flatland_client_ui/

world.rs

use crate::color::RgbColor;
use crate::interior_wall_layout::{interior_door_display_xy, interior_wall_glyph_line};
use flatland_client_lib::GameState;
use flatland_protocol::{BuildingView, InteriorMapView, TerrainKindView};

use crate::map_presentation::{self, MapPresentation};

/// The TUI map uses one terminal cell per world meter on both axes so terrain, entities,
/// resources, and mouse targeting share the same grid. Terminal fonts are taller than wide,
/// so buildings look vertically stretched compared to the content-admin editor.

pub struct WorldView {
    pub width: usize,
    pub height: usize,
    pub cells: Vec<String>,
    /// Per-cell foreground color from presentation catalog (None = entity-specific style).
    pub cell_fg: Vec<Option<RgbColor>>,
    /// T1 target ring (red).
    pub target_t1_cells: Vec<bool>,
    /// T2 target ring (blue).
    pub target_t2_cells: Vec<bool>,
    pub origin_x: f32,
    pub origin_y: f32,
    pub inside_building: Option<String>,
}

/// Presentation flags for [`WorldView::build_with_options`].
#[derive(Debug, Clone, Copy)]
pub struct WorldViewOptions {
    /// Paint local player `@` at view center (TUI). Gfx uses a sprite instead.
    pub paint_local_player: bool,
    /// Paint NPCs, resources, loot, chests, quest boards, entities into the cell grid.
    /// Gfx sets this false and draws those at continuous world coordinates.
    pub paint_overlays: bool,
}

impl Default for WorldViewOptions {
    fn default() -> Self {
        Self {
            paint_local_player: true,
            paint_overlays: true,
        }
    }
}

impl WorldViewOptions {
    /// Terrain / walls only — gfx draws movers at precise x,y.
    pub fn terrain_only() -> Self {
        Self {
            paint_local_player: false,
            paint_overlays: false,
        }
    }
}

impl WorldView {
    pub fn build_with_target(
        state: &GameState,
        view_w: usize,
        view_h: usize,
        map_target: Option<(f32, f32)>,
    ) -> Self {
        Self::build_with_options(
            state,
            view_w,
            view_h,
            map_target,
            WorldViewOptions::default(),
        )
    }

    /// Like [`build_with_target`] with gfx/TUI presentation flags.
    pub fn build_with_options(
        state: &GameState,
        view_w: usize,
        view_h: usize,
        map_target: Option<(f32, f32)>,
        options: WorldViewOptions,
    ) -> Self {
        let (px, py) = state.player_position();
        Self::build_with_anchor(state, view_w, view_h, px, py, map_target, options)
    }

    /// Build a view anchored at explicit world coordinates (gfx uses smoothed camera).
    pub fn build_with_anchor(
        state: &GameState,
        view_w: usize,
        view_h: usize,
        anchor_x: f32,
        anchor_y: f32,
        map_target: Option<(f32, f32)>,
        options: WorldViewOptions,
    ) -> Self {
        map_presentation::maybe_reload_for_content_rev(state.content_rev);
        let px = anchor_x;
        let py = anchor_y;
        let inside_building = state.effective_inside_building();

        let width = view_w.max(3);
        let height = view_h.max(3);
        let grass = map_presentation::terrain_for(TerrainKindView::Grass);
        let mut cells = vec![grass.glyph.clone(); width * height];
        let mut cell_fg = vec![Some(grass.color); width * height];

        let half_w = (width / 2) as i32;
        let half_h = (height / 2) as i32;

        // Interior rendering is authoritative from `inside_building`, not stale `interior_map`.
        if let (Some(_bid), Some(interior)) =
            (inside_building.as_deref(), state.interior_map.as_ref())
        {
            let player_z = state
                .player
                .as_ref()
                .map(|p| p.transform.position.z)
                .unwrap_or(0.0);
            let active_floor = if interior.floor_height_m > f32::EPSILON {
                (player_z / interior.floor_height_m).round() as i32
            } else {
                0
            };
            paint_interior_background(&mut cells, &mut cell_fg, width, height, interior);
            paint_interior_rooms(
                &mut cells,
                &mut cell_fg,
                width,
                height,
                interior,
                px,
                py,
                half_w,
                half_h,
                active_floor,
            );
            let door_gaps = interior_door_gaps_snapped(interior, &state.doors, active_floor);
            paint_interior_merged_walls(
                &mut cells,
                &mut cell_fg,
                width,
                height,
                &interior.rooms,
                active_floor,
                px,
                py,
                half_w,
                half_h,
                &door_gaps,
            );
        } else {
            paint_terrain(
                &mut cells,
                &mut cell_fg,
                width,
                height,
                state,
                px,
                py,
                half_w,
                half_h,
            );

            for building in &state.buildings {
                if building.tags.iter().any(|t| t == "well") {
                    paint_well(
                        &mut cells,
                        &mut cell_fg,
                        width,
                        height,
                        building,
                        px,
                        py,
                        half_w,
                        half_h,
                    );
                } else {
                    paint_building_walls_centered(
                        &mut cells,
                        &mut cell_fg,
                        width,
                        height,
                        building,
                        px,
                        py,
                        half_w,
                        half_h,
                    );
                }
            }
        }

        if options.paint_overlays {
            for door in &state.doors {
                let (wx, wy) = match (inside_building.as_ref(), state.interior_map.as_ref()) {
                    (Some(_), Some(interior)) => {
                        let player_z = state
                            .player
                            .as_ref()
                            .map(|p| p.transform.position.z)
                            .unwrap_or(0.0);
                        let active_floor = if interior.floor_height_m > f32::EPSILON {
                            (player_z / interior.floor_height_m).round() as i32
                        } else {
                            0
                        };
                        interior_door_display_xy(interior, active_floor, &door.id, door.x, door.y)
                    }
                    _ => (door.x, door.y),
                };
                if let Some((gx, gy)) =
                    world_to_grid(wx, wy, px, py, half_w, half_h, width, height)
                {
                    let idx = gy * width + gx;
                    paint_presentation(
                        &mut cells,
                        &mut cell_fg,
                        idx,
                        &map_presentation::door_presentation(door.open),
                    );
                }
            }

            for npc in &state.npcs {
                if let Some((gx, gy)) =
                    world_to_grid(npc.x, npc.y, px, py, half_w, half_h, width, height)
                {
                    let idx = gy * width + gx;
                    paint_presentation(
                        &mut cells,
                        &mut cell_fg,
                        idx,
                        &map_presentation::npc_for(npc),
                    );
                }
            }

            let ground = empty_ground_glyph();
            let player_glyph = map_presentation::player_presentation().glyph;
            for node in &state.resource_nodes {
                if let Some((gx, gy)) =
                    world_to_grid(node.x, node.y, px, py, half_w, half_h, width, height)
                {
                    let idx = gy * width + gx;
                    let pres = map_presentation::resource_for(node);
                    if can_paint_world_object(&cells[idx], &ground, &player_glyph) {
                        paint_presentation(&mut cells, &mut cell_fg, idx, &pres);
                    }
                }
            }

            for drop in &state.ground_drops {
                if let Some((gx, gy)) =
                    world_to_grid(drop.x, drop.y, px, py, half_w, half_h, width, height)
                {
                    let idx = gy * width + gx;
                    if can_paint_world_object(&cells[idx], &ground, &player_glyph) {
                        paint_presentation(
                            &mut cells,
                            &mut cell_fg,
                            idx,
                            &map_presentation::loot_presentation(),
                        );
                    }
                }
            }

            for chest in &state.placed_containers {
                if let Some((gx, gy)) =
                    world_to_grid(chest.x, chest.y, px, py, half_w, half_h, width, height)
                {
                    let idx = gy * width + gx;
                    if can_paint_world_object(&cells[idx], &ground, &player_glyph) {
                        paint_presentation(
                            &mut cells,
                            &mut cell_fg,
                            idx,
                            &map_presentation::chest_presentation(chest.locked),
                        );
                    }
                }
            }

            if state.effective_inside_building().is_none() {
                for inter in &state.interactables {
                    if inter.kind != "quest_board" {
                        continue;
                    }
                    if let Some((gx, gy)) =
                        world_to_grid(inter.x, inter.y, px, py, half_w, half_h, width, height)
                    {
                        let idx = gy * width + gx;
                        if can_paint_world_object(&cells[idx], &ground, &player_glyph) {
                            paint_presentation(
                                &mut cells,
                                &mut cell_fg,
                                idx,
                                &map_presentation::quest_board_presentation(),
                            );
                        }
                    }
                }
            }

            for entity in &state.entities {
                // When gfx draws a sprite for the local player, omit the `@` glyph.
                if !options.paint_local_player && entity.id == state.entity_id {
                    continue;
                }
                if entity.id != state.entity_id
                    && entity.inside_building.as_deref() != inside_building.as_deref()
                {
                    continue;
                }
                if let (Some(_), Some(interior)) =
                    (inside_building.as_deref(), state.interior_map.as_ref())
                {
                    let player_z = state
                        .player
                        .as_ref()
                        .map(|p| p.transform.position.z)
                        .unwrap_or(0.0);
                    if interior.floor_height_m > f32::EPSILON {
                        let pf = (player_z / interior.floor_height_m).round() as i32;
                        let ef =
                            (entity.transform.position.z / interior.floor_height_m).round() as i32;
                        if pf != ef {
                            continue;
                        }
                    }
                }
                if let Some(pres) = entity_presentation(entity, state.entity_id) {
                    if let Some((gx, gy)) = world_to_grid(
                        entity.transform.position.x,
                        entity.transform.position.y,
                        px,
                        py,
                        half_w,
                        half_h,
                        width,
                        height,
                    ) {
                        let idx = gy * width + gx;
                        paint_presentation(&mut cells, &mut cell_fg, idx, &pres);
                    }
                }
            }
        }

        if options.paint_local_player {
            if state.player_entity().is_some() {
                let cx = half_w as usize;
                let cy = half_h as usize;
                let idx = cy * width + cx;
                if idx < cells.len() {
                    paint_presentation(
                        &mut cells,
                        &mut cell_fg,
                        idx,
                        &map_presentation::player_presentation(),
                    );
                }
            }
        }

        let mut target_t1_cells = vec![false; cells.len()];
        let mut target_t2_cells = vec![false; cells.len()];
        if options.paint_overlays {
            for (slot, cells_out) in [(1, &mut target_t1_cells), (2, &mut target_t2_cells)] {
                let target_id = state
                    .combat_slots
                    .iter()
                    .find(|s| s.slot_index == slot)
                    .and_then(|s| s.target_entity_id)
                    .or_else(|| if slot == 1 { state.combat_target } else { None });
                let Some(target_id) = target_id else {
                    continue;
                };
                let (tx, ty) = if let Some(npc) = state
                    .npcs
                    .iter()
                    .find(|n| n.entity_id == Some(target_id))
                {
                    (npc.x, npc.y)
                } else if let Some(entity) = state.entities.iter().find(|e| e.id == target_id) {
                    (
                        entity.transform.position.x,
                        entity.transform.position.y,
                    )
                } else {
                    continue;
                };
                if let Some((gx, gy)) =
                    world_to_grid(tx, ty, px, py, half_w, half_h, width, height)
                {
                    let idx = gy * width + gx;
                    if idx < cells_out.len() {
                        cells_out[idx] = true;
                    }
                }
            }
        }

        if options.paint_overlays {
            if let Some((tx, ty)) = map_target {
                if let Some((gx, gy)) = world_to_grid(tx, ty, px, py, half_w, half_h, width, height)
                {
                    let idx = gy * width + gx;
                    if idx < cells.len() {
                        cells[idx] = "X".into();
                        cell_fg[idx] = Some(RgbColor::YELLOW);
                    }
                }
            }
        }

        Self {
            width,
            height,
            cells,
            cell_fg,
            target_t1_cells,
            target_t2_cells,
            origin_x: px,
            origin_y: py,
            inside_building,
        }
    }
}

fn paint_presentation(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    idx: usize,
    pres: &MapPresentation,
) {
    cells[idx] = pres.glyph.clone();
    cell_fg[idx] = Some(pres.color);
}

fn empty_ground_glyph() -> String {
    map_presentation::terrain_for(TerrainKindView::Grass).glyph
}

fn entity_presentation(
    entity: &flatland_protocol::EntityState,
    player_id: u64,
) -> Option<MapPresentation> {
    if entity.id == player_id {
        return Some(map_presentation::player_presentation());
    }
    if entity
        .vitals
        .as_ref()
        .is_some_and(|v| v.life_state == flatland_protocol::LifeState::Dead)
    {
        return Some(map_presentation::corpse_presentation());
    }
    Some(map_presentation::entity_fallback(&entity.label))
}

fn paint_interior_background(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    _width: usize,
    _height: usize,
    interior: &InteriorMapView,
) {
    let bg = crate::color::parse_color(&interior.background_color).unwrap_or(RgbColor::BLACK);
    for idx in 0..cells.len() {
        cells[idx] = " ".into();
        cell_fg[idx] = Some(bg);
    }
}

fn paint_interior_rooms(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    width: usize,
    height: usize,
    interior: &InteriorMapView,
    px: f32,
    py: f32,
    half_w: i32,
    half_h: i32,
    active_floor: i32,
) {
    let default_color = interior
        .default_floor_color
        .as_deref()
        .and_then(crate::color::parse_color)
        .unwrap_or(RgbColor::rgb(0x2a, 0x2a, 0x2a));
    for room in &interior.rooms {
        if room.floor != active_floor {
            continue;
        }
        let floor_color = room
            .floor_color
            .as_deref()
            .and_then(crate::color::parse_color)
            .unwrap_or(default_color);
        let glyph = room.floor_glyph.as_deref().unwrap_or(".").to_string();
        let x0 = room.x0.floor() as i32;
        let y0 = room.y0.floor() as i32;
        let x1 = room.x1.ceil() as i32 - 1;
        let y1 = room.y1.ceil() as i32 - 1;
        for wy in y0..=y1 {
            for wx in x0..=x1 {
                if let Some((gx, gy)) =
                    world_to_grid(wx as f32, wy as f32, px, py, half_w, half_h, width, height)
                {
                    let idx = gy * width + gx;
                    cells[idx] = glyph.clone();
                    cell_fg[idx] = Some(floor_color);
                }
            }
        }
    }
}

fn interior_door_gaps(
    interior: &InteriorMapView,
    doors: &[flatland_protocol::DoorView],
    active_floor: i32,
) -> Vec<(f32, f32)> {
    let room_floor = |id: &str| -> Option<i32> {
        interior
            .rooms
            .iter()
            .find(|r| r.id == id)
            .map(|r| r.floor)
    };
    let mut gaps: Vec<(f32, f32)> = interior
        .room_doors
        .iter()
        .filter_map(|d| {
            let on_floor = room_floor(&d.room_a) == Some(active_floor)
                || room_floor(&d.room_b) == Some(active_floor);
            if !on_floor {
                return None;
            }
            doors
                .iter()
                .find(|door| door.id == d.id)
                .filter(|door| door.open || d.kind == "stairs")
                .map(|door| (door.x, door.y))
        })
        .collect();
    for door in doors {
        if door.portal.is_some() && door.open {
            gaps.push((door.x, door.y));
        }
    }
    gaps
}

fn interior_door_gaps_snapped(
    interior: &flatland_protocol::InteriorMapView,
    doors: &[flatland_protocol::DoorView],
    floor: i32,
) -> Vec<(f32, f32)> {
    let mut gaps = Vec::new();
    for (x, y) in interior_door_gaps(interior, doors, floor) {
        // Match gap carving to door sprite — find door id at this authored position.
        let door_id = doors
            .iter()
            .find(|d| (d.x - x).abs() < 0.05 && (d.y - y).abs() < 0.05)
            .map(|d| d.id.as_str())
            .unwrap_or("");
        gaps.push(interior_door_display_xy(
            interior,
            floor,
            door_id,
            x,
            y,
        ));
    }
    gaps
}

fn near_door_gap(wx: i32, wy: i32, door_gaps: &[(f32, f32)]) -> bool {
    door_gaps
        .iter()
        .any(|(dx, dy)| (wx as f32 - dx).abs() < 1.0 && (wy as f32 - dy).abs() < 1.0)
}

const INTERIOR_WALL_EDGE_TOL: f32 = 0.6;

/// World grid row/column for a merged wall line (half-meter room edges).
fn interior_wall_grid_line(fixed: f32) -> i32 {
    interior_wall_glyph_line(fixed)
}

fn quant_interior_wall_coord(v: f32) -> i64 {
    (v * 1000.0).round() as i64
}

fn merge_interior_wall_intervals(mut intervals: Vec<(f32, f32)>) -> Vec<(f32, f32)> {
    if intervals.is_empty() {
        return intervals;
    }
    intervals.sort_by(|a, b| a.0.partial_cmp(&b.0).unwrap_or(std::cmp::Ordering::Equal));
    let mut out = vec![intervals[0]];
    for &(a, b) in intervals.iter().skip(1) {
        let last_idx = out.len() - 1;
        if a <= out[last_idx].1 + INTERIOR_WALL_EDGE_TOL {
            out[last_idx].1 = out[last_idx].1.max(b);
        } else {
            out.push((a, b));
        }
    }
    out
}

/// Paint merged interior walls — shared room edges become a single wall strip (matches sim).
fn paint_interior_merged_walls(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    width: usize,
    height: usize,
    rooms: &[flatland_protocol::InteriorRoomView],
    floor: i32,
    px: f32,
    py: f32,
    half_w: i32,
    half_h: i32,
    door_gaps: &[(f32, f32)],
) {
    use std::collections::HashMap;

    let mut horiz: HashMap<i64, Vec<(f32, f32)>> = HashMap::new();
    let mut vert: HashMap<i64, Vec<(f32, f32)>> = HashMap::new();

    for room in rooms.iter().filter(|r| r.floor == floor) {
        let west = room.x0.min(room.x1);
        let east = room.x0.max(room.x1);
        let south = room.y0.min(room.y1);
        let north = room.y0.max(room.y1);
        if east - west >= 0.25 {
            horiz.entry(quant_interior_wall_coord(south))
                .or_default()
                .push((west, east));
            horiz.entry(quant_interior_wall_coord(north))
                .or_default()
                .push((west, east));
        }
        if north - south >= 0.25 {
            vert.entry(quant_interior_wall_coord(west))
                .or_default()
                .push((south, north));
            vert.entry(quant_interior_wall_coord(east))
                .or_default()
                .push((south, north));
        }
    }

    for (key, intervals) in horiz {
        let fixed = key as f32 / 1000.0;
        let merged = merge_interior_wall_intervals(intervals);
        let wy = interior_wall_grid_line(fixed);
        for (start, end) in merged {
            if end - start < 0.2 {
                continue;
            }
            let x0 = start.round() as i32;
            let x1 = end.round() as i32;
            for wx in x0..=x1 {
                if !near_door_gap(wx, wy, door_gaps) {
                    paint_wall_cell(
                        cells,
                        cell_fg,
                        width,
                        height,
                        wx,
                        wy,
                        px,
                        py,
                        half_w,
                        half_h,
                        "-",
                    );
                }
            }
        }
    }

    for (key, intervals) in vert {
        let fixed = key as f32 / 1000.0;
        let merged = merge_interior_wall_intervals(intervals);
        let wx = interior_wall_grid_line(fixed);
        for (start, end) in merged {
            if end - start < 0.2 {
                continue;
            }
            let y0 = start.round() as i32;
            let y1 = end.round() as i32;
            for wy in y0..=y1 {
                if !near_door_gap(wx, wy, door_gaps) {
                    paint_wall_cell(
                        cells,
                        cell_fg,
                        width,
                        height,
                        wx,
                        wy,
                        px,
                        py,
                        half_w,
                        half_h,
                        "|",
                    );
                }
            }
        }
    }
}

fn paint_terrain(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    width: usize,
    height: usize,
    state: &GameState,
    px: f32,
    py: f32,
    _half_w: i32,
    _half_h: i32,
) {
    for gy in 0..height {
        for gx in 0..width {
            let Some((wx, wy)) = grid_to_world(gx, gy, px, py, width, height) else {
                continue;
            };
            let zone = state.terrain_zone_at(wx, wy);
            let kind = zone.map(|z| z.kind).unwrap_or(TerrainKindView::Grass);
            let elev = zone.map(|z| z.elevation).unwrap_or(0.0);
            let style = map_presentation::terrain_for_zone(
                kind,
                elev,
                zone.and_then(|z| z.glyph.as_deref()),
                zone.and_then(|z| z.color.as_deref()),
            );
            let idx = gy * width + gx;
            paint_presentation(cells, cell_fg, idx, &style);
        }
    }
}

fn paint_well(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    width: usize,
    height: usize,
    building: &BuildingView,
    px: f32,
    py: f32,
    half_w: i32,
    half_h: i32,
) {
    let hw = building.width_m / 2.0;
    let hd = building.depth_m / 2.0;
    let x0 = (building.x - hw).floor() as i32;
    let y0 = (building.y - hd).floor() as i32;
    let x1 = (building.x + hw).ceil() as i32 - 1;
    let y1 = (building.y + hd).ceil() as i32 - 1;
    let water = map_presentation::shallow_water_presentation();
    let center = map_presentation::well_center_presentation();

    for wy in y0..=y1 {
        for wx in x0..=x1 {
            let pres = if wx == building.x.round() as i32 && wy == building.y.round() as i32 {
                center.clone()
            } else {
                water.clone()
            };
            if let Some((gx, gy)) =
                world_to_grid(wx as f32, wy as f32, px, py, half_w, half_h, width, height)
            {
                let idx = gy * width + gx;
                if !is_wall(&cells[idx]) {
                    paint_presentation(cells, cell_fg, idx, &pres);
                }
            }
        }
    }
}

fn paint_building_walls_centered(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    width: usize,
    height: usize,
    building: &BuildingView,
    px: f32,
    py: f32,
    half_w: i32,
    half_h: i32,
) {
    let hw = building.width_m / 2.0;
    let hd = building.depth_m / 2.0;
    paint_building_walls(
        cells,
        cell_fg,
        width,
        height,
        building.x - hw,
        building.y - hd,
        building.width_m,
        building.depth_m,
        px,
        py,
        half_w,
        half_h,
        &[],
    );
}

/// Paint perimeter walls for an axis-aligned rectangle (origin = south-west corner).
fn paint_building_walls(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    width: usize,
    height: usize,
    origin_x: f32,
    origin_y: f32,
    width_m: f32,
    depth_m: f32,
    px: f32,
    py: f32,
    half_w: i32,
    half_h: i32,
    door_gaps: &[(f32, f32)],
) {
    let x0 = origin_x.floor() as i32;
    let y0 = origin_y.floor() as i32;
    let x1 = (origin_x + width_m).ceil() as i32 - 1;
    let y1 = (origin_y + depth_m).ceil() as i32 - 1;

    if x1 < x0 || y1 < y0 {
        return;
    }

    for wx in x0..=x1 {
        if !near_door_gap(wx, y0, door_gaps) {
            paint_wall_cell(
                cells, cell_fg, width, height, wx, y0, px, py, half_w, half_h, "-",
            );
        }
        if !near_door_gap(wx, y1, door_gaps) {
            paint_wall_cell(
                cells, cell_fg, width, height, wx, y1, px, py, half_w, half_h, "-",
            );
        }
    }
    for wy in y0 + 1..y1 {
        if !near_door_gap(x0, wy, door_gaps) {
            paint_wall_cell(
                cells, cell_fg, width, height, x0, wy, px, py, half_w, half_h, "|",
            );
        }
        if !near_door_gap(x1, wy, door_gaps) {
            paint_wall_cell(
                cells, cell_fg, width, height, x1, wy, px, py, half_w, half_h, "|",
            );
        }
    }
    if !near_door_gap(x0, y0, door_gaps) {
        paint_wall_cell(
            cells, cell_fg, width, height, x0, y0, px, py, half_w, half_h, "+",
        );
    }
    if !near_door_gap(x1, y0, door_gaps) {
        paint_wall_cell(
            cells, cell_fg, width, height, x1, y0, px, py, half_w, half_h, "+",
        );
    }
    if !near_door_gap(x0, y1, door_gaps) {
        paint_wall_cell(
            cells, cell_fg, width, height, x0, y1, px, py, half_w, half_h, "+",
        );
    }
    if !near_door_gap(x1, y1, door_gaps) {
        paint_wall_cell(
            cells, cell_fg, width, height, x1, y1, px, py, half_w, half_h, "+",
        );
    }
}

fn paint_wall_cell(
    cells: &mut [String],
    cell_fg: &mut [Option<RgbColor>],
    width: usize,
    height: usize,
    wx: i32,
    wy: i32,
    px: f32,
    py: f32,
    half_w: i32,
    half_h: i32,
    ch: &str,
) {
    let Some((gx, gy)) = world_to_grid(wx as f32, wy as f32, px, py, half_w, half_h, width, height)
    else {
        return;
    };
    let idx = gy * width + gx;
    let ground = empty_ground_glyph();
    // Paint over terrain/floor, the interior background, and existing wall cells
    // (corner merge). Skipping the " " interior background is what made outer
    // perimeter walls (e.g. the south wall of a room at negative y) invisible.
    if cells[idx] == ground || cells[idx] == " " || is_wall(&cells[idx]) {
        cells[idx] = merge_wall_corner(&cells[idx], ch, &ground);
        cell_fg[idx] = Some(map_presentation::wall_presentation().color);
    }
}

fn is_wall(glyph: &str) -> bool {
    matches!(glyph.chars().next(), Some('+' | '-' | '|'))
}

/// Overlays (resources, loot, chests, boards) paint on any non-wall cell.
fn can_paint_world_object(glyph: &str, _ground: &str, _player_glyph: &str) -> bool {
    !is_wall(glyph)
}

fn merge_wall_corner(existing: &str, incoming: &str, ground: &str) -> String {
    // Interior background counts as paintable ground (outer perimeter walls sit on it).
    if existing == ground || existing == " " {
        return incoming.to_string();
    }
    if existing == incoming {
        return existing.to_string();
    }
    "+".to_string()
}

fn world_to_grid(
    x: f32,
    y: f32,
    px: f32,
    py: f32,
    half_w: i32,
    half_h: i32,
    width: usize,
    height: usize,
) -> Option<(usize, usize)> {
    let dx = (x - px).round() as i32;
    let dy = (y - py).round() as i32;

    if dx.abs() > half_w || dy.abs() > half_h {
        return None;
    }

    let gx = half_w + dx;
    let gy = half_h - dy;

    if gx < 0 || gy < 0 {
        return None;
    }
    let gx = gx as usize;
    let gy = gy as usize;
    if gx >= width || gy >= height {
        return None;
    }
    Some((gx, gy))
}

/// Inverse of [`world_to_grid`]: map view cell → world meters (cell center).
pub fn grid_to_world(
    gx: usize,
    gy: usize,
    px: f32,
    py: f32,
    view_w: usize,
    view_h: usize,
) -> Option<(f32, f32)> {
    if gx >= view_w || gy >= view_h {
        return None;
    }
    let half_w = (view_w / 2) as i32;
    let half_h = (view_h / 2) as i32;
    let dx = gx as i32 - half_w;
    let dy = half_h - gy as i32;
    Some((px + dx as f32, py + dy as f32))
}

#[cfg(test)]
mod tests {
    use super::*;
    use flatland_protocol::{
        BuildingView, EntityState, PlayerVitals, PrimaryAttributes, Transform, WorldCoord,
    };

    fn state_with_building(building: BuildingView) -> GameState {
        GameState {
            session_id: 1,
            entity_id: 1,
            character_id: None,
            tick: 0,
            chunk_rev: 0,
            content_rev: 0,
            publish_rev: 0,
            entities: vec![EntityState {
                id: 1,
                label: "You".into(),
                transform: Transform {
                    position: WorldCoord::surface(148.0, 118.0),
                    yaw: 0.0,
                    velocity: flatland_protocol::Velocity2D { vx: 0.0, vy: 0.0 },
                },
                vitals: Some(PlayerVitals::default()),
                attributes: Some(PrimaryAttributes::default()),
                skills: Some(flatland_protocol::PlayerSkills::default()),
                inside_building: None,
                tile_id: None,
                paperdoll_ref: None,
                presentation_state: None,
                sprite_mode: None,
                progression_xp: None,
                combat_cues: Vec::new(),
            }],
            player: None,
            resource_nodes: vec![],
            ground_drops: vec![],
            placed_containers: vec![],
            buildings: vec![building],
            doors: vec![],
            interior_map: None,
            npcs: vec![],
            blueprints: vec![],
            world_x0: 0.0,
            world_y0: 0.0,
            world_width_m: 256.0,
            world_height_m: 256.0,
            terrain_zones: vec![],
            z_platforms: vec![],
            z_transitions: vec![],
            z_bands_outdoor_backup: None,
            world_clock: flatland_protocol::WorldClock::default(),
            inventory: Default::default(),
            inventory_hints: Default::default(),
            logs: Default::default(),
            intents_sent: 0,
            ticks_received: 0,
            connected: true,
            disconnect_reason: None,
            show_stats: false,
            hud_log_hidden: false,
            show_equip_menu: false,
            equip_menu_index: 0,
            ledger: None,
            career: None,
            character_sheet_tab: flatland_client_lib::CharacterSheetTab::Character,
            ledger_period: flatland_client_lib::LedgerPeriod::Day,
            show_craft_menu: false,
            craft_menu_index: 0,
            craft_batch_quantity: 1,
            show_shop_menu: false,
            shop_catalog: None,
            bank_panel: None,
            bank_menu_index: 0,
            bank_ui_mode: flatland_client_lib::BankUiMode::Menu,
            storage_panel: None,
            market_panel: None,
            market_menu_index: 0,
            market_filter: String::new(),
            market_filter_focused: false,
            market_category_filter: None,
            market_buy_confirm: None,
            market_ui_mode: flatland_client_lib::MarketUiMode::Browse,
            storage_menu_index: 0,
            storage_ui_mode: flatland_client_lib::StorageUiMode::Menu,
            property_zones: vec![],
            tax_zones: vec![],
            growth_zones: vec![],
            biome_zones: vec![],
            property_plots: vec![],
            property_plot_settings: None,
            claim_mode: None,
            relocate_mode: None,
            sell_plot_confirm: None,
            sell_plot_armed_at: None,
            show_plant_menu: false,
            plant_menu_index: 0,
            show_farm_access: false,
            farm_access_name_draft: String::new(),
            farm_access_discount_bps: 0,
            farm_access_index: 0,
            plant_quantity: 1,
            shop_tab: flatland_client_lib::ShopTab::default(),
            shop_menu_index: 0,
            shop_quantity: 1,
            shop_trade_log: std::collections::VecDeque::new(),
            show_npc_verb_menu: false,
            npc_verb_target: None,
            npc_verb_index: 0,
            player_verbs: Default::default(),
            social_chat: Default::default(),
            trade_ui: Default::default(),
            whisper_pouch_ui: Default::default(),
            show_npc_chat: false,
            npc_chat: None,
            show_inventory_menu: false,
            inventory_menu_index: 0,
            inventory_tab: flatland_client_lib::InventoryTab::OnPerson,
            inventory_filter: String::new(),
            inventory_filter_focused: false,
            show_move_picker: false,
            show_rename_prompt: false,
            show_worker_rename: false,
            rename_buffer: String::new(),
            move_picker_index: 0,
            move_picker: None,
            show_grant_picker: false,
            grant_picker_index: 0,
            grant_picker: None,
            show_destroy_picker: false,
            destroy_confirm_pending: false,
            destroy_picker: None,
            combat_target: None,
            combat_target_label: None,
            ground_target: None,
            combat_fx: Vec::new(),
            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,
            offhand_template_id: None,
            offhand_label: None,
            mainhand_hand_slots: 1,
            defense: None,
            worn: std::collections::BTreeMap::new(),
            carry_mass: 0.0,
            carry_mass_max: 0.0,
            encumbrance: flatland_protocol::EncumbranceState::Light,
            inventory_stacks: Vec::new(),
            keychain_stacks: Vec::new(),
            whisper_pouch_stacks: Vec::new(),
            combat_target_detail: None,
            statuses: Vec::new(),
            cast_progress: None,
            timed_channel: None,
            ability_cooldowns: Vec::new(),
            blocking_active: false,
            max_target_slots: 1,
            combat_slots: Vec::new(),
            rotation_presets: Vec::new(),
            known_abilities: Vec::new(),
            ability_meta: std::collections::HashMap::new(),
            hotbar: vec![None; 9],
            max_abilities_per_rotation: 0,
            show_loadout_menu: false,
            show_keychain_menu: false,
            keychain_menu_index: 0,
            show_rotation_editor: false,
            loadout_menu_index: 0,
            loadout_hotbar_slot: 1,
            loadout_ability_index: 0,
            loadout_focus_presets: false,
            rotation_editor: Default::default(),
            harvest_in_progress: false,
            harvest_started_at: None,
            pending_craft_ack: None,
            pending_worker_job_ack: None,
            attending_worker_instance_id: 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,
            hired_workers: Vec::new(),
            show_workers_menu: false,
            workers_menu_index: 0,
            workers_menu_compact: false,
            worker_step_display: std::collections::BTreeMap::new(),
            worker_error_display: std::collections::BTreeMap::new(),
            show_worker_give_picker: false,
            worker_give_picker_index: 0,
            worker_give_picker: None,
            show_worker_give_target_picker: false,
            worker_give_target_picker_index: 0,
            worker_give_target_picker: None,
            show_worker_take_picker: false,
            worker_take_picker_index: 0,
            worker_take_picker: None,
            show_worker_teach_picker: false,
            worker_teach_picker_index: 0,
            worker_teach_picker: None,
            worker_route_editor: None,
            progression_curve: None,
        }
    }

    #[test]
    fn shallow_water_terrain_paints_tilde() {
        use flatland_protocol::TerrainZoneView;
        let mut state = state_with_building(BuildingView {
            id: "x".into(),
            label: "X".into(),
            x: 128.0,
            y: 128.0,
            width_m: 1.0,
            depth_m: 1.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        });
        state.terrain_zones.push(TerrainZoneView {
            id: "pond".into(),
            x0: 126.0,
            y0: 126.0,
            x1: 130.0,
            y1: 130.0,
            kind: TerrainKindView::ShallowWater,
            elevation: -0.5,
            glyph: None,
            color: None,
            tile_id: None,
            z_order: 0,
            channel_start_tick: None,
            channel_end_tick: None,
        });
        state.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: Some(PlayerVitals::default()),
            attributes: Some(PrimaryAttributes::default()),
            skills: Some(flatland_protocol::PlayerSkills::default()),
            inside_building: None,
            tile_id: None,
            paperdoll_ref: None,
            presentation_state: None,
            sprite_mode: None,
            progression_xp: None,
            combat_cues: Vec::new(),
        }];
        state.player = state.entities.first().cloned();
        let view = WorldView::build_with_target(&state, 9, 9, None);
        let flat = view.cells.join("");
        let water = map_presentation::shallow_water_presentation();
        assert!(
            flat.contains(&water.glyph),
            "expected water tiles ({:?}): {flat}",
            water.glyph
        );
        assert!(
            view.cell_fg.iter().any(|c| *c == Some(water.color)),
            "expected water color on terrain cells"
        );
    }

    #[test]
    fn zone_glyph_and_color_overrides_paint_on_map() {
        use flatland_protocol::TerrainZoneView;
        let mut state = state_with_building(BuildingView {
            id: "x".into(),
            label: "X".into(),
            x: 128.0,
            y: 128.0,
            width_m: 1.0,
            depth_m: 1.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        });
        state.terrain_zones.push(TerrainZoneView {
            id: "marked".into(),
            x0: 126.0,
            y0: 126.0,
            x1: 130.0,
            y1: 130.0,
            kind: TerrainKindView::Grass,
            elevation: 0.0,
            glyph: Some("%".into()),
            color: Some("magenta".into()),
            tile_id: None,
            z_order: 0,
            channel_start_tick: None,
            channel_end_tick: None,
        });
        state.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: Some(PlayerVitals::default()),
            attributes: Some(PrimaryAttributes::default()),
            skills: Some(flatland_protocol::PlayerSkills::default()),
            inside_building: None,
            tile_id: None,
            paperdoll_ref: None,
            presentation_state: None,
            sprite_mode: None,
            progression_xp: None,
            combat_cues: Vec::new(),
        }];
        state.player = state.entities.first().cloned();
        let view = WorldView::build_with_target(&state, 9, 9, None);
        let flat = view.cells.join("");
        assert!(
            flat.contains('%'),
            "expected custom zone glyph on map: {flat}"
        );
        assert!(
            view.cell_fg.iter().any(|c| *c == Some(RgbColor::MAGENTA)),
            "expected custom zone color on terrain cells"
        );
    }

    #[test]
    fn well_paints_water_ring_and_center() {
        let building = BuildingView {
            id: "town_well".into(),
            label: "Well".into(),
            x: 122.0,
            y: 106.0,
            width_m: 3.0,
            depth_m: 3.0,
            interior_blueprint: None,
            tags: vec!["well".into()],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let mut state = state_with_building(building);
        state.entities = vec![EntityState {
            id: 1,
            label: "You".into(),
            transform: Transform {
                position: WorldCoord::surface(120.0, 106.0),
                yaw: 0.0,
                velocity: flatland_protocol::Velocity2D { vx: 0.0, vy: 0.0 },
            },
            vitals: Some(PlayerVitals::default()),
            attributes: Some(PrimaryAttributes::default()),
            skills: Some(flatland_protocol::PlayerSkills::default()),
            inside_building: None,
            tile_id: None,
            paperdoll_ref: None,
            presentation_state: None,
            sprite_mode: None,
            progression_xp: None,
            combat_cues: Vec::new(),
        }];
        state.player = state.entities.first().cloned();
        let view = WorldView::build_with_target(&state, 9, 9, None);
        let flat = view.cells.join("");
        assert!(flat.contains('~'), "expected well water: {flat}");
        assert!(flat.contains('O'), "expected well center: {flat}");
    }

    #[test]
    fn broker_hut_draws_wall_outline() {
        let building = BuildingView {
            id: "broker_hut".into(),
            label: "Broker's Hut".into(),
            x: 148.0,
            y: 118.0,
            width_m: 8.0,
            depth_m: 6.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let mut state = state_with_building(building);
        state.player = state.entities.first().cloned();
        let view = WorldView::build_with_target(&state, 25, 15, None);
        let flat = view.cells.join("");
        assert!(flat.contains('+'), "expected corners: {flat}");
        assert!(flat.contains('-'), "expected horiz walls: {flat}");
        assert!(flat.contains('|'), "expected vert walls: {flat}");
    }

    #[test]
    fn interior_map_renders_rooms_and_walls() {
        use flatland_protocol::{InteriorMapView, InteriorRoomView};
        let building = BuildingView {
            id: "broker_hut".into(),
            label: "Broker's Hut".into(),
            x: 148.0,
            y: 118.0,
            width_m: 8.0,
            depth_m: 6.0,
            interior_blueprint: Some("broker_hut".into()),
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let mut state = state_with_building(building);
        state.interior_map = Some(InteriorMapView {
            building_id: "broker_hut".into(),
            blueprint_id: "broker_hut".into(),
            background_color: "#000000".into(),
            default_floor_color: Some("#2a2a2a".into()),
            floor_height_m: 3.0,
            z_platforms: vec![],
            z_transitions: vec![],
            rooms: vec![InteriorRoomView {
                id: "main".into(),
                label: "Main".into(),
                floor: 0,
                x0: 0.0,
                y0: 0.0,
                x1: 8.5,
                y1: 7.0,
                floor_color: None,
                floor_glyph: None,
            }],
            room_doors: vec![],
        });
        state.entities = vec![EntityState {
            id: 1,
            label: "You".into(),
            transform: Transform {
                position: WorldCoord::surface(4.0, 3.0),
                yaw: 0.0,
                velocity: flatland_protocol::Velocity2D { vx: 0.0, vy: 0.0 },
            },
            vitals: Some(PlayerVitals::default()),
            attributes: Some(PrimaryAttributes::default()),
            skills: Some(flatland_protocol::PlayerSkills::default()),
            inside_building: Some("broker_hut".into()),
            tile_id: None,
            paperdoll_ref: None,
            presentation_state: None,
            sprite_mode: None,
            progression_xp: None,
            combat_cues: Vec::new(),
        }];
        state.player = state.entities.first().cloned();
        let view = WorldView::build_with_target(&state, 25, 15, None);
        assert_eq!(view.inside_building.as_deref(), Some("broker_hut"));
        let flat = view.cells.join("");
        assert!(flat.contains('+'), "expected interior walls: {flat}");
        assert!(flat.contains('@'), "expected player marker: {flat}");
    }

    #[test]
    fn stale_interior_map_renders_outdoor_when_outside() {
        use flatland_protocol::{InteriorMapView, InteriorRoomView};
        let building = BuildingView {
            id: "town_hall".into(),
            label: "Town Hall".into(),
            x: 163.0,
            y: 137.0,
            width_m: 20.0,
            depth_m: 10.0,
            interior_blueprint: Some("town_hall".into()),
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let mut state = state_with_building(building);
        state.interior_map = Some(InteriorMapView {
            building_id: "town_hall".into(),
            blueprint_id: "town_hall".into(),
            background_color: "#000000".into(),
            default_floor_color: Some("#2a2a2a".into()),
            floor_height_m: 3.0,
            z_platforms: vec![],
            z_transitions: vec![],
            rooms: vec![InteriorRoomView {
                id: "main_hall".into(),
                label: "Main".into(),
                floor: 0,
                x0: -3.5,
                y0: -8.0,
                x1: 18.5,
                y1: 6.0,
                floor_color: None,
                floor_glyph: None,
            }],
            room_doors: vec![],
        });
        state.player = state.entities.first().cloned();
        let view = WorldView::build_with_target(&state, 25, 15, None);
        assert!(view.inside_building.is_none());
        let flat = view.cells.join("");
        let grass = map_presentation::terrain_for(TerrainKindView::Grass).glyph;
        assert!(
            flat.contains(&grass),
            "expected outdoor terrain, not stale interior background: {flat}"
        );
        assert!(
            !flat.chars().all(|c| c == ' ' || c == '@'),
            "stale interior_map must not paint black interior when outside"
        );
    }

    #[test]
    fn stale_inside_flag_still_renders_outdoor_world() {
        use flatland_protocol::ResourceNodeState;
        let building = BuildingView {
            id: "broker_hut".into(),
            label: "Broker's Hut".into(),
            x: 148.0,
            y: 118.0,
            width_m: 8.0,
            depth_m: 6.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let mut state = state_with_building(building);
        state.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: Some(PlayerVitals::default()),
            attributes: Some(PrimaryAttributes::default()),
            skills: Some(flatland_protocol::PlayerSkills::default()),
            inside_building: Some("broker_hut".into()),
            tile_id: None,
            paperdoll_ref: None,
            presentation_state: None,
            sprite_mode: None,
            progression_xp: None,
            combat_cues: Vec::new(),
        }];
        state.player = state.entities.first().cloned();
        state
            .resource_nodes
            .push(flatland_protocol::ResourceNodeView {
                id: "oak".into(),
                label: "Oak".into(),
                x: 126.0,
                y: 134.0,
                z: 0.0,
                item_template: "oak_log".into(),
                state: ResourceNodeState::Available,
                blocking: true,
                blocking_radius_m: 0.8,
                tile_id: None,
                yaw: 0.0,
                pitch: 0.0,
                roll: 0.0,
                draw_scale: 1.0,
                sprite_mode: None,
                growth_progress: None,
                presentation_state: None,
            channel_start_tick: None,
            channel_end_tick: None,
            harvest_drop_templates: Vec::new(),});
        let view = WorldView::build_with_target(&state, 25, 15, None);
        assert_eq!(
            view.inside_building.as_deref(),
            Some("broker_hut"),
            "server inside flag is authoritative"
        );
        let flat = view.cells.join("");
        let oak = map_presentation::resource_for(&flatland_protocol::ResourceNodeView {
            id: "oak".into(),
            label: "Oak".into(),
            x: 0.0,
            y: 0.0,
            z: 0.0,
            item_template: "oak_log".into(),
            state: flatland_protocol::ResourceNodeState::Available,
            blocking: true,
            blocking_radius_m: 0.8,
            tile_id: None,
            yaw: 0.0,
            pitch: 0.0,
            roll: 0.0,
            draw_scale: 1.0,
            sprite_mode: None,
            growth_progress: None,
            presentation_state: None,
        channel_start_tick: None,
        channel_end_tick: None,
        harvest_drop_templates: Vec::new(),});
        assert!(
            flat.contains(&oak.glyph),
            "expected nearby tree ({:?}): {flat}",
            oak.glyph
        );
        assert!(flat.contains('@'), "expected player: {flat}");
    }

    #[test]
    fn inside_building_flag_selects_active_instance() {
        let town = BuildingView {
            id: "town_hall".into(),
            label: "Town Hall".into(),
            x: 160.0,
            y: 136.0,
            width_m: 20.0,
            depth_m: 10.0,
            interior_blueprint: Some("town_hall".into()),
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let guild = BuildingView {
            id: "guild_hall".into(),
            label: "Guild Hall".into(),
            x: 164.0,
            y: 152.0,
            width_m: 20.0,
            depth_m: 14.0,
            interior_blueprint: Some("guild_hall".into()),
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let mut state = state_with_building(town);
        state.buildings.push(guild);
        state.entities = vec![EntityState {
            id: 1,
            label: "You".into(),
            transform: Transform {
                position: WorldCoord::surface(4.0, 3.0),
                yaw: 0.0,
                velocity: flatland_protocol::Velocity2D { vx: 0.0, vy: 0.0 },
            },
            vitals: Some(PlayerVitals::default()),
            attributes: Some(PrimaryAttributes::default()),
            skills: Some(flatland_protocol::PlayerSkills::default()),
            inside_building: Some("guild_hall".into()),
            tile_id: None,
            paperdoll_ref: None,
            presentation_state: None,
            sprite_mode: None,
            progression_xp: None,
            combat_cues: Vec::new(),
        }];
        state.player = state.entities.first().cloned();
        state.world_width_m = 256.0;
        state.world_height_m = 256.0;

        let view = WorldView::build_with_target(&state, 25, 15, None);
        assert_eq!(view.inside_building.as_deref(), Some("guild_hall"));
    }

    #[test]
    fn combat_target_marks_creature_cell() {
        let building = BuildingView {
            id: "x".into(),
            label: "X".into(),
            x: 128.0,
            y: 128.0,
            width_m: 1.0,
            depth_m: 1.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let mut state = state_with_building(building);
        state.entities = vec![
            EntityState {
                id: 1,
                label: "You".into(),
                transform: Transform {
                    position: WorldCoord::surface(100.0, 100.0),
                    yaw: 0.0,
                    velocity: flatland_protocol::Velocity2D { vx: 0.0, vy: 0.0 },
                },
                vitals: Some(PlayerVitals::default()),
                attributes: Some(PrimaryAttributes::default()),
                skills: Some(flatland_protocol::PlayerSkills::default()),
                inside_building: None,
                tile_id: None,
                paperdoll_ref: None,
                presentation_state: None,
                sprite_mode: None,
                progression_xp: None,
                combat_cues: Vec::new(),
            },
            EntityState {
                id: 42,
                label: "Rabbit".into(),
                transform: Transform {
                    position: WorldCoord::surface(103.0, 100.0),
                    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,
                paperdoll_ref: None,
                presentation_state: None,
                sprite_mode: None,
                progression_xp: None,
                combat_cues: Vec::new(),
            },
        ];
        state.player = state.entities.first().cloned();
        state.combat_target = Some(42);
        state.combat_target_label = Some("Rabbit".into());

        let view = WorldView::build_with_target(&state, 25, 15, None);
        let marked: usize = view
            .target_t1_cells
            .iter()
            .chain(view.target_t2_cells.iter())
            .filter(|b| **b)
            .count();
        assert_eq!(marked, 1, "exactly one targeted cell");
        let idx = view
            .target_t1_cells
            .iter()
            .chain(view.target_t2_cells.iter())
            .position(|b| *b)
            .expect("target cell");
        assert_eq!(view.cells[idx], "R");
    }

    #[test]
    fn combat_target_ring_prefers_live_npc_coords() {
        let building = BuildingView {
            id: "x".into(),
            label: "X".into(),
            x: 128.0,
            y: 128.0,
            width_m: 1.0,
            depth_m: 1.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        };
        let mut state = state_with_building(building);
        state.entities = vec![
            EntityState {
                id: 1,
                label: "You".into(),
                transform: Transform {
                    position: WorldCoord::surface(100.0, 100.0),
                    yaw: 0.0,
                    velocity: flatland_protocol::Velocity2D { vx: 0.0, vy: 0.0 },
                },
                vitals: Some(PlayerVitals::default()),
                attributes: Some(PrimaryAttributes::default()),
                skills: Some(flatland_protocol::PlayerSkills::default()),
                inside_building: None,
                tile_id: None,
                paperdoll_ref: None,
                presentation_state: None,
                sprite_mode: None,
                progression_xp: None,
                combat_cues: Vec::new(),
            },
            EntityState {
                id: 42,
                label: "Rabbit".into(),
                // Stale entity transform — NPC view has the live position.
                transform: Transform {
                    position: WorldCoord::surface(90.0, 100.0),
                    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,
                paperdoll_ref: None,
                presentation_state: None,
                sprite_mode: None,
                progression_xp: None,
                combat_cues: Vec::new(),
            },
        ];
        state.npcs = vec![flatland_protocol::NpcView {
            id: "rabbit-1".into(),
            label: "Rabbit".into(),
            role: "wildlife".into(),
            x: 103.0,
            y: 100.0,
            building_id: None,
            entity_id: Some(42),
            life_state: Some(flatland_protocol::LifeState::Alive),
            hp_pct: Some(1.0),
            can_trade: false,
            tile_id: None,
            behavior_state: None,
            presentation_state: None,
            sprite_mode: None,
            paperdoll_ref: None,
        }];
        state.player = state.entities.first().cloned();
        state.combat_target = Some(42);

        let view = WorldView::build_with_target(&state, 25, 15, None);
        let marked = view
            .target_t1_cells
            .iter()
            .position(|b| *b)
            .expect("target cell");
        let half_w = (view.width / 2) as i32;
        let half_h = (view.height / 2) as i32;
        let (live_gx, live_gy) =
            world_to_grid(103.0, 100.0, 100.0, 100.0, half_w, half_h, view.width, view.height)
                .expect("live npc in view");
        let (stale_gx, stale_gy) =
            world_to_grid(90.0, 100.0, 100.0, 100.0, half_w, half_h, view.width, view.height)
                .expect("stale entity in view");
        let live_idx = live_gy * view.width + live_gx;
        let stale_idx = stale_gy * view.width + stale_gx;
        assert_eq!(marked, live_idx, "ring must follow live NPC coords");
        assert_ne!(marked, stale_idx, "ring must not stay on stale entity coords");
    }

    #[test]
    fn grid_to_world_roundtrips_center() {
        let px = 10.0;
        let py = 20.0;
        let view_w = 11;
        let view_h = 11;
        let half_w = (view_w / 2) as i32;
        let half_h = (view_h / 2) as i32;
        let (gx, gy) =
            world_to_grid(12.0, 18.0, px, py, half_w, half_h, view_w, view_h).expect("in view");
        let (wx, wy) = grid_to_world(gx, gy, px, py, view_w, view_h).expect("inverse");
        assert!((wx - 12.0).abs() < 0.01);
        assert!((wy - 18.0).abs() < 0.01);
    }

    #[test]
    fn vertical_axis_quantizes_to_one_meter() {
        let px = 0.0;
        let py = 0.0;
        let view_w = 21;
        let view_h = 21;
        let half_w = (view_w / 2) as i32;
        let half_h = (view_h / 2) as i32;
        let (gx, gy) =
            world_to_grid(3.0, 3.0, px, py, half_w, half_h, view_w, view_h).expect("in view");
        let (wx, wy) = grid_to_world(gx, gy, px, py, view_w, view_h).expect("inverse");
        assert!(
            (wx - 3.0).abs() < 0.01,
            "x should stay exact to 1m: got {wx}"
        );
        assert!(
            (wy - 3.0).abs() < 0.01,
            "y should stay exact to 1m: got {wy}"
        );
    }

    #[test]
    fn square_extent_spans_equal_rows_and_columns() {
        let px = 0.0;
        let py = 0.0;
        let half_w = 50;
        let half_h = 50;
        let width = 101;
        let height = 101;
        let (gx0, gy0) =
            world_to_grid(-4.0, -4.0, px, py, half_w, half_h, width, height).expect("in view");
        let (gx1, gy1) =
            world_to_grid(4.0, 4.0, px, py, half_w, half_h, width, height).expect("in view");
        let cols_spanned = (gx1 as i32 - gx0 as i32).unsigned_abs();
        let rows_spanned = (gy1 as i32 - gy0 as i32).unsigned_abs();
        assert_eq!(cols_spanned, 8, "8m wide should span 8 columns");
        assert_eq!(rows_spanned, 8, "8m tall should span 8 rows");
    }

    #[test]
    fn resource_paints_on_terrain_cell_for_same_world_coords() {
        use flatland_protocol::{ResourceNodeState, ResourceNodeView, TerrainZoneView};

        let px = 128.0;
        let py = 128.0;
        let rx = 131.0;
        let ry = 132.0;
        let mut state = state_with_building(BuildingView {
            id: "x".into(),
            label: "X".into(),
            x: 128.0,
            y: 128.0,
            width_m: 1.0,
            depth_m: 1.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        });
        state.terrain_zones.push(TerrainZoneView {
            id: "pond".into(),
            x0: rx,
            y0: ry,
            x1: rx + 1.0,
            y1: ry + 1.0,
            kind: TerrainKindView::ShallowWater,
            elevation: -0.5,
            glyph: None,
            color: None,
            tile_id: None,
            z_order: 0,
            channel_start_tick: None,
            channel_end_tick: None,
        });
        state.resource_nodes.push(ResourceNodeView {
            id: "oak".into(),
            label: "Oak".into(),
            x: rx,
            y: ry,
            z: 0.0,
            item_template: "oak_log".into(),
            state: ResourceNodeState::Available,
            blocking: true,
            blocking_radius_m: 0.8,
            tile_id: None,
            yaw: 0.0,
            pitch: 0.0,
            roll: 0.0,
            draw_scale: 1.0,
            sprite_mode: None,
            growth_progress: None,
            presentation_state: None,
        channel_start_tick: None,
        channel_end_tick: None,
        harvest_drop_templates: Vec::new(),});
        state.entities[0].transform.position = WorldCoord::surface(px, py);
        state.player = state.entities.first().cloned();

        let view = WorldView::build_with_target(&state, 25, 15, None);
        let half_w = (view.width / 2) as i32;
        let half_h = (view.height / 2) as i32;
        let (gx, gy) = world_to_grid(rx, ry, px, py, half_w, half_h, view.width, view.height)
            .expect("resource in view");
        let idx = gy * view.width + gx;
        let oak = map_presentation::resource_for(&state.resource_nodes[0]);
        assert_eq!(
            view.cells[idx], oak.glyph,
            "resource should paint on the grid cell for its world coords"
        );
        let (wx, wy) = grid_to_world(gx, gy, px, py, view.width, view.height).expect("inverse");
        assert!(
            (wx - rx).abs() < 0.01 && (wy - ry).abs() < 0.01,
            "resource grid cell should sample terrain at ({wx}, {wy}), expected ({rx}, {ry})"
        );
    }

    #[test]
    fn chest_and_loot_paint_on_non_grass_terrain() {
        use flatland_protocol::{GroundDropView, PlacedContainerView, TerrainZoneView};

        let px = 50.0;
        let py = 50.0;
        let cx = 53.0;
        let cy = 52.0;
        let lx = 54.0;
        let ly = 52.0;
        let mut state = state_with_building(BuildingView {
            id: "x".into(),
            label: "X".into(),
            x: 50.0,
            y: 50.0,
            width_m: 1.0,
            depth_m: 1.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        });
        state.terrain_zones.push(TerrainZoneView {
            id: "trail".into(),
            x0: 52.0,
            y0: 51.0,
            x1: 56.0,
            y1: 54.0,
            kind: TerrainKindView::Trail,
            elevation: 0.0,
            glyph: None,
            color: None,
            tile_id: None,
            z_order: 0,
            channel_start_tick: None,
            channel_end_tick: None,
        });
        state.placed_containers.push(PlacedContainerView {
            id: "chest_1".into(),
            template_id: "wood_chest".into(),
            display_name: "Storage".into(),
            x: cx,
            y: cy,
            z: 0.0,
            locked: false,
            accessible: true,
            owner_character_id: None,
            contents: vec![],
            lock_id: None,
            capacity_volume: Some(40.0),
            item_instance_id: None,
            tile_id: None,
            worker_lodging_capacity: None,
        blocking: true,
        blocking_radius_m: 0.8,});
        state.ground_drops.push(GroundDropView {
            id: "drop_1".into(),
            template_id: "lumber".into(),
            quantity: 2,
            x: lx,
            y: ly,
            z: 0.0,
            tile_id: None,
            display_name: None,
            yaw: 0.0,
            pitch: 0.0,
            roll: 0.0,
            draw_scale: 1.0,
        });
        state.entities[0].transform.position = WorldCoord::surface(px, py);
        state.player = state.entities.first().cloned();

        let view = WorldView::build_with_target(&state, 25, 15, None);
        let half_w = (view.width / 2) as i32;
        let half_h = (view.height / 2) as i32;
        let (gx, gy) =
            world_to_grid(cx, cy, px, py, half_w, half_h, view.width, view.height).expect("chest");
        let chest = map_presentation::chest_presentation(false);
        assert_eq!(
            view.cells[gy * view.width + gx],
            chest.glyph,
            "chest must paint on trail/non-grass cells"
        );
        let (gx2, gy2) =
            world_to_grid(lx, ly, px, py, half_w, half_h, view.width, view.height).expect("loot");
        let loot = map_presentation::loot_presentation();
        assert_eq!(
            view.cells[gy2 * view.width + gx2],
            loot.glyph,
            "ground loot must paint on trail/non-grass cells"
        );
    }

    #[test]
    fn build_with_anchor_sets_view_origin() {
        let mut state = state_with_building(BuildingView {
            id: "x".into(),
            label: "X".into(),
            x: 128.0,
            y: 128.0,
            width_m: 1.0,
            depth_m: 1.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        });
        state.entities[0].transform.position = WorldCoord::surface(100.0, 200.0);
        state.player = state.entities.first().cloned();
        let view = WorldView::build_with_anchor(
            &state,
            21,
            15,
            12.3,
            40.7,
            None,
            WorldViewOptions::terrain_only(),
        );
        assert!((view.origin_x - 12.3).abs() < 0.01);
        assert!((view.origin_y - 40.7).abs() < 0.01);
    }

    #[test]
    fn skip_local_player_glyph_when_paint_local_player_false() {
        let mut state = state_with_building(BuildingView {
            id: "x".into(),
            label: "X".into(),
            x: 10.0,
            y: 10.0,
            width_m: 1.0,
            depth_m: 1.0,
            interior_blueprint: None,
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        });
        state.entities[0].transform.position = WorldCoord::surface(128.0, 128.0);
        state.player = state.entities.first().cloned();
        let player_glyph = map_presentation::player_presentation().glyph;

        let with_player =
            WorldView::build_with_options(&state, 21, 15, None, WorldViewOptions::default());
        let cx = with_player.width / 2;
        let cy = with_player.height / 2;
        assert_eq!(
            with_player.cells[cy * with_player.width + cx],
            player_glyph,
            "default build paints @"
        );

        let without =
            WorldView::build_with_options(&state, 21, 15, None, WorldViewOptions::terrain_only());
        assert_ne!(
            without.cells[cy * without.width + cx],
            player_glyph,
            "gfx sprite mode must not paint local player @"
        );
    }

    fn town_hall_state(px: f32, py: f32) -> GameState {
        use flatland_protocol::{InteriorMapView, InteriorRoomView};
        let mut state = state_with_building(BuildingView {
            id: "town_hall".into(),
            label: "Town Hall".into(),
            x: 156.0,
            y: 153.0,
            width_m: 20.0,
            depth_m: 9.0,
            interior_blueprint: Some("town_hall".into()),
            tags: vec![],
            market_boundary_zone_ids: vec![],
            market_max_volume: None,
            wall_set: None,
            roof_set: None,
        });
        state.interior_map = Some(InteriorMapView {
            building_id: "town_hall".into(),
            blueprint_id: "town_hall".into(),
            background_color: "#000".into(),
            default_floor_color: Some("#2a2a2a".into()),
            floor_height_m: 3.0,
            z_platforms: vec![],
            z_transitions: vec![],
            rooms: vec![
                InteriorRoomView { id: "main".into(), label: "Main".into(), floor: 0, x0: -3.5, y0: -8.0, x1: 18.5, y1: 6.0, floor_color: None, floor_glyph: None },
                InteriorRoomView { id: "kitchen".into(), label: "Kitchen".into(), floor: 0, x0: 18.5, y0: -8.0, x1: 23.5, y1: 0.0, floor_color: None, floor_glyph: None },
                InteriorRoomView { id: "weapon".into(), label: "Weapon".into(), floor: 0, x0: 18.5, y0: 0.0, x1: 25.5, y1: 12.5, floor_color: None, floor_glyph: None },
                InteriorRoomView { id: "hall_n".into(), label: "Hall N".into(), floor: 0, x0: -3.5, y0: 6.0, x1: 12.0, y1: 12.5, floor_color: None, floor_glyph: None },
                InteriorRoomView { id: "meeting".into(), label: "Meeting".into(), floor: 0, x0: -3.5, y0: 12.5, x1: 12.0, y1: 23.5, floor_color: None, floor_glyph: None },
                InteriorRoomView { id: "office".into(), label: "Office".into(), floor: 0, x0: 12.0, y0: 6.0, x1: 18.5, y1: 12.5, floor_color: None, floor_glyph: None },
            ],
            room_doors: vec![],
        });
        state.entities[0].transform.position = WorldCoord::surface(px, py);
        state.entities[0].inside_building = Some("town_hall".into());
        state.player = state.entities.first().cloned();
        state
    }

    /// Outer perimeter walls (east/south edges at half-meter coords) must paint even
    /// when the wall glyph cell sits outside every room's floor fill (background void).
    #[test]
    fn outer_perimeter_walls_render_at_positive_anchor() {
        let state = town_hall_state(20.0, 6.0);
        let view = WorldView::build_with_anchor(
            &state,
            31,
            31,
            20.0,
            6.0,
            None,
            WorldViewOptions::terrain_only(),
        );
        let cell = |x: i32, y: i32| {
            let (gx, gy) =
                world_to_grid(x as f32, y as f32, 20.0, 6.0, 15, 15, view.width, view.height)
                    .expect("in view");
            view.cells[gy * view.width + gx].clone()
        };
        // Weapon shack east wall (x=25.5 → glyph col 26) on a mid-room row and at the
        // top-wall corner (row 13) — the corner cell is background void otherwise.
        assert!(is_wall(&cell(26, 9)), "weapon east wall at (26,9): {}", cell(26, 9));
        assert!(
            cell(26, 13) == "+" || cell(26, 13) == "-" || cell(26, 13) == "|",
            "top wall east corner (26,13): {}",
            cell(26, 13)
        );
        // Small office east wall (x=18.5 → glyph col 19) on a mid-row.
        assert!(is_wall(&cell(19, 9)), "office east wall at (19,9): {}", cell(19, 9));
        // Kitchen east wall (x=23.5 → glyph col 24) on a mid-row.
        assert!(is_wall(&cell(24, -4)), "kitchen east wall at (24,-4): {}", cell(24, -4));
        // Bottom wall spans the merged kitchen+main hall width incl. the kitchen east corner.
        assert!(
            cell(24, -8) == "+" || cell(24, -8) == "-" || cell(24, -8) == "|",
            "bottom wall kitchen-east corner (24,-8): {}",
            cell(24, -8)
        );
        // Top wall spans the full merged width to the weapon east corner (x=26, row 13).
        assert!(
            cell(12, 13) == "+" || cell(12, 13) == "-" || cell(12, 13) == "|",
            "top wall at (12,13): {}",
            cell(12, 13)
        );
    }
}