cuqueclicker 0.3.0

use std::collections::{HashMap, HashSet};

use ratatui::layout::Rect;
use serde::{Deserialize, Serialize};

use crate::game::achievement::ACHIEVEMENTS;
use crate::game::fingerer::{self, FINGERERS};
use crate::game::golden::GoldenCuque;
use crate::game::upgrade::{UPGRADES, UpgradeEffect};

pub const TICK_HZ: u32 = 20;
pub const TICK_DT: f64 = 1.0 / TICK_HZ as f64;
const CLENCH_TICKS: u32 = 3;
const PARTICLE_LIFE: u32 = 20;
/// Per-tick upward drift for a particle, expressed as a fraction of the
/// biscuit's height. Calibrated to match the original feel before the
/// switch to fractional anchors: the old code rose 0.18 cells/tick on
/// any biscuit size; on a typical ~30-row biscuit that's 0.006 of height
/// per tick — slow enough that a "+1" only travels ~10-12% of the biscuit
/// across its 1-second life, instead of streaking across half of it.
const PARTICLE_FRAC_RISE: f32 = 0.006;
const GOLDEN_REWARD_SECONDS: f64 = 60.0;
const GOLDEN_REWARD_FLAT: f64 = 10.0;

/// Position is stored as a fraction of the biscuit rect ([0.0, 1.0] on each
/// axis), matching `GoldenCuque`. The renderer resolves these fractions
/// against the *current* biscuit rect every frame, so particles travel with
/// the biscuit when the terminal resizes or the user zooms.
#[derive(Clone)]
pub struct Particle {
    pub frac_x: f32,
    pub frac_y: f32,
    pub life: u32,
    pub text: String,
}

/// Convert an absolute `(col, row)` screen point into biscuit-fractional
/// coordinates, clamped to [0.0, 1.0]. Used at click/spawn sites that come
/// from screen-space input (mouse clicks, RNG within the biscuit rect).
pub fn screen_to_biscuit_frac(col: u16, row: u16, biscuit: Rect) -> (f32, f32) {
    if biscuit.width == 0 || biscuit.height == 0 {
        return (0.5, 0.5);
    }
    let fx = ((col as i32 - biscuit.x as i32) as f32) / biscuit.width as f32;
    let fy = ((row as i32 - biscuit.y as i32) as f32) / biscuit.height as f32;
    (fx.clamp(0.0, 1.0), fy.clamp(0.0, 1.0))
}

/// Convert biscuit-fractional coordinates back to an absolute screen point.
pub fn biscuit_frac_to_screen(frac_x: f32, frac_y: f32, biscuit: Rect) -> (u16, u16) {
    let col = biscuit.x as f32 + frac_x.clamp(0.0, 1.0) * biscuit.width as f32;
    let row = biscuit.y as f32 + frac_y.clamp(0.0, 1.0) * biscuit.height as f32;
    (
        col.round().clamp(0.0, u16::MAX as f32) as u16,
        row.round().clamp(0.0, u16::MAX as f32) as u16,
    )
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub enum Buff {
    ClickFrenzy {
        ticks_remaining: u32,
        initial_ticks: u32,
        mult: f64,
    },
    /// Fingerer mult buff — applied when a "Buff" golden variant is caught.
    /// Targets a fingerer by stable id so the buff stays on the right tier
    /// across catalog changes.
    FingererBoost {
        ticks_remaining: u32,
        initial_ticks: u32,
        fingerer_id: String,
        mult: f64,
    },
}

impl Buff {
    pub fn ticks_remaining(&self) -> u32 {
        match self {
            Buff::ClickFrenzy {
                ticks_remaining, ..
            } => *ticks_remaining,
            Buff::FingererBoost {
                ticks_remaining, ..
            } => *ticks_remaining,
        }
    }

    /// Plateau-at-1.0 until the last `BUFF_FADE_TICKS` of the buff, then
    /// smoothstep-decay to 0. Gives a "stays on, then swift but smooth fade"
    /// feel rather than a constantly-shrinking linear ramp.
    pub fn strength(&self) -> f32 {
        const FADE_TICKS: f32 = 30.0; // ~1.5s at 20Hz
        let remaining = self.ticks_remaining() as f32;
        if remaining >= FADE_TICKS {
            1.0
        } else {
            let t = (remaining / FADE_TICKS).clamp(0.0, 1.0);
            t * t * (3.0 - 2.0 * t)
        }
    }

    fn tick(&mut self) {
        match self {
            Buff::ClickFrenzy {
                ticks_remaining, ..
            } => {
                *ticks_remaining = ticks_remaining.saturating_sub(1);
            }
            Buff::FingererBoost {
                ticks_remaining, ..
            } => {
                *ticks_remaining = ticks_remaining.saturating_sub(1);
            }
        }
    }
}

/// Persistent game state. Catalog-addressed state (`fingerers_owned`,
/// `upgrades_earned`, `achievements_earned`) is keyed by STABLE STRING IDS,
/// not positional indices, so reordering / inserting / removing entries in
/// `FINGERERS`, `UPGRADES`, or `ACHIEVEMENTS` never corrupts an old save.
/// Unknown ids in a save are ignored (forward-compat); missing ids default
/// to zero / absent (backward-compat).
#[derive(Clone, Serialize, Deserialize)]
pub struct GameState {
    #[serde(default)]
    pub cuques: f64,
    #[serde(default)]
    pub total_clicks: u64,
    #[serde(default)]
    pub lifetime_cuques: f64,
    #[serde(default)]
    pub best_fps: f64,
    #[serde(default)]
    pub golden_caught: u64,

    /// Fingerer id → owned count.
    #[serde(default)]
    pub fingerers_owned: HashMap<String, u32>,
    /// Set of earned achievement ids.
    #[serde(default)]
    pub achievements_earned: HashSet<String>,
    /// Set of earned upgrade ids.
    #[serde(default)]
    pub upgrades_earned: HashSet<String>,

    #[serde(default)]
    pub prestige: u64,
    #[serde(default)]
    pub total_play_ticks: u64,
    #[serde(default)]
    pub buffs: Vec<Buff>,

    #[serde(skip)]
    pub clench_ticks: u32,
    #[serde(skip)]
    pub particles: Vec<Particle>,
    #[serde(skip)]
    pub golden: Option<GoldenCuque>,
    #[serde(skip)]
    pub golden_cooldown: u32,
    #[serde(skip)]
    pub session_ticks: u64,
    /// Achievement ids that unlocked this session; drained by the UI after
    /// it shows the "unlocked!" toast.
    #[serde(skip)]
    pub newly_unlocked: Vec<String>,
    #[serde(skip)]
    pub visual_debt: f64,
    #[serde(skip)]
    pub lucky_flash_ticks: u32,
    #[serde(skip)]
    pub border_phase: u32,
    #[serde(skip)]
    pub purchase_flash_ticks: u32,
    /// One slot per visible sidebar row; indexed by catalog position because
    /// it's purely a render-time flash and doesn't need to survive reorders.
    #[serde(skip)]
    pub fingerer_flash_ticks: Vec<u32>,
}

pub const LUCKY_FLASH_TICKS: u32 = 70; // 3.5s at 20Hz
pub const PURCHASE_FLASH_TICKS: u32 = 20; // 1s at 20Hz

impl Default for GameState {
    fn default() -> Self {
        Self {
            cuques: 0.0,
            total_clicks: 0,
            lifetime_cuques: 0.0,
            best_fps: 0.0,
            golden_caught: 0,
            fingerers_owned: HashMap::new(),
            achievements_earned: HashSet::new(),
            upgrades_earned: HashSet::new(),
            prestige: 0,
            total_play_ticks: 0,
            buffs: Vec::new(),
            clench_ticks: 0,
            particles: Vec::new(),
            golden: None,
            golden_cooldown: crate::game::golden::next_cooldown(),
            session_ticks: 0,
            newly_unlocked: Vec::new(),
            visual_debt: 0.0,
            lucky_flash_ticks: 0,
            border_phase: 0,
            purchase_flash_ticks: 0,
            fingerer_flash_ticks: vec![0; fingerer::count()],
        }
    }
}

impl GameState {
    /// Initialize ephemeral runtime state that `#[serde(skip)]` left empty
    /// after deserialization, and normalize any fields that need live values
    /// rather than the serde default. Hook point for future shape
    /// transforms — see CLAUDE.md on the stable-id save policy.
    pub fn migrate(mut self) -> Self {
        if self.fingerer_flash_ticks.len() != fingerer::count() {
            self.fingerer_flash_ticks = vec![0; fingerer::count()];
        }
        if self.golden_cooldown == 0 {
            self.golden_cooldown = crate::game::golden::next_cooldown();
        }
        self
    }

    // -- Catalog lookups (stable-id keyed) ---------------------------------

    pub fn fingerer_count(&self, id: &str) -> u32 {
        self.fingerers_owned.get(id).copied().unwrap_or(0)
    }

    pub fn fingerer_count_idx(&self, idx: usize) -> u32 {
        FINGERERS
            .get(idx)
            .map(|f| self.fingerer_count(f.id))
            .unwrap_or(0)
    }

    pub fn fingerers_owned_total(&self) -> u32 {
        self.fingerers_owned.values().sum()
    }

    pub fn has_upgrade(&self, id: &str) -> bool {
        self.upgrades_earned.contains(id)
    }

    pub fn has_achievement(&self, id: &str) -> bool {
        self.achievements_earned.contains(id)
    }

    pub fn has_achievement_idx(&self, idx: usize) -> bool {
        ACHIEVEMENTS
            .get(idx)
            .is_some_and(|a| self.has_achievement(a.id))
    }

    // -- Click / tick -------------------------------------------------------

    pub fn click(&mut self, origin: (u16, u16), biscuit: Rect) {
        let power = self.click_power();
        self.add_cuques(power);
        self.total_clicks += 1;
        self.clench_ticks = CLENCH_TICKS;
        let jitter = (self.total_clicks as i32 % 9) - 4;
        let col = (origin.0 as i32 + jitter).max(0) as u16;
        let row = origin.1.saturating_sub(1);
        let (frac_x, frac_y) = screen_to_biscuit_frac(col, row, biscuit);
        self.particles.push(Particle {
            frac_x,
            frac_y,
            life: PARTICLE_LIFE,
            text: format!("+{}", crate::format::big(power)),
        });
    }

    pub fn click_power(&self) -> f64 {
        let mut m = 1.0;
        for u in UPGRADES.iter() {
            if self.has_upgrade(u.id)
                && let UpgradeEffect::ClickMult(f) = u.effect
            {
                m *= f;
            }
        }
        for b in &self.buffs {
            if let Buff::ClickFrenzy { mult, .. } = b {
                m *= *mult;
            }
        }
        m
    }

    pub fn fingerer_mult(&self, idx: usize) -> f64 {
        let Some(target) = FINGERERS.get(idx) else {
            return 1.0;
        };
        let mut m = 1.0;
        for u in UPGRADES.iter() {
            if !self.has_upgrade(u.id) {
                continue;
            }
            match u.effect {
                UpgradeEffect::FingererMult(id, f) if id == target.id => m *= f,
                UpgradeEffect::AllFingerersMult(f) => m *= f,
                _ => {}
            }
        }
        for b in &self.buffs {
            if let Buff::FingererBoost {
                fingerer_id, mult, ..
            } = b
                && fingerer_id == target.id
            {
                m *= *mult;
            }
        }
        m
    }

    fn add_cuques(&mut self, amount: f64) {
        self.cuques += amount;
        self.lifetime_cuques += amount;
    }

    /// Dev-build cheat. Bypasses normal flow; not reachable in release builds
    /// because the F-key that triggers it is gated behind `App::debug`.
    pub fn dev_add_cuques(&mut self, amount: f64) {
        self.add_cuques(amount);
    }

    /// Catch whatever Golden Cuque is currently on screen (any variant:
    /// Lucky, Frenzy, or Buff). Applies the variant-specific effect,
    /// increments `golden_caught`, re-rolls the next spawn cooldown, and
    /// returns the flat reward (0.0 for buff variants).
    pub fn catch_golden(&mut self) -> f64 {
        use crate::game::golden::GoldenVariant;
        let Some(golden) = self.golden.take() else {
            return 0.0;
        };
        self.golden_caught += 1;
        self.golden_cooldown = crate::game::golden::next_cooldown();
        let (reward, label) = match golden.variant {
            GoldenVariant::Lucky => {
                let fps = self.fps();
                let r = (fps * GOLDEN_REWARD_SECONDS).max(GOLDEN_REWARD_FLAT);
                self.add_cuques(r);
                self.lucky_flash_ticks = LUCKY_FLASH_TICKS;
                (r, format!("+{}", crate::format::big(r)))
            }
            GoldenVariant::Frenzy => {
                let dur = TICK_HZ * 13;
                self.buffs.push(Buff::ClickFrenzy {
                    ticks_remaining: dur,
                    initial_ticks: dur,
                    mult: 777.0,
                });
                (0.0, "FRENZY x777!".into())
            }
            GoldenVariant::Buff => {
                let active_ids: Vec<&'static str> = FINGERERS
                    .iter()
                    .filter(|f| self.fingerer_count(f.id) > 0)
                    .map(|f| f.id)
                    .collect();
                let pick = if active_ids.is_empty() {
                    FINGERERS[0].id
                } else {
                    use rand::RngExt;
                    active_ids[rand::rng().random_range(0..active_ids.len())]
                };
                let dur = TICK_HZ * 60;
                self.buffs.push(Buff::FingererBoost {
                    ticks_remaining: dur,
                    initial_ticks: dur,
                    fingerer_id: pick.to_string(),
                    mult: 7.0,
                });
                (0.0, "BOOSTED x7!".into())
            }
        };
        self.particles.push(Particle {
            frac_x: golden.frac_x,
            frac_y: golden.frac_y,
            life: PARTICLE_LIFE * 2,
            text: label,
        });
        reward
    }

    pub fn fps(&self) -> f64 {
        let base: f64 = FINGERERS
            .iter()
            .enumerate()
            .map(|(i, k)| k.fps_per_unit * self.fingerer_count(k.id) as f64 * self.fingerer_mult(i))
            .sum();
        base * self.prestige_mult()
    }

    pub fn border_speed(&self) -> u32 {
        let mut s: u32 = 1;
        for b in &self.buffs {
            match b {
                Buff::ClickFrenzy { .. } => s = s.max(3),
                Buff::FingererBoost { .. } => s = s.max(2),
            }
        }
        if self.lucky_flash_ticks > 0 {
            s = s.max(4);
        }
        if self.purchase_flash_ticks > 0 {
            s += 2;
        }
        s
    }

    pub fn trigger_purchase_flash(&mut self) {
        self.purchase_flash_ticks = PURCHASE_FLASH_TICKS;
    }

    pub fn prestige_mult(&self) -> f64 {
        1.0 + 0.01 * self.prestige as f64
    }

    pub fn prestige_earned_total(&self) -> u64 {
        (self.lifetime_cuques / 1_000_000.0).sqrt().floor() as u64
    }

    pub fn prestige_available(&self) -> u64 {
        self.prestige_earned_total().saturating_sub(self.prestige)
    }

    pub fn prestige_reset(&mut self) -> bool {
        let available = self.prestige_available();
        if available == 0 {
            return false;
        }
        self.prestige = self.prestige_earned_total();
        self.cuques = 0.0;
        self.fingerers_owned.clear();
        self.upgrades_earned.clear();
        self.buffs.clear();
        self.visual_debt = 0.0;
        self.particles.clear();
        self.golden = None;
        self.clench_ticks = 0;
        self.golden_cooldown = crate::game::golden::next_cooldown();
        true
    }

    pub fn tick(&mut self) {
        for b in self.buffs.iter_mut() {
            b.tick();
        }
        self.buffs.retain(|b| b.ticks_remaining() > 0);

        self.lucky_flash_ticks = self.lucky_flash_ticks.saturating_sub(1);
        self.purchase_flash_ticks = self.purchase_flash_ticks.saturating_sub(1);
        for t in self.fingerer_flash_ticks.iter_mut() {
            *t = t.saturating_sub(1);
        }
        let speed = self.border_speed();
        self.border_phase = self.border_phase.wrapping_add(speed);

        let fps = self.fps();
        if fps > self.best_fps {
            self.best_fps = fps;
        }
        let gained = fps * TICK_DT;
        self.add_cuques(gained);
        self.visual_debt += gained;
        self.clench_ticks = self.clench_ticks.saturating_sub(1);
        for p in self.particles.iter_mut() {
            p.life = p.life.saturating_sub(1);
            p.frac_y -= PARTICLE_FRAC_RISE;
        }
        self.particles.retain(|p| p.life > 0);
        self.session_ticks += 1;
        self.total_play_ticks += 1;
        self.tick_achievements();
    }

    pub fn tick_achievements(&mut self) {
        for a in ACHIEVEMENTS.iter() {
            if !self.has_achievement(a.id) && (a.unlocked)(self) {
                self.achievements_earned.insert(a.id.to_string());
                self.newly_unlocked.push(a.id.to_string());
            }
        }
    }

    pub fn tick_golden(&mut self) {
        if let Some(g) = self.golden.as_mut() {
            if g.life_ticks == 0 {
                self.golden = None;
                self.golden_cooldown = crate::game::golden::next_cooldown();
            } else {
                g.life_ticks -= 1;
            }
        } else if self.golden_cooldown > 0 {
            self.golden_cooldown -= 1;
        }
    }

    pub fn trigger_clench(&mut self) {
        self.clench_ticks = CLENCH_TICKS;
    }

    /// Spawn a "+N" particle representing cuques earned since the last
    /// auto-particle. Silently skips if there isn't a whole cuque of accrued
    /// income to show — at low FPS the caller is a rate-based timer that
    /// fires faster than cuques arrive, and spawning a "+1" in that window
    /// used to lie (particle flying up while the HUD counter didn't move).
    /// The shown amount is always real cuques that just accrued into
    /// `visual_debt`.
    pub fn spawn_auto_particle(&mut self, frac_x: f32, frac_y: f32) {
        let amount = self.visual_debt.floor() as u64;
        if amount == 0 {
            return;
        }
        self.visual_debt -= amount as f64;
        self.particles.push(Particle {
            frac_x,
            frac_y,
            life: PARTICLE_LIFE,
            text: format!("+{}", crate::format::big(amount as f64)),
        });
    }

    pub fn cost(&self, idx: usize) -> f64 {
        let k = &FINGERERS[idx];
        k.base_cost * k.cost_scale.powi(self.fingerer_count_idx(idx) as i32)
    }

    pub fn can_buy(&self, idx: usize) -> bool {
        self.cuques >= self.cost(idx)
    }

    pub fn buy(&mut self, idx: usize) -> bool {
        let c = self.cost(idx);
        if self.cuques >= c
            && let Some(f) = FINGERERS.get(idx)
        {
            self.cuques -= c;
            *self.fingerers_owned.entry(f.id.to_string()).or_insert(0) += 1;
            self.trigger_purchase_flash();
            if let Some(slot) = self.fingerer_flash_ticks.get_mut(idx) {
                *slot = PURCHASE_FLASH_TICKS;
            }
            true
        } else {
            false
        }
    }

    pub fn buy_n(&mut self, idx: usize, n: u32) -> u32 {
        let mut bought = 0;
        for _ in 0..n {
            if !self.buy(idx) {
                break;
            }
            bought += 1;
        }
        bought
    }

    pub fn buy_max(&mut self, idx: usize) -> u32 {
        let mut bought = 0;
        while self.buy(idx) {
            bought += 1;
        }
        bought
    }

    pub fn buy_upgrade(&mut self, idx: usize) -> bool {
        let Some(u) = UPGRADES.get(idx) else {
            return false;
        };
        if self.has_upgrade(u.id) {
            return false;
        }
        if !u.req.met(self) || self.cuques < u.cost {
            return false;
        }
        self.cuques -= u.cost;
        self.upgrades_earned.insert(u.id.to_string());
        self.trigger_purchase_flash();
        true
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn migrate_is_idempotent_on_current_shape() {
        let state = GameState {
            fingerers_owned: [("index_finger".to_string(), 9)].into_iter().collect(),
            upgrades_earned: ["click_mult_1".to_string()].into_iter().collect(),
            achievements_earned: ["first_finger".to_string()].into_iter().collect(),
            ..GameState::default()
        };

        let m = state.migrate();

        assert_eq!(m.fingerer_count("index_finger"), 9);
        assert!(m.has_upgrade("click_mult_1"));
        assert!(m.has_achievement("first_finger"));
    }

    #[test]
    fn unknown_ids_in_save_are_ignored_not_resurrected() {
        // Forward-compat: a future version adds `"giga_finger"` to the
        // catalog, player plays, saves. User downgrades to current version.
        // That unknown id must not crash — it just reads as 0.
        let state = GameState {
            fingerers_owned: [("giga_finger_from_the_future".to_string(), 42)]
                .into_iter()
                .collect(),
            ..GameState::default()
        };

        let m = state.migrate();

        assert_eq!(m.fingerer_count("giga_finger_from_the_future"), 42);
        assert_eq!(m.fingerer_count("index_finger"), 0);
        assert!(!m.has_upgrade("click_mult_1"));
    }

    #[test]
    fn save_roundtrip_is_stable_through_json() {
        // Serialize → deserialize → get the same state back. Catches any
        // accidental rename that would make saves non-idempotent.
        let state = GameState {
            cuques: 1234.5,
            total_clicks: 99,
            fingerers_owned: [("index_finger".to_string(), 7)].into_iter().collect(),
            upgrades_earned: ["click_mult_1".to_string()].into_iter().collect(),
            achievements_earned: ["first_finger".to_string()].into_iter().collect(),
            ..GameState::default()
        };

        let json = serde_json::to_string(&state).expect("serialize");
        let roundtripped: GameState = serde_json::from_str(&json).expect("deserialize");
        let m = roundtripped.migrate();

        assert_eq!(m.cuques, 1234.5);
        assert_eq!(m.total_clicks, 99);
        assert_eq!(m.fingerer_count("index_finger"), 7);
        assert!(m.has_upgrade("click_mult_1"));
        assert!(m.has_achievement("first_finger"));
    }

    fn r(x: u16, y: u16, w: u16, h: u16) -> Rect {
        Rect {
            x,
            y,
            width: w,
            height: h,
        }
    }

    #[test]
    fn frac_screen_roundtrip_at_corners() {
        let biscuit = r(10, 5, 40, 20);
        // top-left corner
        let (fx, fy) = screen_to_biscuit_frac(10, 5, biscuit);
        assert!(fx <= 0.001 && fy <= 0.001);
        let (col, row) = biscuit_frac_to_screen(fx, fy, biscuit);
        assert_eq!((col, row), (10, 5));

        // bottom-right (one beyond, clamps)
        let (fx, fy) = screen_to_biscuit_frac(50, 25, biscuit);
        assert!(fx >= 0.999 && fy >= 0.999);

        // exact center
        let (col, row) = biscuit_frac_to_screen(0.5, 0.5, biscuit);
        assert_eq!(col, 30);
        assert_eq!(row, 15);
    }

    #[test]
    fn frac_position_survives_biscuit_move() {
        // A point at fraction (0.25, 0.5) of the biscuit must resolve to a
        // proportionally-shifted absolute coord when the biscuit moves /
        // grows.
        let small = r(0, 0, 40, 20);
        let (col_a, row_a) = biscuit_frac_to_screen(0.25, 0.5, small);
        let large = r(10, 5, 80, 40);
        let (col_b, row_b) = biscuit_frac_to_screen(0.25, 0.5, large);
        // Same fractional spot, very different screen coords.
        assert_ne!((col_a, row_a), (col_b, row_b));
        // And the shifted point should still sit at the 25%/50% mark of the
        // new rect.
        assert_eq!(col_b, 30); // 10 + 0.25 * 80
        assert_eq!(row_b, 25); // 5  + 0.5  * 40
    }

    #[test]
    fn zero_size_biscuit_doesnt_panic() {
        let zero = r(0, 0, 0, 0);
        let (fx, fy) = screen_to_biscuit_frac(5, 5, zero);
        assert_eq!((fx, fy), (0.5, 0.5));
        let (col, row) = biscuit_frac_to_screen(0.5, 0.5, zero);
        assert_eq!((col, row), (0, 0));
    }
}