// Issue 05 验收：bgm 音源 combo 与 fps 限流。
//
// A 段验音源优先级：用户自填 URL > bgm 选择（仅当本壁纸声明过）> 本壁纸默认音源；
//   且 bgm 选择跨壁纸时"音频回落、选择保留"。
// B 段验 fps：WE 不替壁纸限流，得自己门控。关键是限流只该丢帧，
//   不该改变动画相位推进速度——用同一段真实时间里 trackTime 前进了多少来判定。
import { withPage, sleep } from "../tools/cdp.mjs";

const BASE = "http://127.0.0.1:8190/";
const name = (src) => (src ? decodeURIComponent(String(src).split("/").pop()) : "(空)");

let failures = 0;
const check = (ok, msg, detail) => {
  if (!ok) failures++;
  console.log(`  ${ok ? "✓" : "✗"} ${msg}${detail !== undefined ? `  → ${detail}` : ""}`);
};

// ───────────────────────── A 段：音源 ─────────────────────────
console.log("=== A 段：bgm 音源选择与回落 ===");
await withPage({ width: 1280, height: 720 }, async ({ send, evaluate, exceptions }) => {
  await send("Page.navigate", { url: BASE + "?__freeze=1" });
  const deadline = Date.now() + 30000;
  while (Date.now() < deadline) {
    if (await evaluate('!!(window.__test && (window.__test.successAt || window.__test.error))')) break;
    await sleep(150);
  }
  await sleep(600);

  const src = () => evaluate('document.getElementById("background-music").src');
  const preset = (v) => evaluate(`window.wallpaperPropertyListener.applyUserProperties({ preset: { value: ${JSON.stringify(v)} } })`);
  const bgm = (v) => evaluate(`window.wallpaperPropertyListener.applyUserProperties({ bgm: { value: ${JSON.stringify(v)} } })`);
  const file = (v) => evaluate(`window.wallpaperPropertyListener.applyUserProperties({ audio_file: { value: ${JSON.stringify(v)} } })`);

  const seen = [];
  const step = async (label, action, expected) => {
    await action();
    await sleep(350);
    const got = name(await src());
    seen.push(`${label}=${got}`);
    check(got === expected, label, `期望 ${expected}，实得 ${got}`);
  };

  // 载入即 xilian，默认音源应是「再度和你」
  check(name(await src()) === "「再度和你」.flac", "初始默认音源 = 昔涟立绘默认", name(await src()));

  // 无损是否真的可用，取决于 CEF 能不能解 FLAC——不能只看路径对不对。
  // readyState>=1(HAVE_METADATA) 说明容器与编码被接受，duration>0 说明解析出了正确时长。
  const healthProbe = `(function(){
    var a = document.getElementById("background-music");
    return { rs: a.readyState, dur: a.duration, net: a.networkState,
             err: a.error ? a.error.code : null, flac: a.canPlayType("audio/flac") };
  })()`;
  let h = null;
  for (let i = 0; i < 40; i++) {
    h = await evaluate(healthProbe);
    if (h.rs >= 1 || h.err !== null) break;
    await sleep(250);
  }
  check(h.flac === "probably" || h.flac === "maybe", "CEF 支持 audio/flac", h.flac || "(不支持)");
  check(h.err === null, "音频无解码错误", h.err === null ? "无" : `MediaError.code=${h.err}`);
  check(h.rs >= 1, "FLAC 已解析出元数据（readyState≥1）", `readyState=${h.rs}`);
  check(h.dur > 100 && h.dur < 300, "解析出的时长符合源文件", `${h.dur?.toFixed(1)} 秒`);

  // 元数据能解析 ≠ 真的在放。等一会儿看播放头有没有前进——这才是"无损可用"的终局证据。
  await sleep(1500);
  const pb = await evaluate(`(function(){
    var a = document.getElementById("background-music");
    return { paused: a.paused, t: a.currentTime, loop: a.loop, vol: a.volume };
  })()`);
  check(!pb.paused, "音频处于播放状态", pb.paused ? "仍暂停" : "播放中");
  check(pb.t > 0.5, "播放头已前进（确实在解码播放）", `currentTime=${Number(pb.t).toFixed(2)} s`);
  check(pb.loop === true, "循环播放已开启", String(pb.loop));

  await step("bgm 选「昔涟」", () => bgm("xilian"), "昔涟.flac");
  await step("切到 kv37（选择不属于它）→ 回落", () => preset("kv37"), "pv37.mp3");
  await step("bgm 选「版本 PV」（属于 kv37）", () => bgm("pv37"), "pv37.mp3");
  await step("切回 xilian（pv37 不属于它）→ 回落", () => preset("xilian"), "「再度和你」.flac");
  await step("bgm 选「「再度和你」」", () => bgm("zaiduheni"), "「再度和你」.flac");
  await step("bgm 回到「随预设」", () => bgm("auto"), "「再度和你」.flac");

  // 用户自填 URL 优先级最高
  await step("bgm 选「昔涟」后填自定义 URL", async () => {
    await bgm("xilian");
    await file("https://example.com/custom-track.mp3");
  }, "custom-track.mp3");
  await step("切壁纸不得清掉自定义 URL", () => preset("kv37"), "custom-track.mp3");
  await step("清空自定义 URL → 回到预设默认", () => file(""), "pv37.mp3");

  console.log(`  音源轨迹: ${seen.join("  |  ")}`);
  console.log(`  未捕获异常: ${exceptions.length ? exceptions.join(" | ") : "无 ✓"}`);
  if (exceptions.length) failures++;
});

// ───────────────────────── B 段：fps ─────────────────────────
console.log("\n=== B 段：fps 限流 ===");
await withPage({ width: 1280, height: 720 }, async ({ send, evaluate, exceptions }) => {
  // 空 __props 只用来触发测试驱动注入（不带它就不会注入），既不冻结也不改属性
  await send("Page.navigate", { url: BASE + "?__props=%7B%7D" });
  const deadline = Date.now() + 30000;
  while (Date.now() < deadline) {
    if (await evaluate('!!(window.__test && (window.__test.successAt || window.__test.error))')) break;
    await sleep(150);
  }
  await sleep(1200); // 让动画先跑起来，避开启动瞬态

  const probe = `(function(){
    var p = window.__player;
    var e = p.animationState.getCurrent(0);
    return { trackTime: e.trackTime, duration: e.animation.duration,
             draws: window.__test.drawCalls, t: performance.now() };
  })()`;

  const sample = async (seconds) => {
    const a = await evaluate(probe);
    await sleep(seconds * 1000);
    const b = await evaluate(probe);
    const wall = (b.t - a.t) / 1000;
    let phase = b.trackTime - a.trackTime;
    if (phase < 0) phase += b.duration; // 动画正好绕回
    return { wall, draws: b.draws - a.draws, fps: (b.draws - a.draws) / wall, phaseRate: phase / wall };
  };

  const setFps = async (v) => {
    await evaluate(`window.wallpaperPropertyListener.applyGeneralProperties({ fps: ${v} })`);
    await sleep(400);
  };

  const results = [];
  const run = async (label, target) => {
    const r = await sample(2.0);
    const row = { label, target, ...r };
    results.push(row);
    console.log(
      `  ${label.padEnd(16)} 实测 ${r.fps.toFixed(1)} fps` +
        (target ? `（目标 ${target}）` : "（不限流）") +
        `   动画相位推进 ${r.phaseRate.toFixed(3)} 倍速`,
    );
    return row;
  };

  const base = await run("不限流", 0);
  await setFps(30);
  const f30 = await run("限 30 fps", 30);
  await setFps(20);
  const f20 = await run("限 20 fps", 20);
  await setFps(0);
  const back = await run("恢复不限流", 0);

  check(Math.abs(f30.fps - 30) / 30 < 0.25, "限 30 fps 生效", `实测 ${f30.fps.toFixed(1)}`);
  check(Math.abs(f20.fps - 20) / 20 < 0.25, "限 20 fps 生效", `实测 ${f20.fps.toFixed(1)}`);
  check(f30.fps < base.fps * 0.75, "限流确实减少了绘制次数", `${base.fps.toFixed(1)} → ${f30.fps.toFixed(1)}`);
  check(back.fps > f30.fps * 1.5, "取消限流后帧率恢复", `${f30.fps.toFixed(1)} → ${back.fps.toFixed(1)}`);
  for (const r of [f30, f20, back]) {
    check(
      Math.abs(r.phaseRate - base.phaseRate) / base.phaseRate < 0.1,
      `动画相位推进速度未受 ${r.label} 影响`,
      `${r.phaseRate.toFixed(3)} vs 基准 ${base.phaseRate.toFixed(3)}`,
    );
  }
  console.log(`  未捕获异常: ${exceptions.length ? exceptions.join(" | ") : "无 ✓"}`);
  if (exceptions.length) failures++;
});

console.log(`\n结论：${failures === 0 ? "全部通过 ✓" : `${failures} 项失败 ✗`}`);
process.exit(failures === 0 ? 0 : 1);