import 'pixi.js/unsafe-eval'; // Pixi without eval, required by our Content-Security-Policy
import { Application, CanvasSource, Container, ImageSource, Sprite, Texture } from 'pixi.js';
import { Anim, CHARACTER_IDS } from '../shared/characters';
import { DEFAULT_CHARACTER_ID, INTERPOLATION_DELAY_MS, PROTOCOL_VERSION } from '../shared/constants';
import { buildTerrain, parseMapDefinition } from '../shared/maps/loader';
import { parseHexColor, parseMaterials, type MaterialRegistry } from '../shared/materials';
import { hello, type ChunkInfo, type ChunkState, type PlayerInfo, type PlayerState, type ServerMessage } from '../shared/protocol';
import type { TerrainBitmap } from '../shared/terrain/bitmap';
import { applyTerrainEvent, type SequencedEvent, type TerrainEvent } from '../shared/terrain/events';
import { rleDecode } from '../shared/terrain/rle';
import {
  CAMERA_AIM_LEAD,
  CAMERA_FOLLOW_SPEED,
  CAMERA_VIEW_HEIGHT,
  CRUSH_SHAKE,
  FREEZE_FRAME_MS,
  HIT_SHAKE,
  INPUT_SEND_HZ,
  LANDING_DUST_MIN_VY,
  MERGE_SHAKE,
  PARTICLES_PER_100_PX,
  PLAYER_SPLAT_COLOR,
  POPUP_COOLDOWN,
  POPUP_MIN_PIXELS,
  SHAKE_DECAY,
  SHAKE_MAX,
  SHAKE_PER_PIXEL,
} from './config';
import { ChunkView } from './entities/ChunkView';
import { PlayerView } from './entities/PlayerView';
import { Particles } from './fx/Particles';
import { Popups } from './fx/Popups';
import { fr } from './i18n/fr';
import { InputTracker } from './input';
import { Connection } from './net/connection';
import { SnapshotBuffer } from './net/interpolation';
import { TerrainView } from './terrain/TerrainView';
import { showBrowser } from './ui/browser';
import { LobbyPanel } from './ui/lobbyPanel';
import { showMenu, type MenuChoice } from './ui/menu';

const PORTRAIT_RADIUS = 34;
const EATING_POPUP_RANGE = 120;

const statusEl = document.getElementById('status')!;
const fpsEl = document.getElementById('fps')!;
const helpEl = document.getElementById('help')!;
const setStatus = (text: string): void => {
  statusEl.textContent = text;
};

/** Everything tied to one loaded map. Rebuilt when a match starts. */
interface World {
  materials: MaterialRegistry;
  terrain: TerrainBitmap;
  view: TerrainView;
  background: Sprite;
  lastSeq: number;
}

async function loadWorld(mapId: string, materials: MaterialRegistry): Promise<World> {
  const files = await window.assets.map(mapId);
  const def = parseMapDefinition(files.definition, mapId);
  const terrain = buildTerrain(def, files.terrain, materials);
  const bitmap = await createImageBitmap(new Blob([files.background as BlobPart], { type: 'image/png' }));
  const background = new Sprite(new Texture({ source: new ImageSource({ resource: bitmap }) }));
  return { materials, terrain, view: new TerrainView(terrain, materials), background, lastSeq: 0 };
}

/** Screen-space warm vignette drawn over the game. */
function makeVignette(): Sprite {
  const canvas = document.createElement('canvas');
  canvas.width = 512;
  canvas.height = 512;
  const ctx = canvas.getContext('2d')!;
  const grad = ctx.createRadialGradient(256, 230, 140, 256, 256, 380);
  grad.addColorStop(0, 'rgba(255, 220, 160, 0)');
  grad.addColorStop(0.7, 'rgba(120, 60, 20, 0.12)');
  grad.addColorStop(1, 'rgba(59, 36, 20, 0.45)');
  ctx.fillStyle = grad;
  ctx.fillRect(0, 0, 512, 512);
  return new Sprite(new Texture({ source: new CanvasSource({ resource: canvas }) }));
}

/** Renders each character's idle pose to a canvas for the menu. */
function makePortraits(app: Application): Map<string, HTMLCanvasElement> {
  const out = new Map<string, HTMLCanvasElement>();
  CHARACTER_IDS.forEach((characterId, i) => {
    const view = new PlayerView({ id: i + 1, name: '', characterId, radius: PORTRAIT_RADIUS });
    view.drawIdle();
    out.set(characterId, app.renderer.extract.canvas({ target: view.container, resolution: 2 }) as HTMLCanvasElement);
    view.destroy();
  });
  return out;
}

/** Title menu then game browser, until the player picks a game to host or join. */
async function chooseGame(app: Application): Promise<{ choice: MenuChoice; address: string; port: number }> {
  const portraits = makePortraits(app);
  for (;;) {
    const choice = await showMenu(CHARACTER_IDS, DEFAULT_CHARACTER_ID, portraits);
    const target = await showBrowser();
    if (target.mode === 'back') continue;
    if (target.mode === 'join') return { choice, address: target.address, port: target.port };
    setStatus(fr.connecting);
    const { port } = await window.lan.host(fr.browser.gameName(choice.name));
    return { choice, address: '127.0.0.1', port };
  }
}

async function start(): Promise<void> {
  const app = new Application();
  const host = document.getElementById('game')!;
  await app.init({ resizeTo: window, background: 0xfff1d6, antialias: true });
  host.appendChild(app.canvas);

  const { choice, address, port } = await chooseGame(app);
  helpEl.textContent = fr.help[choice.characterId] ?? '';
  setStatus(fr.connecting);

  const camera = new Container();
  const worldRoot = new Container();
  camera.addChild(worldRoot);
  const vignette = makeVignette();
  app.stage.addChild(camera, vignette);
  const particles = new Particles();
  const popups = new Popups();
  const playersLayer = new Container();
  const chunksLayer = new Container();
  // Map-independent layers always sit above the map ones (background, terrain).
  worldRoot.addChild(chunksLayer, playersLayer, particles.graphics, popups.container);

  const materials = parseMaterials(await window.assets.materials());

  let world: World | null = null;
  /** Bumped on every map (re)load, so a slow load never installs a stale world. */
  let generation = 0;
  let localId = -1;
  let pendingEvents: SequencedEvent[] = [];
  /** Server hash waiting for this client to reach the same event seq. */
  let pendingHash: { seq: number; hash: number } | null = null;
  let infos = new Map<number, PlayerInfo>();
  const views = new Map<number, PlayerView>();
  const chunkViews = new Map<number, ChunkView>();
  let snapshots = new SnapshotBuffer();
  const input = new InputTracker(app.canvas);
  let states = new Map<number, PlayerState>();
  let shake = 0;
  let freezeUntil = 0;
  let popupCooldown = 0;

  const nearEater = (x: number, y: number): boolean => {
    for (const s of states.values()) {
      if (s.anim & Anim.Special && Math.hypot(s.x - x, s.y - y) < EATING_POPUP_RANGE) return true;
    }
    return false;
  };

  const addChunk = (id: number, mask: Uint8Array, w: number, h: number, state: ChunkState): void => {
    if (!world || chunkViews.has(id)) return;
    const view = new ChunkView(world.view.makeChunkTexture(mask, w, h, Math.round(state.x), Math.round(state.y)), state);
    chunkViews.set(id, view);
    chunksLayer.addChild(view.sprite);
  };

  const removeChunk = (id: number): void => {
    chunkViews.get(id)?.destroy();
    chunkViews.delete(id);
  };

  /** Most common material of a mask, for debris colors. */
  const mainColor = (cells: Uint8Array): number => {
    const counts = new Map<number, number>();
    for (const v of cells) if (v !== 0) counts.set(v, (counts.get(v) ?? 0) + 1);
    let best = 1;
    let bestN = -1;
    for (const [v, n] of counts) if (n > bestN) [best, bestN] = [v, n];
    const m = world?.materials.byId[best];
    return m ? parseHexColor(m.color) : 0xffffff;
  };

  /** Compares our bitmap with the server's once we have applied the same events (readme §9, M3). */
  const checkHash = (): void => {
    if (!world || !pendingHash || world.lastSeq !== pendingHash.seq) return;
    const mine = world.terrain.hash();
    if (mine !== pendingHash.hash) {
      console.error(`[net] DESYNC at seq ${pendingHash.seq}: server ${pendingHash.hash}, client ${mine}`);
      setStatus(fr.desync);
      conn.send({ t: 'desync', seq: pendingHash.seq, hash: mine });
    }
    pendingHash = null;
  };

  /**
   * Applies one terrain event in sequence. `live` is false while replaying history:
   * no effects, and no chunk sprites (chunks still falling come from the welcome message).
   */
  const applyServerEvent = (seq: number, ev: TerrainEvent, live: boolean): void => {
    if (!world) {
      pendingEvents.push({ seq, ev });
      return;
    }
    if (seq !== world.lastSeq + 1) console.error(`[net] terrain event out of order: got ${seq}, expected ${world.lastSeq + 1}`);
    world.lastSeq = seq;
    const { removedByMaterial } = applyTerrainEvent(world.terrain, ev, world.materials);
    world.view.onEvent(ev);
    checkHash();

    if (ev.kind === 'op') {
      if (!live) return;
      const { op } = ev;
      let total = 0;
      for (const [mat, count] of removedByMaterial) {
        total += count;
        const m = world.materials.byId[mat];
        if (m) particles.burst(op.x, op.y, Math.ceil((count / 100) * PARTICLES_PER_100_PX), parseHexColor(m.color));
      }
      shake = Math.min(SHAKE_MAX, shake + total * SHAKE_PER_PIXEL);
      if (total >= POPUP_MIN_PIXELS && popupCooldown <= 0) {
        popupCooldown = POPUP_COOLDOWN;
        popups.spawn(op.x, op.y - op.r, nearEater(op.x, op.y) ? fr.onomatopoeia.munch : fr.onomatopoeia.crunch);
      }
      return;
    }

    const cells = rleDecode(ev.kind === 'detach' ? ev.mask : ev.patch, ev.w * ev.h);
    if (ev.kind === 'detach') {
      if (!live) return;
      if (ev.debris) particles.burst(ev.x + ev.w / 2, ev.y + ev.h / 2, Math.max(3, Math.ceil(cells.length / 20)), mainColor(cells), 200);
      else addChunk(ev.id, cells, ev.w, ev.h, { id: ev.id, x: ev.x, y: ev.y, angle: 0 });
      return;
    }
    // Merge: the sprite becomes terrain again.
    removeChunk(ev.id);
    if (!live) return;
    particles.puff(ev.x + ev.w / 2, ev.y + ev.h, 12);
    shake = Math.min(SHAKE_MAX, shake + MERGE_SHAKE);
    popups.spawn(ev.x + ev.w / 2, ev.y, fr.onomatopoeia.thud, 30);
  };

  /** Drops the current map and everything on it, then loads `mapId` and replays `history`. */
  const resetWorld = (mapId: string, history: SequencedEvent[], chunks: ChunkInfo[]): void => {
    const gen = ++generation;
    if (world) {
      world.background.destroy({ texture: true, textureSource: true });
      world.view.container.destroy({ children: true, texture: true, textureSource: true });
    }
    world = null;
    pendingEvents = [];
    pendingHash = null;
    for (const id of [...chunkViews.keys()]) removeChunk(id);
    for (const view of views.values()) view.destroy();
    views.clear();
    snapshots = new SnapshotBuffer();
    setStatus(fr.loadingMap);
    void loadWorld(mapId, materials)
      .then((w) => {
        if (gen !== generation) return; // superseded by a newer start
        world = w;
        worldRoot.addChildAt(w.background, 0);
        worldRoot.addChildAt(w.view.container, 1);
        for (const { seq, ev } of history) applyServerEvent(seq, ev, false);
        for (const c of chunks) addChunk(c.id, rleDecode(c.mask, c.w * c.h), c.w, c.h, c.state);
        const live = pendingEvents;
        pendingEvents = [];
        for (const { seq, ev } of live) applyServerEvent(seq, ev, true);
        setStatus('');
      })
      .catch((err: unknown) => setStatus(fr.loadError(err instanceof Error ? err.message : String(err))));
  };

  const lobbyPanel = new LobbyPanel(
    () => localId,
    (ready) => conn.send({ t: 'ready', ready }),
  );

  const onMessage = (msg: ServerMessage): void => {
    switch (msg.t) {
      case 'welcome':
        localId = msg.playerId;
        infos = new Map(msg.players.map((p) => [p.id, p]));
        resetWorld(msg.mapId, msg.events, msg.chunks);
        break;
      case 'start':
        infos = new Map(msg.players.map((p) => [p.id, p]));
        resetWorld(msg.mapId, [], []);
        setStatus(fr.lobby.started);
        setTimeout(() => {
          if (statusEl.textContent === fr.lobby.started) setStatus('');
        }, 1500);
        break;
      case 'lobby':
        lobbyPanel.update(msg.phase, msg.players, msg.countdown);
        break;
      case 'reject':
        setStatus(
          msg.reason === 'version'
            ? fr.rejectedVersion(msg.serverVersion, PROTOCOL_VERSION)
            : msg.reason === 'character'
              ? fr.rejectedCharacter
              : fr.rejectedFull,
        );
        break;
      case 'playerJoined':
        infos.set(msg.player.id, msg.player);
        break;
      case 'playerLeft':
        infos.delete(msg.id);
        views.get(msg.id)?.destroy();
        views.delete(msg.id);
        break;
      case 'terrain':
        applyServerEvent(msg.seq, msg.ev, true);
        break;
      case 'hash':
        pendingHash = { seq: msg.seq, hash: msg.hash };
        checkHash();
        break;
      case 'chunkRemoved':
        removeChunk(msg.id);
        break;
      case 'crushed':
        popups.spawn(msg.x, msg.y, fr.onomatopoeia.crush, 46);
        particles.burst(msg.x, msg.y, 24, PLAYER_SPLAT_COLOR, 500);
        shake = Math.min(SHAKE_MAX, shake + CRUSH_SHAKE);
        freezeUntil = performance.now() + FREEZE_FRAME_MS * 2;
        break;
      case 'snapshot':
        snapshots.push(performance.now(), msg.players, msg.chunks);
        break;
    }
  };

  const conn = new Connection(
    `ws://${address}:${port}`,
    onMessage,
    () => conn.send(hello(choice.name, choice.characterId)),
    () => {
      setStatus(fr.disconnected);
      lobbyPanel.update('playing', [], null); // hide it
    },
  );

  const screenToWorld = (sx: number, sy: number): [number, number] => [
    (sx - camera.x) / camera.scale.x - worldRoot.x,
    (sy - camera.y) / camera.scale.y - worldRoot.y,
  ];

  setInterval(() => {
    const [aimX, aimY] = screenToWorld(input.mouseX, input.mouseY);
    conn.send({ t: 'input', buttons: input.buttons, aimX: Math.round(aimX), aimY: Math.round(aimY) });
  }, 1000 / INPUT_SEND_HZ);

  let camX = 0;
  let camY = 0;
  let cameraReady = false;
  let fpsAcc = 0;
  let fpsFrames = 0;
  app.ticker.add((ticker) => {
    const dt = Math.min(0.05, ticker.deltaMS / 1000);
    fpsAcc += ticker.deltaMS / 1000;
    fpsFrames++;
    if (fpsAcc >= 0.5) {
      fpsEl.textContent = fr.fps(Math.round(fpsFrames / fpsAcc));
      fpsAcc = 0;
      fpsFrames = 0;
    }
    vignette.width = app.screen.width;
    vignette.height = app.screen.height;
    if (!world) return;
    // Freeze-frame: hold the last image for a beat on big hits.
    if (performance.now() < freezeUntil) return;

    world.view.update();
    particles.update(dt);
    popups.update(dt);
    popupCooldown -= dt;

    const sample = snapshots.sample(performance.now() - INTERPOLATION_DELAY_MS);
    states = sample.players;
    for (const [id, view] of chunkViews) {
      const s = sample.chunks.get(id);
      if (s) view.update(s);
    }
    const [aimX, aimY] = screenToWorld(input.mouseX, input.mouseY);
    for (const [id, state] of states) {
      const info = infos.get(id);
      if (!info) continue;
      let view = views.get(id);
      if (!view) {
        view = new PlayerView(info);
        views.set(id, view);
        playersLayer.addChild(view.container);
      }
      const ev = view.update(state, id === localId ? aimX : state.x + state.facing * 100, id === localId ? aimY : state.y, dt);
      if (ev.landed && ev.landingSpeed > LANDING_DUST_MIN_VY) particles.puff(state.x, state.y + state.size, 8);
      if (ev.stunnedNow) {
        popups.spawn(state.x, state.y - state.size, fr.onomatopoeia.hit, 40);
        particles.burst(state.x, state.y, 10, 0xffe14d, 300);
        shake = Math.min(SHAKE_MAX, shake + HIT_SHAKE);
        freezeUntil = performance.now() + FREEZE_FRAME_MS;
      }
    }

    // Camera: follow the local player with a lead toward the cursor, clamped to the map, with screen shake.
    const scale = app.screen.height / CAMERA_VIEW_HEIGHT;
    camera.scale.set(scale);
    const me = states.get(localId);
    const viewW = app.screen.width / scale;
    const viewH = app.screen.height / scale;
    if (me) {
      const tx = me.x + (aimX - me.x) * CAMERA_AIM_LEAD - viewW / 2;
      const ty = me.y + (aimY - me.y) * CAMERA_AIM_LEAD - viewH / 2;
      const k = cameraReady ? Math.min(1, CAMERA_FOLLOW_SPEED * dt) : 1;
      cameraReady = true;
      camX += (tx - camX) * k;
      camY += (ty - camY) * k;
    }
    const { width, height } = world.terrain;
    const cx = viewW >= width ? (width - viewW) / 2 : Math.max(0, Math.min(width - viewW, camX));
    const cy = viewH >= height ? (height - viewH) / 2 : Math.max(0, Math.min(height - viewH, camY));
    shake = Math.max(0, shake - SHAKE_DECAY * dt);
    worldRoot.position.set(Math.round(-cx + (Math.random() - 0.5) * shake * 2), Math.round(-cy + (Math.random() - 0.5) * shake * 2));
  });
}

start().catch((err: unknown) => {
  console.error(err);
  setStatus(fr.loadError(err instanceof Error ? err.message : String(err)));
});