// 入口：游戏循环 / 状态机
import { LEVELS, findLevel } from './levels/index.js';
import { Level } from './level.js';
import { Player } from './player.js';
import { Camera } from './camera.js';
import { Input } from './input.js';
import { UI } from './ui.js';
import { Save } from './save.js';
import { sfx, unlockAudio, Audio2 } from './audio.js';
import { Editor } from './editor.js';
import { clamp } from './util.js';

const W = 800, H = 608;
const STEP = 1000 / 60;

const canvas = document.getElementById('game');
const ctx = canvas.getContext('2d', { alpha: false });
ctx.imageSmoothingEnabled = false;

const G = {
  state: 'menu',      // menu | playing | paused | result | editor
  level: null, player: null, cam: null,
  data: null, idx: -1,
  deaths: 0, ms: 0, hudTick: 0,
  time: 0,
  lastLevelId: null,
};

// ---------------- 关卡流程 ----------------
function startLevel(data, idx = -1) {
  unlockAudio();
  G.data = data; G.idx = idx; G.lastLevelId = data.id;
  G.level = new Level(data);
  G.player = new Player(G.level);
  G.cam = new Camera(W, H);
  G.cam.reset(G.level, G.player);
  G.player.onDeath = () => { G.deaths++; };
  G.player.onClear = () => finish();
  G.level.bosses.forEach(b => { b.onDefeat = () => finish(); });
  G.deaths = 0; G.ms = 0; G.hudTick = 0;
  G.state = 'playing';
  UI.showGame();
  UI.toast('');
  if (data.hint) UI.toast(data.hint);
}

/** 整关从头再来：保留死亡数，丢弃所有存档点进度 */
function restart() {
  if (!G.data) return;
  const d = G.deaths;
  startLevel(G.data, G.idx);
  G.deaths = d;   // 死亡数不重置
}

/** 自杀（IWBT 的 R 键）：死后自动回到最近的存档点 */
function suicide() {
  if (!G.player || G.state !== 'playing') return;
  G.player.kill();
}

function finish() {
  if (G.state !== 'playing') return;
  G.state = 'result';
  sfx.goal();
  const apples = G.player.apples || 0;
  const total = G.level.totalApples || 0;
  const better = Save.clear(G.data.id, G.deaths, G.ms, apples);
  const hasNext = G.idx >= 0 && G.idx + 1 < LEVELS.length;
  UI.result({
    name: G.data.name, ms: G.ms, deaths: G.deaths,
    apples, totalApples: total, better, hasNext,
  });
}

function nextLevel() {
  if (G.idx >= 0 && G.idx + 1 < LEVELS.length) startLevel(LEVELS[G.idx + 1], G.idx + 1);
  else toLevels();
}
function toLevels() { G.state = 'menu'; UI.show('scr-levels'); }
function toTitle() { G.state = 'menu'; UI.show('scr-title'); }
function pause() { if (G.state === 'playing') { G.state = 'paused'; UI.show('scr-pause'); } }
function resume() { if (G.state === 'paused') { G.state = 'playing'; UI.showGame(); } }

// ---------------- 更新 ----------------
function update() {
  const L = G.level, P = G.player;
  // R = 自杀回存档点；Backspace = 整关重开
  if (Input.hit('suicide')) { suicide(); return; }
  if (Input.hit('restart')) { restart(); return; }
  if (Input.hit('pause')) { pause(); return; }

  const wasDead = P.dead;
  L.update(1, P, G.cam);
  for (const b of L.bosses) b.update(1, P);
  P.update(1);
  // 刚从死亡中复活：镜头立刻对准重生点，别慢慢飘过去
  if (wasDead && !P.dead) G.cam.snapTo(P, L);
  G.cam.update(L, P, 1);
  G.ms += STEP;
  G.time++;

  if (++G.hudTick % 5 === 0) {
    UI.hud({
      name: G.data.name, deaths: G.deaths, ms: G.ms,
      apples: P.apples, totalApples: L.totalApples, hasGun: P.hasGun,
      save: P.saveIdx || 0, totalSaves: L.totalSaves || 0,
    });
    const boss = L.bosses.find(b => !b.dead) || L.bosses[0];
    UI.bossBar(L.bosses.length ? boss : null);
  }
}

// ---------------- 渲染 ----------------
function render() {
  const t = G.time;
  if (G.state === 'playing' || G.state === 'paused' || G.state === 'result') {
    const L = G.level, P = G.player, C = G.cam;
    ctx.fillStyle = '#0a0a14';
    ctx.fillRect(0, 0, W, H);
    L.drawBg(ctx, C, t);
    ctx.save();
    C.apply(ctx);
    L.draw(ctx, C, t);
    for (const b of L.bosses) b.draw(ctx, t);
    P.draw(ctx);
    ctx.restore();
    L.drawOverlay(ctx, C, t);
    UI.toast(L.toast || '');
    // 死亡时的血色闪烁
    if (P.dead) {
      ctx.fillStyle = 'rgba(200,0,40,.18)';
      ctx.fillRect(0, 0, W, H);
    }
  } else {
    drawTitleBg(t);
  }
}

function drawTitleBg(t) {
  const g = ctx.createLinearGradient(0, 0, 0, H);
  g.addColorStop(0, '#181828'); g.addColorStop(1, '#08080f');
  ctx.fillStyle = g; ctx.fillRect(0, 0, W, H);
  // 漂浮的刺
  ctx.globalAlpha = 0.5;
  for (let i = 0; i < 26; i++) {
    const x = ((i * 137 + t * 0.15) % (W + 60)) - 30;
    const y = 120 + ((i * 71) % (H - 160));
    ctx.fillStyle = i % 3 === 0 ? '#3a3a4c' : '#2a2a38';
    ctx.beginPath();
    ctx.moveTo(x, y + 18); ctx.lineTo(x + 11, y); ctx.lineTo(x + 22, y + 18);
    ctx.closePath(); ctx.fill();
  }
  ctx.globalAlpha = 1;
  // 底部刺海
  ctx.fillStyle = '#1a1a26';
  ctx.fillRect(0, H - 30, W, 30);
  ctx.fillStyle = '#c8c8d8';
  for (let x = 0; x < W; x += 22) {
    ctx.beginPath();
    ctx.moveTo(x, H - 4); ctx.lineTo(x + 11, H - 26); ctx.lineTo(x + 22, H - 4);
    ctx.closePath(); ctx.fill();
  }
}

// ---------------- 主循环 ----------------
let last = performance.now(), acc = 0;
function loop(now) {
  requestAnimationFrame(loop);
  let dt = now - last; last = now;
  if (dt > 200) dt = 200;
  acc += dt;
  let guard = 0;
  while (acc >= STEP && guard++ < 6) {
    acc -= STEP;
    if (G.state === 'playing') update();
    else if (G.state === 'paused' && Input.hit('pause')) resume();
    Input.endFrame();
  }
  if (G.state !== 'playing') G.time++;
  render();
}

// ---------------- 启动 ----------------
Save.load();
Audio2.enabled = Save.data.audio !== false;

UI.init({
  play: (lv) => startLevel(lv, lv.builtin === false ? -1 : (lv.index ?? -1)),
  levels: toLevels,
  help: () => UI.show('scr-help'),
  editor: () => { G.state = 'editor'; UI.show('scr-editor'); Editor.open(); },
  back: toTitle,
  resume,
  restart: () => { restart(); },
  quit: toLevels,
  retry: () => startLevel(G.data, G.idx),
  next: nextLevel,
  wipe: () => {
    if (confirm('确定清除所有通关记录与自制关卡？')) { Save.wipe(); UI.renderLevels(); }
  },
});

Editor.init({
  startLevel: (data) => startLevel(data, -1),
  refresh: () => UI.renderLevels(),
});

// 首次交互解锁音频
const unlock = () => { unlockAudio(); removeEventListener('pointerdown', unlock); removeEventListener('keydown', unlock); };
addEventListener('pointerdown', unlock);
addEventListener('keydown', unlock);

UI.show('scr-title');
requestAnimationFrame(loop);

// 调试钩子
window.__IW = { G, LEVELS, Save, startLevel };