeleteRotationPreset {
                entity_id: self.state.entity_id,
                preset_id: preset_id.to_string(),
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        self.state.rotation_presets.retain(|p| p.id != preset_id);
        for slot in &mut self.state.combat_slots {
            if slot.preset_id.as_deref() == Some(preset_id) {
                slot.preset_id = None;
                slot.preset_label = None;
                slot.rotation.clear();
                slot.rotation_index = 0;
            }
        }
        self.state
            .push_log(format!("Deleted rotation: {preset_id}"));
        Ok(())
    }

    pub async fn toggle_auto_attack_slot(&mut self, slot_index: u8) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let enabled = !self
            .state
            .combat_slots
            .iter()
            .find(|s| s.slot_index == slot_index)
            .map(|s| s.auto_enabled)
            .unwrap_or(false);
        self.seq += 1;
        self.session
            .submit_intent(Intent::SetAutoAttack {
                entity_id: self.state.entity_id,
                slot_index,
                enabled,
                seq: self.seq,
            })
            .await?;
        if slot_index == 1 {
            self.state.auto_attack = enabled;
        }
        self.state.intents_sent += 1;
        self.state.push_log(format!(
            "T{slot_index} auto {}",
            if enabled { "ON" } else { "OFF" }
        ));
        Ok(())
    }

    pub async fn pickup_nearest(&mut self) -> anyhow::Result<()> {
        if !self.state.connected {
            anyhow::bail!("not connected");
        }
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let (px, py) = self.state.player_position();
        if self
            .state
            .ground_drops
            .iter()
            .all(|d| distance(px, py, d.x, d.y) > INTERACTION_RADIUS_M)
        {
            anyhow::bail!("no loot within {INTERACTION_RADIUS_M}m — walk onto the * and press f");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::Pickup {
                entity_id: self.state.entity_id,
                drop_id: None,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn toggle_auto_attack(&mut self) -> anyhow::Result<()> {
        self.toggle_auto_attack_slot(1).await
    }

    pub async fn dodge(&mut self) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::Dodge {
                entity_id: self.state.entity_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        self.state.push_log("Dodge!");
        Ok(())
    }

    pub async fn lunge(&mut self) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        let (forward, strafe) = self.last_move_axes();
        self.seq += 1;
        self.session
            .submit_intent(Intent::Lunge {
                entity_id: self.state.entity_id,
                forward,
                strafe,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        self.state.push_log("Lunge!");
        Ok(())
    }

    /// Remembered WASD axes for lunge when not currently moving.
    pub fn last_move_axes(&self) -> (f32, f32) {
        (self.last_move_forward, self.last_move_strafe)
    }

    pub async fn set_block(&mut self, enabled: bool) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::Block {
                entity_id: self.state.entity_id,
                enabled,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        if enabled {
            self.state.push_log("Blocking");
        }
        Ok(())
    }

    pub async fn equip_mainhand(&mut self, template_id: Option<String>) -> anyhow::Result<()> {
        if !self.state.is_alive() {
            anyhow::bail!("you are dead");
        }
        self.seq += 1;
        self.session
            .submit_intent(Intent::EquipMainhand {
                entity_id: self.state.entity_id,
                template_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn say(
        &mut self,
        channel: flatland_protocol::ChatChannel,
        text: &str,
    ) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::Say {
                entity_id: self.state.entity_id,
                channel,
                text: text.to_string(),
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub async fn stop(&mut self) -> anyhow::Result<()> {
        self.seq += 1;
        self.session
            .submit_intent(Intent::Stop {
                entity_id: self.state.entity_id,
                seq: self.seq,
            })
            .await?;
        self.state.intents_sent += 1;
        Ok(())
    }

    pub fn disconnect(&self) {
        self.session.disconnect();
    }
}

fn distance(ax: f32, ay: f32, bx: f32, by: f32) -> f32 {
    let dx = ax - bx;
    let dy = ay - by;
    (dx * dx + dy * dy).sqrt()
}

#[cfg(test)]
mod tests {
    use std::collections::BTreeMap;

    use super::*;
    use flatland_protocol::{
        BuildingView, ResourceNodeState, ResourceNodeView, TickDelta, Transform, WorldCoord,
    };

    fn sample_state() -> GameState {
        let mut state = GameState {
            session_id: 1,
            entity_id: 1,
            character_id: None,
            tick: 0,
            chunk_rev: 0,
            content_rev: 0,
            entities: vec![EntityState {
                id: 1,
                label: "You".into(),
                transform: Transform {
                    position: WorldCoord::surface(128.0, 128.0),
                    yaw: 0.0,
                    velocity: flatland_protocol::Velocity2D { vx: 0.0, vy: 0.0 },
                },
                vitals: None,
                attributes: None,
                skills: None,
                inside_building: None,
                tile_id: None,
                presentation_state: None,
                sprite_mode: None,
                progression_xp: None,
            }],
            player: None,
            resource_nodes: vec![ResourceNodeView {
                id: "oak-1".into(),
                label: "Oak".into(),
                x: 130.0,
                y: 128.0,
                z: 0.0,
                item_template: "oak_log".into(),
                state: ResourceNodeState::Available,
                blocking: true,
                blocking_radius_m: 0.8,
                tile_id: None,
                sprite_mode: None,
                presentation_state: None,
            }],
            ground_drops: vec![],
            placed_containers: vec![],
            buildings: vec![BuildingView {
                id: "broker-hut".into(),
                label: "Broker".into(),
                x: 148.0,
                y: 118.0,
                width_m: 8.0,
                depth_m: 6.0,
                interior_blueprint: Some("broker_hut".into()),
                tags: vec![],
            }],
            doors: vec![flatland_protocol::DoorView {
                id: "door-1".into(),
                building_id: "broker-hut".into(),
                x: 148.0,
                y: 118.0,
                open: false,
                portal: Some("front".into()),
            }],
            interior_map: None,
            npcs: vec![],
            blueprints: vec![],
            world_width_m: 256.0,
            world_height_m: 256.0,
            terrain_zones: Vec::new(),
            z_platforms: Vec::new(),
            z_transitions: Vec::new(),
            world_clock: flatland_protocol::WorldClock::default(),
            inventory: std::collections::HashMap::new(),
            inventory_hints: std::collections::HashMap::new(),
            logs: VecDeque::new(),
            intents_sent: 0,
            ticks_received: 0,
            connected: true,
            disconnect_reason: None,
            show_stats: false,
            show_craft_menu: false,
            craft_menu_index: 0,
            craft_batch_quantity: 1,
            show_shop_menu: false,
            shop_catalog: None,
            shop_tab: ShopTab::default(),
            shop_menu_index: 0,
            shop_quantity: 1,
            shop_trade_log: VecDeque::new(),
            show_npc_verb_menu: false,
            npc_verb_target: None,
            npc_verb_index: 0,
            show_npc_chat: false,
            npc_chat: None,
            show_inventory_menu: false,
            inventory_menu_index: 0,
            show_move_picker: false,
            show_rename_prompt: false,
            rename_buffer: String::new(),
            move_picker_index: 0,
            move_picker: None,
            show_destroy_picker: false,
            destroy_confirm_pending: false,
            destroy_picker: None,
            combat_target: None,
            combat_target_label: None,
            in_combat: false,
            auto_attack: true,
            combat_has_los: false,
            attack_cd_ticks: 0,
            gcd_ticks: 0,
            weapon_ability_id: "unarmed".into(),
            mainhand_template_id: None,
            mainhand_label: None,
            worn: BTreeMap::new(),
            carry_mass: 0.0,
            carry_mass_max: 0.0,
            encumbrance: flatland_protocol::EncumbranceState::Light,
            inventory_stacks: Vec::new(),
            keychain_stacks: Vec::new(),
            combat_target_detail: None,
            cast_progress: None,
            ability_cooldowns: Vec::new(),
            blocking_active: false,
            max_target_slots: 1,
            combat_slots: Vec::new(),
            rotation_presets: Vec::new(),
            show_loadout_menu: false,
            show_keychain_menu: false,
            keychain_menu_index: 0,
            show_rotation_editor: false,
            loadout_menu_index: 0,
            rotation_editor: RotationEditorState::default(),
            harvest_in_progress: false,
            harvest_started_at: None,
            pending_craft_ack: None,
            quest_log: Vec::new(),
            interactables: Vec::new(),
            show_quest_offer: false,
            pending_quest_offer: None,
            show_quest_menu: false,
            quest_menu_index: 0,
            quest_withdraw_confirm: false,
            progression_curve: None,
        };
        state.player = state.entities.first().cloned();
        state
    }

    #[test]
    fn probe_use_world_npc_beats_nearby_loot() {
        let mut state = sample_state();
        state.npcs.push(flatland_protocol::NpcView {
            id: "ada".into(),
            label: "Ada".into(),
            role: "broker".into(),
            x: 129.0,
            y: 128.0,
            building_id: None,
            entity_id: None,
            life_state: None,
            hp_pct: None,
            can_trade: true,
            tile_id: None,
            behavior_state: None,
            presentation_state: None,
            sprite_mode: None,
        });
        state.ground_drops.push(flatland_protocol::GroundDropView {
            id: "d1".into(),
            template_id: "lumber".into(),
            quantity: 1,
            x: 128.5,
            y: 128.0,
            z: 0.0,
            tile_id: None,
        });
        let probe = state.probe_use_world();
        let primary = probe.primary.expect("primary");
        assert_eq!(primary.kind, crate::UseWorldKind::Npc);
        assert_eq!(primary.id, "ada");
    }

    #[test]
    fn probe_use_world_harvest_when_in_range() {
        let state = sample_state(); // oak at 130,128 — player 128,128 → dist 2 > 1.5
        let probe = state.probe_use_world();
        assert!(
            probe.primary.is_none(),
            "oak is 2m away, out of harvest range"
        );
        assert!(probe
            .candidates
            .iter()
            .any(|c| c.kind == crate::UseWorldKind::Harvest));

        let mut state = sample_state();
        state.resource_nodes[0].x = 129.0;
        let probe = state.probe_use_world();
        let primary = probe.primary.expect("primary");
        assert_eq!(primary.kind, crate::UseWorldKind::Harvest);
    }

    #[test]
    fn empty_entity_tick_preserves_welcome_snapshot() {
        let mut state = sample_state();
        state.inventory.insert("carrot".into(), 3);
        let delta = TickDelta {
            tick: 1,
            entities: vec![],
            resource_nodes: vec![],
            ground_drops: vec![],
            placed_containers: vec![],
            buildings: vec![],
            doors: vec![],
            interior_map: None,
            npcs: vec![],
            inventory: vec![],
            blueprints: vec![],
            world_clock: flatland_protocol::WorldClock::default(),
            combat: None,
            quest_log: vec![],
            interactables: vec![],
        };

        state.apply_tick_fields(&delta, 1);

        assert_eq!(state.entities.len(), 1);
        assert!(state.player.is_some());
        assert_eq!(state.inventory.get("carrot"), Some(&3));
        assert_eq!(state.resource_nodes.len(), 1);
    }

    #[test]
    fn tick_preserves_world_layers_when_delta_omits_them() {
        let mut state = sample_state();
        let delta = TickDelta {
            tick: 1,
            entities: state.entities.clone(),
            resource_nodes: vec![],
            ground_drops: vec![],
            placed_containers: vec![],
            buildings: vec![],
            doors: vec![],
            interior_map: None,
            npcs: vec![],
            inventory: vec![],
            blueprints: vec![],
            world_clock: flatland_protocol::WorldClock::default(),
            combat: None,
            quest_log: vec![],
            interactables: vec![],
        };

        state.apply_tick_fields(&delta, 1);

        assert_eq!(state.resource_nodes.len(), 1);
        assert_eq!(state.buildings.len(), 1);
        assert_eq!(state.doors.len(), 1);
    }

    #[test]
    fn tick_updates_resource_nodes_when_server_sends_them() {
        let mut state = sample_state();
        let delta = TickDelta {
            tick: 1,
            entities: state.entities.clone(),
            resource_nodes: vec![ResourceNodeView {
                id: "oak-1".into(),
                label: "Oak".into(),
                x: 130.0,
                y: 128.0,
                z: 0.0,
                item_template: "oak_log".into(),
                state: ResourceNodeState::Cooldown,
                blocking: true,
                blocking_radius_m: 0.8,
                tile_id: None,
                sprite_mode: None,
                presentation_state: None,
            }],
            buildings: vec![],
            doors: vec![],
            interior_map: None,
            npcs: vec![],
            inventory: vec![],
            blueprints: vec![],
            world_clock: flatland_protocol::WorldClock::default(),
            ground_drops: vec![],
            placed_containers: vec![],
            combat: None,
            quest_log: vec![],
            interactables: vec![],
        };

        state.apply_tick_fields(&delta, 1);

        assert!(matches!(
            state.resource_nodes[0].state,
            ResourceNodeState::Cooldown
        ));
    }

    #[test]
    fn interact_prefers_npc_over_interior_exit_at_entry_spawn() {
        let mut state = GameState {
            session_id: 1,
            entity_id: 1,
            character_id: None,
            tick: 0,
            chunk_rev: 0,
            content_rev: 0,
            entities: vec![EntityState {
                id: 1,
                label: "You".into(),
                transform: Transform {
                    position: WorldCoord::surface(4.5, 2.0),
                    yaw: 0.0,
                    velocity: flatland_protocol::Velocity2D { vx: 0.0, vy: 0.0 },
                },
                vitals: None,
                attributes: None,
                skills: None,
                inside_building: Some("broker_hut".into()),
                tile_id: None,
                presentation_state: None,
                sprite_mode: None,
                progression_xp: None,
            }],
            player: None,
            resource_nodes: vec![],
            ground_drops: vec![],
            placed_containers: vec![],
            buildings: vec![BuildingView {
                id: "broker_hut".into(),
                label: "Broker".into(),
                x: 158.0,
                y: 124.0,
                width_m: 8.0,
                depth_m: 6.0,
                interior_blueprint: Some("broker_hut".into()),
                tags: vec![],
            }],
            doors: vec![flatland_protocol::DoorView {
                id: "broker_hut_exit".into(),
                building_id: "broker_hut".into(),
                x: 4.3,
                y: 0.9,
                open: true,
                portal: Some("front".into()),
            }],
            interior_map: None,
            npcs: vec![flatland_protocol::NpcView {
                id: "ada_broker".into(),
                label: "Ada".into(),
                x: 4.5,
                y: 2.0,
                building_id: Some("broker_hut".into()),
                role: "broker".into(),
                entity_id: None,
                life_state: None,
                hp_pct: None,
                can_trade: true,
                tile_id: None,
                behavior_state: None,
                presentation_state: None,
                sprite_mode: None,
            }],
            blueprints: vec![],
            world_width_m: 256.0,
            world_height_m: 256.0,
            terrain_zones: Vec::new(),
            z_platforms: Vec::new(),
            z_transitions: Vec::new(),
            world_clock: flatland_protocol::WorldClock::default(),
            inventory: std::collections::HashMap::new(),
            inventory_hints: std::collections::HashMap::new(),
            logs: VecDeque::new(),
            intents_sent: 0,
            ticks_received: 0,
            connected: true,
            disconnect_reason: None,
            show_stats: false,
            show_craft_menu: false,
            craft_menu_index: 0,
            craft_batch_quantity: 1,
            show_shop_menu: false,
            shop_catalog: None,
            shop_tab: ShopTab::default(),
            shop_menu_index: 0,
            shop_quantity: 1,
            shop_trade_log: VecDeque::new(),
            show_npc_verb_menu: false,
            npc_verb_target: None,
            npc_verb_index: 0,
            show_npc_chat: false,
            npc_chat: None,
            show_inventory_menu: false,
            inventory_menu_index: 0,
            show_move_picker: false,
            show_rename_prompt: false,
            rename_buffer: String::new(),
            move_picker_index: 0,
            move_picker: None,
            show_destroy_picker: false,
            destroy_confirm_pending: false,
            destroy_picker: None,
            combat_target: None,
            combat_target_label: None,
            in_combat: false,
            auto_attack: true,
            combat_has_los: false,
            attack_cd_ticks: 0,
            gcd_ticks: 0,
            weapon_ability_id: "unarmed".into(),
            mainhand_template_id: None,
            mainhand_label: None,
            worn: BTreeMap::new(),
            carry_mass: 0.0,
            carry_mass_max: 0.0,
            encumbrance: flatland_protocol::EncumbranceState::Light,
            inventory_stacks: Vec::new(),
            keychain_stacks: Vec::new(),
            combat_target_detail: None,
            cast_progress: None,
            ability_cooldowns: Vec::new(),
            blocking_active: false,
            max_target_slots: 1,
            combat_slots: Vec::new(),
            rotation_presets: Vec::new(),
            show_loadout_menu: false,
            show_keychain_menu: false,
            keychain_menu_index: 0,
            show_rotation_editor: false,
            loadout_menu_index: 0,
            rotation_editor: RotationEditorState::default(),
            harvest_in_progress: false,
            harvest_started_at: None,
            pending_craft_ack: None,
            quest_log: Vec::new(),
            interactables: Vec::new(),
            show_quest_offer: false,
            pending_quest_offer: None,
            show_quest_menu: false,
            quest_menu_index: 0,
            quest_withdraw_confirm: false,
            progression_curve: None,
        };
        state.player = state.entities.first().cloned();
        assert_eq!(
            state.nearest_interact_target().as_deref(),
            Some("ada_broker")
        );
    }

    #[test]
    fn nearby_containers_hides_chest_out_of_range_and_locked_without_key() {
        let mut state = sample_state();
        // Player is at (128, 128) per sample_state(). One chest just inside
        // CONTAINER_RANGE_M, one clearly beyond it.
        state.placed_containers = vec![
            flatland_protocol::PlacedContainerView {
                id: "near".into(),
                template_id: "wooden_chest_small".into(),
                display_name: "Wooden Chest".into(),
                x: 130.0,
                y: 128.0,
                z: 0.0,
                locked: true,
                accessible: true,
                owner_character_id: None,
                contents: vec![flatland_protocol::ItemStack::simple("iron_ore", 2)],
                lock_id: None,
                capacity_volume: None,
                item_instance_id: Some(uuid::Uuid::from_u128(1)),
                tile_id: None,
            },
            flatland_protocol::PlacedContainerView {
                id: "far".into(),
                template_id: "wooden_chest_small".into(),
                display_name: "Distant Chest".into(),
                x: 128.0 + CONTAINER_RANGE_M + 5.0,
                y: 128.0,
                z: 0.0,
                locked: false,
                accessible: true,
                owner_character_id: None,
                contents: vec![flatland_protocol::ItemStack::simple("lumber", 1)],
                lock_id: None,
                capacity_volume: None,
                item_instance_id: Some(uuid::Uuid::from_u128(2)),
                tile_id: None,
            },
        ];

        let nearby = state.nearby_containers();
        assert_eq!(
            nearby.len(),
            1,
            "far chest must not appear once out of range"
        );
        assert_eq!(nearby[0].view.id, "near");
        assert_eq!(nearby[0].rows.len(), 2, "shell row + contents");
        assert!(nearby[0].rows[0].is_chest_shell);

        // The same chest, but locked and inaccessible (no key held), must hide
        // contents but still show the selectable chest shell row.
        state.placed_containers[0].accessible = false;
        let nearby = state.nearby_containers();
        assert_eq!(nearby.len(), 1);
        assert_eq!(nearby[0].rows.len(), 1);
        assert!(nearby[0].rows[0].is_chest_shell);
    }

    #[test]
    fn placed_container_public_label_hides_owner_custom_name() {
        let owner = uuid::Uuid::from_u128(99);
        let mut state = sample_state();
        state.character_id = Some(uuid::Uuid::from_u128(1));
        state.inventory_hints.insert(
            "wooden_chest_medium".into(),
            InventoryHint {
                display_name: "Medium Wooden Chest".into(),
                category: "container".into(),
                base_mass: None,
                base_volume: None,
                capacity_volume: None,
                stackable: false,
            },
        );
        let chest = flatland_protocol::PlacedContainerView {
            id: "c1".into(),
            template_id: "wooden_chest_medium".into(),
            display_name: "Barry's Loot #a3f2".into(),
            x: 128.0,
            y: 128.0,
            z: 0.0,
            locked: false,
            accessible: true,
            owner_character_id: Some(owner),
            contents: vec![],
            lock_id: None,
            capacity_volume: None,
            item_instance_id: None,
            tile_id: None,
        };
        assert_eq!(
            state.placed_container_public_label(&chest),
            "Medium Wooden Chest"
        );
        state.character_id = Some(owner);
        assert_eq!(
            state.placed_container_public_label(&chest),
            "Barry's Loot #a3f2"
        );
    }

    #[test]
    fn location_context_lists_nearby_resource_node() {
        let mut state = sample_state();
        state.player = state.entities.first().cloned();
        state.resource_nodes[0].x = 128.2;
        state.resource_nodes[0].y = 128.0;
        let lines = state.location_context_lines();
        assert!(
            lines
                .iter()
                .any(|l| l.text.contains("Oak") && l.text.contains("harvest")),
            "expected resource node in context: {:?}",
            lines
        );
    }

    #[test]
    fn quest_board_usable_within_board_radius() {
        let mut state = sample_state();
        state.player = state.entities.first().cloned();
        state.interactables = vec![flatland_protocol::InteractableView {
            id: "board-1".into(),
            kind: "quest_board".into(),
            label: "Town Quest Board".into(),
            x: 130.5,
            y: 128.0,
            z: 0.0,
            board_id: Some("starter_town_board".into()),
        }];
        // ~2.5m away — outside the old 1.5m interact radius, inside the 3.0m board radius.
        assert_eq!(
            state.nearest_interact_target().as_deref(),
            Some("board-1"),
            "quest board should be selectable at ~2.5m"
        );
        let lines = state.location_context_lines();
        assert!(
            lines
                .iter()
                .any(|l| l.text.contains("Town Quest Board") && l.text.contains("f view quests")),
            "HUD should advertise f when board is in range: {:?}",
            lines
        );
    }

    #[test]
    fn inventory_selectable_rows_orders_worn_before_person_before_nearby() {
        let mut state = sample_state();
        state.worn.insert(
            BodySlot::Back,
            flatland_protocol::ItemStack {
                template_id: "travel_backpack".into(),
                quantity: 1,
                item_instance_id: Some(uuid::Uuid::from_u128(3)),
                props: Default::default(),
                contents: vec![flatland_protocol::ItemStack::simple("iron_ore", 1)],
                display_name: None,
                category: None,
                base_mass: None,
                base_volume: None,
                capacity_volume: None,
                stackable: None,
            },
        );
        state.inventory_stacks = vec![flatland_protocol::ItemStack::simple("lumber", 4)];
        state.placed_containers = vec![flatland_protocol::PlacedContainerView {
            id: "chest-1".into(),
            template_id: "wooden_chest_small".into(),
            display_name: "Wooden Chest".into(),
            x: 129.0,
            y: 128.0,
            z: 0.0,
            locked: false,
            accessible: true,
            owner_character_id: None,
            contents: vec![flatland_protocol::ItemStack::simple("wood_axe", 1)],
            lock_id: None,
            capacity_volume: None,
            item_instance_id: Some(uuid::Uuid::from_u128(4)),
            tile_id: None,
        }];

        let rows = state.inventory_selectable_rows();
        let sections: Vec<InventorySection> = rows.iter().map(|r| r.section).collect();
        assert_eq!(
            sections,
            vec![
                InventorySection::Worn,   // backpack shell
                InventorySection::Worn,   // iron_ore nested in backpack
                InventorySection::Person, // lumber
                InventorySection::Nearby, // chest shell
                InventorySection::Nearby, // wood_axe in chest
            ]
        );
        assert_eq!(rows[0].stack.template_id, "travel_backpack");
        assert!(rows[0].is_equip_shell);
        assert_eq!(rows[1].stack.template_id, "iron_ore");
        assert_eq!(rows[1].depth, 1);
        assert_eq!(rows[2].stack.template_id, "lumber");
        assert!(rows[3].is_chest_shell);
        assert_eq!(rows[4].stack.template_id, "wood_axe");
        assert_eq!(rows[4].depth, 1);

        let lines = state.inventory_browser_lines();
        assert!(lines.iter().any(|l| matches!(
            l,
            InventoryBrowserLine::Section(s) if s.contains("Worn")
        )));
        assert!(lines.iter().any(|l| matches!(
            l,
            InventoryBrowserLine::Item { text, .. } if text.contains("travel_backpack")
                || text.contains("backpack")
        )));
    }

    #[test]
    fn move_destinations_for_excludes_current_location_and_always_offers_drop_and_cancel() {
        let mut state = sample_state();
        let back_id = uuid::Uuid::from_u128(5);
        state.worn.insert(
            BodySlot::Back,
            flatland_protocol::ItemStack {
                template_id: "travel_backpack".into(),
                quantity: 1,
                item_instance_id: Some(back_id),
                props: Default::default(),
                contents: Vec::new(),
                display_name: None,
                category: Some("container".into()),
                base_mass: None,
                base_volume: None,
                capacity_volume: Some(80.0),
                stackable: None,
            },
        );
        state.placed_containers = vec![flatland_protocol::PlacedContainerView {
            id: "chest-1".into(),
            template_id: "wooden_chest_small".into(),
            display_name: "Wooden Chest".into(),
            x: 129.0,
            y: 128.0,
            z: 0.0,
            locked: false,
            accessible: true,
            owner_character_id: None,
            contents: Vec::new(),
            lock_id: None,
            capacity_volume: None,
            item_instance_id: Some(uuid::Uuid::from_u128(6)),
            tile_id: None,
        }];

        // Item currently sitting loose on the person (Root): backpack + nearby
        // chest should both be offered, plus Drop/Cancel, but not "Root" itself.
        let opts = state.move_destinations_for(
            &flatland_protocol::InventoryLocation::Root,
            None,
            None,
            "lumber",
        );
        assert!(!opts.iter().any(|o| matches!(
            &o.kind,
            MoveOptionKind::Move { location, .. } if *location == flatland_protocol::InventoryLocation::Root
        )));
        assert!(opts.iter().any(|o| matches!(
            &o.kind,
            MoveOptionKind::Move { location, parent_instance_id, .. }
                if *location == flatland_protocol::InventoryLocation::Worn {
                    slot: BodySlot::Back,
                } && *parent_instance_id == Some(back_id)
        )));
        assert!(opts.iter().any(|o| matches!(
            &o.kind,
            MoveOptionKind::Move { location, .. }
                if *location == flatland_protocol::InventoryLocation::Placed { container_id: "chest-1".into() }
        )));
        assert!(matches!(opts.last().unwrap().kind, MoveOptionKind::Cancel));
        assert!(matches!(opts[opts.len() - 2].kind, MoveOptionKind::Drop));

        // Item currently inside the worn backpack: the backpack itself must be
        // excluded from its own destination list (can't move an item into the
        // container it's already in).
        let from_backpack = flatland_protocol::InventoryLocation::Worn {
            slot: BodySlot::Back,
        };
        let opts = state.move_destinations_for(&from_backpack, Some(back_id), None, "iron_ore");
        assert!(!opts.iter().any(|o| matches!(
            &o.kind,
            MoveOptionKind::Move { location, parent_instance_id, .. }
                if *location == from_backpack && *parent_instance_id == Some(back_id)
        )));
        assert!(opts.iter().any(|o| matches!(
            &o.kind,
            MoveOptionKind::Move { location, .. } if *location == flatland_protocol::InventoryLocation::Root
        )));
    }

    #[test]
    fn worn_rows_orders_all_body_slots_and_nests_belt_loop_contents() {
        let mut state = sample_state();
        // Insert out of display order — BTreeMap iteration must still yield the
        // canonical Head/Body/Arms/Legs/Feet/Back/Waist order regardless.
        state.worn.insert(
            BodySlot::Waist,
            flatland_protocol::ItemStack {
                template_id: "simple_belt".into(),
                quantity: 1,
                item_instance_id: Some(uuid::Uuid::from_u128(10)),
                props: Default::default(),
                contents: vec![flatland_protocol::ItemStack::simple("leather_pouch", 1)],
                display_name: None,
                category: Some("container".into()),
                base_mass: None,
                base_volume: None,
                capacity_volume: None,
                stackable: None,
            },
        );
        state.worn.insert(
            BodySlot::Head,
            flatland_protocol::ItemStack {
                template_id: "cloth_cap".into(),
                quantity: 1,
                item_instance_id: Some(uuid::Uuid::from_u128(11)),
                props: Default::default(),
                contents: Vec::new(),
                display_name: None,
                category: Some("armor".into()),
                base_mass: None,
                base_volume: None,
                capacity_volume: None,
                stackable: None,
            },
        );
        state.worn.insert(
            BodySlot::Back,
            flatland_protocol::ItemStack {
                template_id: "travel_backpack".into(),
                quantity: 1,
                item_instance_id: Some(uuid::Uuid::from_u128(12)),
                props: Default::default(),
                contents: Vec::new(),
                display_name: None,
                category: Some("container".into()),
                base_mass: None,
                base_volume: None,
                capacity_volume: None,
                stackable: None,
            },
        );

        let rows = state.worn_rows();
        // Head, then Back, then Waist (+ nested pouch) — enum declaration order.
        assert_eq!(rows.len(), 4);
        assert_eq!(rows[0].stack.template_id, "cloth_cap");
        assert!(rows[0].is_equip_shell);
        assert_eq!(rows[1].stack.template_id, "travel_backpack");
        assert!(rows[1].is_equip_shell);
        assert_eq!(rows[2].stack.template_id, "simple_belt");
        assert!(rows[2].is_equip_shell);
        assert_eq!(rows[3].stack.template_id, "leather_pouch");
        assert_eq!(rows[3].depth, 1);
        assert!(!rows[3].is_equip_shell);
    }

    #[test]
    fn move_destinations_for_offers_belt_loop_but_hides_armor_slots() {
        let mut state = sample_state();
        state.worn.insert(
            BodySlot::Waist,
            flatland_protocol::ItemStack {
                template_id: "simple_belt".into(),
                quantity: 1,
                item_instance_id: Some(uuid::Uuid::from_u128(20)),
                props: Default::default(),
                contents: Vec::new(),
                display_name: Some("Simple Belt".into()),
                category: Some("container".into()),
                base_mass: None,
                base_volume: None,
                capacity_volume: None,
                stackable: None,
            },
        );
        state.worn.insert(
            BodySlot::Head,
            flatland_protocol::ItemStack {
                template_id: "cloth_cap".into(),
                quantity: 1,
                item_instance_id: Some(uuid::Uuid::from_u128(21)),
                props: Default::default(),
                contents: Vec::new(),
                display_name: Some("Cloth Cap".into()),
                category: Some("armor".into()),
                base_mass: None,
                base_volume: None,
                capacity_volume: None,
                stackable: None,
            },
        );

        let opts = state.move_destinations_for(
            &flatland_protocol::InventoryLocation::Root,
            None,
            None,
            "leather_pouch",
        );
        assert!(
            opts.iter().any(|o| matches!(
                &o.kind,
                MoveOptionKind::Move { location, .. }
                    if *location == flatland_protocol::InventoryLocation::Worn { slot: BodySlot::Waist }
            )),
            "belt loop must be offered when moving a pouch"
        );
        assert!(
            !opts.iter().any(|o| matches!(
                &o.kind,
                MoveOptionKind::Move { location, .. }
                    if *location == flatland_protocol::InventoryLocation::Worn { slot: BodySlot::Head }
            )),
            "armor slots can't hold other items and must not appear as move destinations"
        );
        let belt_opt = opts
            .iter()
            .find(|o| matches!(
                &o.kind,
                MoveOptionKind::Move { location, .. }
                    if *location == flatland_protocol::InventoryLocation::Worn { slot: BodySlot::Waist }
            ))
            .unwrap();
        assert!(belt_opt.label.contains("belt loop"));

        let opts = state.move_destinations_for(
            &flatland_protocol::InventoryLocation::Root,
            None,
            None,
            "lumber",
        );
        assert!(
            !opts.iter().any(|o| o.label.contains("belt loop")),
            "loose materials must not target the belt shell — only nested pouches"
        );
    }

    #[test]
    fn move_destinations_for_offers_dimensional_pouch_on_belt() {
        let mut state = sample_state();
        let belt_id = uuid::Uuid::from_u128(30);
        let pouch_id = uuid::Uuid::from_u128(31);
        state.worn.insert(
            BodySlot::Waist,
            flatland_protocol::ItemStack {
                template_id: "simple_belt".into(),
                quantity: 1,
                item_instance_id: Some(belt_id),
                props: Default::default(),
                contents: vec![flatland_protocol::ItemStack {
                    template_id: "dimensional_pouch".into(),
                    quantity: 1,
                    item_instance_id: Some(pouch_id),
                    props: Default::default(),
                    contents: Vec::new(),
                    display_name: Some("Dimensional Pouch".into()),
                    category: Some("container".into()),
                    base_mass: None,
                    base_volume: None,
                    capacity_volume: Some(200.0),
                    stackable: None,
                }],
                display_name: Some("Simple Belt".into()),
                category: Some("container".into()),
                base_mass: None,
                base_volume: None,
                capacity_volume: None,
                stackable: None,
            },
        );

        let opts = state.move_destinations_for(
            &flatland_protocol::InventoryLocation::Root,
            None,
            None,
            "iron_ore",
        );
        assert!(
            opts.iter().any(|o| matches!(
                &o.kind,
                MoveOptionKind::Move {
                    location,
                    parent_instance_id,
                    ..
                } if *location == flatland_protocol::InventoryLocation::Worn { slot: BodySlot::Waist }
                    && *parent_instance_id == Some(pouch_id)
            )),
            "dimensional pouch clipped on belt must accept loose items"
        );
        assert!(
            opts.iter().any(|o| o.label.contains("Dimensional Pouch")),
            "destination label should name the pouch"
        );
    }

    #[test]
    fn container_volume_label_on_placed_chest_shell() {
        let mut state = sample_state();
        state.placed_containers = vec![flatland_protocol::PlacedContainerView {
            id: "chest-1".into(),
            template_id: "wooden_chest_small".into(),
            display_name: "Camp Chest".into(),
            x: 129.0,
            y: 128.0,
            z: 0.0,
            locked: false,
            accessible: true,
            owner_character_id: None,
            contents: vec![flatland_protocol::ItemStack {
                template_id: "iron_ore".into(),
                quantity: 2,
                item_instance_id: None,
                props: Default::default(),
                contents: Vec::new(),
                display_name: None,
                category: None,
                base_mass: None,
                base_volume: Some(2.0),
                capacity_volume: None,
                stackable: None,
            }],
            lock_id: None,
            capacity_volume: Some(60.0),
            item_instance_id: Some(uuid::Uuid::from_u128(4)),
            tile_id: None,
        }];
        let nearby = state.nearby_containers();
        let label = state.container_volume_label(&nearby[0].rows[0]);
        assert!(
            label.contains("vol 4/60"),
            "expected used/cap in label, got {label}"
        );
        assert!(
            label.contains("56 free"),
            "expected free space, got {label}"
        );
    }

    #[test]
    fn key_pair_chest_label_from_placed_lock_id() {
        let mut state = sample_state();
        let owner = uuid::Uuid::from_u128(77);
        state.character_id = Some(owner);
        let lock = uuid::Uuid::from_u128(99).to_string();
        state.placed_containers = vec![flatland_protocol::PlacedContainerView {
            id: "chest-1".into(),
            template_id: "wooden_chest_small".into(),
            display_name: "Barry's Loot #a3f2".into(),
            x: 129.0,
            y: 128.0,
            z: 0.0,
            locked: true,
            accessible: true,
            owner_character_id: Some(owner),
            contents: Vec::new(),
            lock_id: Some(lock.clone()),
            capacity_volume: None,
            item_instance_id: Some(uuid::Uuid::from_u128(4)),
            tile_id: None,
        }];
        let key_id = uuid::Uuid::from_u128(5);
        let key = flatland_protocol::ItemStack {
            template_id: KEY_TEMPLATE.into(),
            quantity: 1,
            item_instance_id: Some(key_id),
            props: BTreeMap::from([
                (PROP_OPENS_LOCK_ID.into(), lock),
                (
                    PROP_OPENS_CONTAINER_NAME.into(),
                    "Barry's Loot #a3f2".into(),
                ),
            ]),
            contents: Vec::new(),
            display_name: Some("Container Key".into()),
            category: Some("key".into()),
            base_mass: None,
            base_volume: None,
            capacity_volume: None,
            stackable: None,
        };
        state.inventory_stacks = vec![key.clone()];
        assert_eq!(
            state.key_pair_chest_label(&key).as_deref(),
            Some("Barry's Loot #a3f2")
        );
        assert!(state.key_drop_blocked(&key));
    }

    #[test]
    fn key_pair_chest_label_prefers_cached_name_when_chest_out_of_range() {
        let mut state = sample_state();
        let lock = uuid::Uuid::from_u128(101).to_string();
        let key = flatland_protocol::ItemStack {
            template_id: KEY_TEMPLATE.into(),
            quantity: 1,
            item_instance_id: Some(uuid::Uuid::from_u128(7)),
            props: BTreeMap::from([
                (PROP_OPENS_LOCK_ID.into(), lock),
                (PROP_OPENS_CONTAINER_NAME.into(), "Camp Stash".into()),
            ]),
            contents: Vec::new(),
            display_name: None,
            category: Some("key".into()),
            base_mass: None,
            base_volume: None,
            capacity_volume: None,
            stackable: None,
        };
        state.placed_containers.clear();
        assert_eq!(
            state.key_pair_chest_label(&key).as_deref(),
            Some("Camp Stash")
        );
    }

    #[test]
    fn key_drop_allowed_when_paired_chest_unlocked() {
        let mut state = sample_state();
        let lock = uuid::Uuid::from_u128(100).to_string();
        let key_id = uuid::Uuid::from_u128(6);
        state.placed_containers = vec![flatland_protocol::PlacedContainerView {
            id: "chest-1".into(),
            template_id: "wooden_chest_small".into(),
            display_name: "Camp Chest".into(),
            x: 129.0,
            y: 128.0,
            z: 0.0,
            locked: false,
            accessible: true,
            owner_character_id: None,
            contents: Vec::new(),
            lock_id: Some(lock.clone()),
            capacity_volume: None,
            item_instance_id: None,
            tile_id: None,
        }];
        let key = flatland_protocol::ItemStack {
            template_id: KEY_TEMPLATE.into(),
            quantity: 1,
            item_instance_id: Some(key_id),
            props: BTreeMap::from([(PROP_OPENS_LOCK_ID.into(), lock)]),
            contents: Vec::new(),
            display_name: None,
            category: Some("key".into()),
            base_mass: None,
            base_volume: None,
            capacity_volume: None,
            stackable: None,
        };
        state.inventory_stacks = vec![key.clone()];
        assert!(!state.key_drop_blocked(&key));
        let opts = state.move_destinations_for(
            &flatland_protocol::InventoryLocation::Root,
            None,
            Some(key_id),
            KEY_TEMPLATE,
        );
        assert!(opts.iter().any(|o| o.kind == MoveOptionKind::Drop));
    }

    #[test]
    fn combat_hud_refreshes_progression_xp_when_entity_stale() {
        use flatland_protocol::{CombatHud, ProgressionXp, ProgressionCurve};

        let mut state = sample_state();
        let curve = ProgressionCurve::default();
        let bootstrap = ProgressionXp::bootstrap_new(
            curve.baseline_display,
            curve.xp_base,
            curve.xp_growth,
        );
        let mut fresh = bootstrap.clone();
        fresh.strength += 0.08;
        if let Some(player) = state.player.as_mut() {
            player.progression_xp = Some(bootstrap);
        }

        let combat = CombatHud {
            progression_xp: Some(fresh.clone()),
            progression_baseline: curve.baseline_display,
            progression_xp_base: curve.xp_base,
            progression_xp_growth: curve.xp_growth,
            attributes: state.player.as_ref().and_then(|p| p.attributes),
            skills: state.player.as_ref().and_then(|p| p.skills.clone()),
            ..CombatHud::default()
        };
        state.apply_combat_hud(&combat);

        let xp = state
            .player
            .as_ref()
            .and_then(|p| p.progression_xp.as_ref())
            .expect("xp");
        assert!((xp.strength - fresh.strength).abs() < 0.001);
        assert!(state.progression_curve.is_some());
    }
}