// 程序化动作帧生成器（provider 无关，本地 canvas 变换，无需 API Key）。
// 依据基础形象为每个动作生成 8-16 帧序列（PNG data URL），供 pet-engine.js 的 playClip 播放。
// 数据源必须是 data: URL 或同源资源；若为跨域远程图，canvas 会被污染导致 toDataURL 抛错，
// 此时 Promise reject，前端静默回退 CSS 动画。
(function () {
  'use strict';

  var MAX_DIM = 256;

  // 每个状态 → 一段随时间 t∈[0,1) 的仿射变换。
  // dx/dy: 相对宽/高的位移比例；rot: 弧度；sx/sy: 缩放。
  var PRESETS = {
    idle:                  { frames: 12, fps: 8,  loop: true,  tf: function (t) { var s = Math.sin(2 * Math.PI * t); return { dy: -0.015 * s, sx: 1 - 0.010 * s, sy: 1 + 0.020 * s }; } },
    happy:                 { frames: 12, fps: 14, loop: true,  tf: function (t) { return { dy: -0.060 * Math.abs(Math.sin(2 * Math.PI * t)), rot: 0.030 * Math.sin(2 * Math.PI * t) }; } },
    excited:               { frames: 14, fps: 16, loop: true,  tf: function (t) { return { dy: -0.080 * Math.abs(Math.sin(2 * Math.PI * t)), rot: 0.050 * Math.sin(2 * Math.PI * t) }; } },
    celebrate:             { frames: 16, fps: 16, loop: true,  tf: function (t) { return { dy: -0.100 * Math.abs(Math.sin(Math.PI * t)), rot: 0.080 * Math.sin(2 * Math.PI * t) }; } },
    busy:                  { frames: 8,  fps: 16, loop: true,  tf: function (t) { return { dx: 0.012 * Math.sin(4 * Math.PI * t), rot: 0.020 * Math.sin(4 * Math.PI * t) }; } },
    miniGame:              { frames: 12, fps: 14, loop: true,  tf: function (t) { return { dy: -0.060 * Math.abs(Math.sin(2 * Math.PI * t)), rot: 0.050 * Math.sin(4 * Math.PI * t) }; } },
    waitingForInteraction: { frames: 14, fps: 10, loop: true,  tf: function (t) { return { rot: 0.050 * Math.sin(2 * Math.PI * t), dx: 0.010 * Math.sin(2 * Math.PI * t) }; } },
    remind:                { frames: 10, fps: 8,  loop: true,  tf: function (t) { return { rot: 0.060 * Math.sin(4 * Math.PI * t) }; } },
    sleeping:              { frames: 16, fps: 6,  loop: true,  tf: function (t) { return { rot: 0.040, sy: 1 + 0.025 * Math.sin(2 * Math.PI * t), dy: 0.010 * Math.sin(2 * Math.PI * t) }; } },
    worried:               { frames: 12, fps: 6,  loop: true,  tf: function (t) { return { dy: 0.015, sy: 1 - 0.020 * Math.abs(Math.sin(Math.PI * t)), rot: -0.030 * Math.sin(2 * Math.PI * t) }; } },
    sad:                   { frames: 12, fps: 6,  loop: true,  tf: function (t) { return { dy: 0.015, sy: 1 - 0.020 * Math.abs(Math.sin(Math.PI * t)), rot: -0.030 * Math.sin(2 * Math.PI * t) }; } },
    tired:                 { frames: 12, fps: 5,  loop: true,  tf: function (t) { return { dy: 0.020, rot: -0.020 * Math.sin(2 * Math.PI * t) }; } },
    energetic:             { frames: 14, fps: 18, loop: true,  tf: function (t) { return { dy: -0.070 * Math.abs(Math.sin(2 * Math.PI * t)), rot: 0.040 * Math.sin(2 * Math.PI * t) }; } },
    curious:               { frames: 12, fps: 8,  loop: true,  tf: function (t) { return { rot: 0.070 * Math.sin(2 * Math.PI * t), dy: -0.020 * Math.sin(2 * Math.PI * t) }; } },
    watching:              { frames: 12, fps: 6,  loop: true,  tf: function (t) { return { rot: 0.030 * Math.sin(2 * Math.PI * t), dy: -0.010 * Math.abs(Math.sin(2 * Math.PI * t)) }; } },
    custom:                { frames: 12, fps: 8,  loop: true,  tf: function (t) { var s = Math.sin(2 * Math.PI * t); return { dy: -0.015 * s }; } }
  };

  var KNOWN_STATES = ['idle', 'happy', 'busy', 'worried', 'excited', 'sad', 'tired',
    'remind', 'energetic', 'curious', 'watching', 'waitingForInteraction', 'miniGame',
    'sleeping', 'celebrate', 'custom'];

  function presetFor(state) { return PRESETS[state] || PRESETS.idle; }

  function loadImage(src) {
    return new Promise(function (resolve, reject) {
      var img = new Image();
      img.onload = function () { resolve(img); };
      img.onerror = function () { reject(new Error('image load failed')); };
      img.src = src;
    });
  }

  function makeClip(img, preset) {
    var iw = img.naturalWidth || img.width || 120;
    var ih = img.naturalHeight || img.height || 140;
    var scale = Math.min(1, MAX_DIM / Math.max(iw, ih));
    var cw = Math.max(1, Math.round(iw * scale));
    var ch = Math.max(1, Math.round(ih * scale));
    var canvas = document.createElement('canvas');
    canvas.width = cw;
    canvas.height = ch;
    var ctx = canvas.getContext('2d');
    var frames = [];
    for (var i = 0; i < preset.frames; i++) {
      var tr = preset.tf(i / preset.frames) || {};
      ctx.clearRect(0, 0, cw, ch);
      ctx.save();
      ctx.translate(cw / 2 + (tr.dx || 0) * cw, ch / 2 + (tr.dy || 0) * ch);
      if (tr.rot) ctx.rotate(tr.rot);
      ctx.scale(tr.sx || 1, tr.sy || 1);
      ctx.drawImage(img, -cw / 2, -ch / 2, cw, ch);
      ctx.restore();
      frames.push(canvas.toDataURL('image/png'));
    }
    return {
      frames: frames,
      sprite: null,
      frame_width: cw,
      frame_height: ch,
      count: frames.length,
      fps: preset.fps,
      loop: preset.loop
    };
  }

  // 依据 config.actions（状态→动作名）为每个动作生成剪辑，按动作名为键。
  // 返回 Promise<{ [actionName]: ActionClip }>；canvas 被污染时 reject。
  function generateForConfig(config, src) {
    var actions = (config && config.actions) || {};
    var map = {}; // actionName -> state
    KNOWN_STATES.forEach(function (s) {
      var a = actions[s] || s;
      if (!(a in map)) map[a] = s;
    });
    Object.keys(actions).forEach(function (s) {
      var a = actions[s];
      if (a && !(a in map)) map[a] = s;
    });

    return loadImage(src).then(function (img) {
      var cache = {}; // state -> clip
      var out = {};
      Object.keys(map).forEach(function (actionName) {
        var state = map[actionName];
        var clip = cache[state] || (cache[state] = makeClip(img, presetFor(state)));
        out[actionName] = clip;
      });
      return out;
    });
  }

  window.cfcPetGen = { generateForConfig: generateForConfig, presets: PRESETS };
})();