/**
 * 工作进程池的调度不变量。
 *
 * 这些用例**真的 fork 子进程**，用一个极小的桩 worker（不装 pi SDK）：
 * 要验的是调度（并发上限、同会话串行、排队、硬超时、状态跨 worker 存活），
 * 而不是模型怎么跑。用桩让每个用例在几百毫秒内完成。
 *
 * 桩 worker 的协议与真 worker 一致：`ready` → 收 `job` → 按 `__hold` 停一会儿
 * → 发 `done`。它还把收到的 job 载荷原样回声成一行 `JOB {…}` 日志 ——
 * 判据因此能落在「主进程真的把 sessionFile / grants / 命名指纹传下来了」上，
 * 而不是一个间接的计数（计数在字段被丢掉时依然会给出绿色）。
 */

import { test } from 'node:test';
import assert from 'node:assert/strict';
import { mkdtempSync, writeFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';

// ─── 桩 worker ───
//
// 落到临时目录而不是仓库里：它是测试脚手架，不该被 check-shared-libs 之类的
// 一致性脚本看到，也不该让人误以为是第二个真 worker。
const STUB_DIR = mkdtempSync(join(tmpdir(), 'pi-pool-test-'));
const STUB = join(STUB_DIR, 'stub-worker.mjs');
writeFileSync(STUB, `
process.on('message', (msg) => {
  if (msg?.type === 'job') {
    const hold = msg.data?.__hold ?? 30;
    process.send({ type: 'log', line: 'JOB ' + JSON.stringify({
      mailID: msg.data.mail_id,
      kind: msg.kind,
      sessionFile: msg.session?.sessionFile || '',
      cwd: msg.session?.cwd || '',
      grants: msg.grants || [],
      lastSyncedName: msg.lastSyncedName || '',
      turnTimeoutMs: msg.config?.turnTimeoutMs ?? null,
    }) });
    process.send({ type: 'session_opened', piSessionId: 'pi-' + msg.data.mail_id,
                   sessionFile: '/tmp/f-' + msg.data.mail_id + '.jsonl', cwd: '/tmp', reused: false });
    if (msg.data?.__grant) {
      process.send({ type: 'permission_grant', toolName: msg.data.__grant });
    }
    if (msg.data?.__name) {
      process.send({ type: 'name_synced', signature: msg.data.__name });
    }
    if (msg.data?.__reopen) {
      // 模型降级换会话：同一个 worker 里第二次 session_opened
      process.send({ type: 'session_opened', piSessionId: msg.data.__reopen,
                     sessionFile: '/tmp/f2.jsonl', cwd: '/tmp', reused: false });
    }
    if (msg.data?.__pending) {
      process.send({ type: 'permission_pending', relayKey: msg.data.__pending });
      return;                                   // 等决策，见下面的分支
    }
    // 每 40ms 报一次心跳：并发的判据必须是「两个进程真的同时在干活」，
    // 而不是「running map 里有两个条目」—— fork 返回后立即就有两个条目了。
    const beat = setInterval(() => process.send({ type: 'log', line: 'TICK ' + msg.data.mail_id }), 40);
    if (hold < 0) return;                       // 永不结束，用来验硬超时
    setTimeout(() => {
      clearInterval(beat);
      process.send({ type: 'done', ok: true, error: '' });
      setTimeout(() => process.exit(0), 20);
    }, hold);
    return;
  }
  if (msg?.type === 'permission_decision') {
    process.send({ type: 'log', line: 'DECISION ' + msg.relayKey + '=' + msg.decision });
    process.send({ type: 'done', ok: true, error: '' });
    setTimeout(() => process.exit(0), 20);
    return;
  }
  if (msg?.type === 'shutdown') {
    process.send({ type: 'log', line: 'SHUTDOWN' });
    setTimeout(() => process.exit(0), 10);
  }
});
process.send({ type: 'ready' });
`);

const { createWorkerPool } = await import('../src/pool.mjs');

/** 建一个用桩 worker 的池。 */
function makePool(opts = {}) {
  const lines = [];
  const pool = createWorkerPool({
    log: (...a) => lines.push(a.join(' ')),
    config: () => ({ turnTimeoutMs: 1000, ...(opts.config || {}) }),
    onReconfigure: opts.onReconfigure || (() => {}),
    maxWorkers: opts.maxWorkers ?? 2,
    workerMaxMs: opts.workerMaxMs ?? 5000,
    workerPath: opts.workerPath || STUB,
  });
  return { pool, lines };
}

const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

/** 轮询到条件成立或超时 —— 比固定 sleep 稳。 */
async function until(fn, timeoutMs = 4000) {
  const t0 = Date.now();
  while (Date.now() - t0 < timeoutMs) {
    if (fn()) return true;
    await sleep(20);
  }
  return false;
}

/** 从日志行里取出桩 worker 回声的 job 载荷。 */
function jobs(lines) {
  const out = [];
  for (const l of lines) {
    const i = l.indexOf('JOB ');
    if (i === -1) continue;
    try { out.push(JSON.parse(l.slice(i + 4))); } catch { /* 不是完整一行 */ }
  }
  return out;
}

/** 某个 mailID 的心跳出现过几次。 */
const ticks = (lines, id) => lines.filter((l) => l.includes(`TICK ${id}`)).length;

test('并发上限被遵守：第三条会话要等前面空出来', async () => {
  const { pool } = makePool({ maxWorkers: 2 });
  for (const id of ['a', 'b', 'c']) {
    pool.submit('mail', { mail_id: id, session_id: `S-${id}`, __hold: 250 });
  }

  let peak = 0;
  const t = setInterval(() => { peak = Math.max(peak, pool.stats().running); }, 15);
  const sawQueue = await until(() => pool.stats().queued > 0, 1000);
  await until(() => pool.stats().running === 0 && pool.stats().queued === 0);
  clearInterval(t);
  pool.stop();

  assert.ok(peak <= 2, `同时跑的 worker 峰值 ${peak}，不该超过 maxWorkers=2`);
  assert.ok(sawQueue, '满载时第三封该进队列而不是被丢掉');
});

test('同一会话串行：两个 worker 的心跳不得重叠', async () => {
  const { pool, lines } = makePool({ maxWorkers: 3 });
  pool.submit('mail', { mail_id: 'm1', session_id: 'SAME', __hold: 220 });
  pool.submit('mail', { mail_id: 'm2', session_id: 'SAME', __hold: 60 });

  // 判据一：任一时刻只有一个 worker 在跑。
  let everTwo = false;
  const t = setInterval(() => { if (pool.stats().running > 1) everTwo = true; }, 10);
  await until(() => jobs(lines).length === 2 && pool.stats().running === 0, 5000);
  clearInterval(t);
  pool.stop();

  assert.equal(everTwo, false, '同一条会话不得有两个 worker 同时装载会话文件');
  // 判据二：m2 一次心跳都没能在 m1 结束前发出 —— m1 的心跳数应当远多于 m2。
  assert.ok(ticks(lines, 'm1') >= 3, `m1 该跑满 220ms，实际心跳 ${ticks(lines, 'm1')} 次`);
  assert.equal(jobs(lines).length, 2, '两封都要被处理，不能因为串行而丢掉一封');
});

test('不同会话真并发：两个进程的心跳在同一段时间里交错', async () => {
  const { pool, lines } = makePool({ maxWorkers: 3 });
  pool.submit('mail', { mail_id: 'p', session_id: 'S-P', __hold: 300 });
  pool.submit('mail', { mail_id: 'q', session_id: 'S-Q', __hold: 300 });

  const interleaved = await until(() => ticks(lines, 'p') >= 2 && ticks(lines, 'q') >= 2, 2500);
  pool.stop();
  assert.ok(interleaved,
    `两条不同会话应当并发，实际 p=${ticks(lines, 'p')} q=${ticks(lines, 'q')} 次心跳`);
});

test('sessionFile 与 cwd 跨 worker 传下去：第二封接着第一封的会话谈', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2 });
  pool.submit('mail', { mail_id: 'first', session_id: 'KEEP', __hold: 30 });
  await until(() => jobs(lines).length === 1 && pool.stats().running === 0);

  pool.submit('mail', { mail_id: 'second', session_id: 'KEEP', __hold: 30 });
  await until(() => jobs(lines).length === 2 && pool.stats().running === 0);
  pool.stop();

  const [j1, j2] = jobs(lines);
  assert.equal(j1.sessionFile, '', '第一封时还没有会话文件');
  assert.equal(j2.sessionFile, '/tmp/f-first.jsonl',
    '第二封必须带上第一封开出来的会话文件，否则每封邮件都从零开始、上下文全丢');
  assert.equal(j2.cwd, '/tmp', 'cwd 也要传下去');
});

test('「一直同意」与命名指纹跨 worker 存活', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2 });
  pool.submit('mail', {
    mail_id: 'g1', session_id: 'GRANT', __hold: 30,
    __grant: 'bash', __name: 'platform:某名字|某名字',
  });
  await until(() => jobs(lines).length === 1 && pool.stats().running === 0);

  pool.submit('mail', { mail_id: 'g2', session_id: 'GRANT', __hold: 30 });
  await until(() => jobs(lines).length === 2 && pool.stats().running === 0);
  pool.stop();

  const [j1, j2] = jobs(lines);
  assert.deepEqual(j1.grants, [], '第一封时还没人点过「一直同意」');
  assert.deepEqual(j2.grants, ['bash'],
    '「一直同意」不跨 worker 存活的话，下一封邮件又问一遍 —— 那个选项就是在骗人');
  assert.equal(j2.lastSyncedName, 'platform:某名字|某名字',
    '命名指纹要传下去，否则每封邮件都重新 sync 一次');
});

test('config() 每次派活时重取：allowedModels 随心跳变，不能用快照', async () => {
  let turnTimeoutMs = 111;
  const { pool, lines } = makePool({ maxWorkers: 1, config: {} });
  // makePool 的 config 是固定值，这里换成动态的
  pool.stop();

  const lines2 = [];
  const p2 = createWorkerPool({
    log: (...a) => lines2.push(a.join(' ')),
    config: () => ({ turnTimeoutMs }),
    onReconfigure: () => {},
    maxWorkers: 1,
    workerMaxMs: 5000,
    workerPath: STUB,
  });
  p2.submit('mail', { mail_id: 'c1', session_id: 'C1', __hold: 20 });
  await until(() => jobs(lines2).length === 1 && p2.stats().running === 0);
  turnTimeoutMs = 222;
  p2.submit('mail', { mail_id: 'c2', session_id: 'C2', __hold: 20 });
  await until(() => jobs(lines2).length === 2 && p2.stats().running === 0);
  p2.stop();

  const [j1, j2] = jobs(lines2);
  assert.equal(j1.turnTimeoutMs, 111);
  assert.equal(j2.turnTimeoutMs, 222, 'config() 必须每次重取，否则 worker 用的是上一轮的模型范围');
  assert.equal(lines.length >= 0, true);
});

test('硬超时回收卡死的 worker，且不堵住同会话后续邮件', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2, workerMaxMs: 400 });
  pool.submit('mail', { mail_id: 'stuck', session_id: 'STUCK', __hold: -1 });
  await until(() => pool.stats().running === 1, 1500);

  const freed = await until(() => pool.stats().running === 0, 3000);
  assert.ok(freed, '卡死的 worker 必须被硬超时回收，否则那条会话的后续邮件永远排队');
  assert.ok(lines.some((l) => l.includes('强杀')), `应记下强杀日志，实际:\n${lines.join('\n')}`);

  pool.submit('mail', { mail_id: 'after', session_id: 'STUCK', __hold: 30 });
  const ran = await until(() => jobs(lines).some((j) => j.mailID === 'after'), 2000);
  await until(() => pool.stats().running === 0);
  pool.stop();
  assert.ok(ran, '硬超时后同一会话的后续邮件必须能被处理');
});

test('权限决策路由到发起询问的那个 worker', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2 });
  pool.submit('mail', { mail_id: 'perm', session_id: 'PERM', __pending: 'rk-1' });
  await until(() => pool.stats().running === 1, 1500);
  await sleep(150);                              // 等 permission_pending 到主进程

  assert.equal(pool.routePermission('rk-1', '同意'), true, '应当路由成功');
  await until(() => pool.stats().running === 0, 2000);
  pool.stop();

  assert.ok(lines.some((l) => l.includes('DECISION rk-1=同意')),
    `worker 应收到决策原文，实际:\n${lines.join('\n')}`);
});

test('决策发的是选项原文而不是归一化的 allow/deny', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2 });
  pool.submit('mail', { mail_id: 'p2', session_id: 'P2', __pending: 'rk-2' });
  await until(() => pool.stats().running === 1, 1500);
  await sleep(150);
  pool.routePermission('rk-2', '一直同意');
  await until(() => pool.stats().running === 0, 2000);
  pool.stop();

  // 「同意」与「一直同意」语义不同，归一化会让后者退化成单次授权
  assert.ok(lines.some((l) => l.includes('DECISION rk-2=一直同意')),
    `必须原文透传，实际:\n${lines.join('\n')}`);
});

test('决策找不到 worker 时返回 false（调用方据此走 B-4.2 降级）', async () => {
  const { pool } = makePool();
  assert.equal(pool.routePermission('never-seen', '同意'), false);
  pool.stop();
});

test('worker 退出后它的权限路由被清掉，不会误投给下一个 worker', async () => {
  const { pool } = makePool({ maxWorkers: 2 });
  pool.submit('mail', { mail_id: 'gone', session_id: 'GONE', __pending: 'rk-gone' });
  await until(() => pool.stats().running === 1, 1500);
  await sleep(150);
  // 不给决策，直接停掉它
  pool.stop();
  await until(() => pool.stats().running === 0, 4000);

  assert.equal(pool.routePermission('rk-gone', '同意'), false,
    'worker 已退出，路由必须返回 false 让调用方走降级路径');
});

test('mailDrivenIDs 报出所有跑过的 pi 会话，且不随 worker 退出而清', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2 });
  pool.submit('mail', { mail_id: 'd1', session_id: 'D1', __hold: 30 });
  pool.submit('mail', { mail_id: 'd2', session_id: 'D2', __hold: 30 });
  await until(() => jobs(lines).length === 2 && pool.stats().running === 0);
  pool.stop();

  const ids = pool.mailDrivenIDs();
  assert.ok(ids.has('pi-d1'), 'D1 的 pi 会话该被标记为邮件驱动');
  assert.ok(ids.has('pi-d2'), 'D2 的 pi 会话该被标记为邮件驱动');
});

test('模型降级换掉的旧 pi 会话仍算邮件驱动', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2 });
  pool.submit('mail', { mail_id: 'r', session_id: 'RETIRE', __hold: 40, __reopen: 'pi-new' });
  await until(() => jobs(lines).length === 1 && pool.stats().running === 0);
  pool.stop();

  const ids = pool.mailDrivenIDs();
  assert.ok(ids.has('pi-new'), '新会话要在');
  assert.ok(ids.has('pi-r'), '被换掉的旧会话也参与过邮件往来，磁盘上的文件还在，快照该报它');
});

test('hasSession 只对跑过的邮件会话为真', async () => {
  const { pool } = makePool();
  assert.equal(pool.hasSession('NOPE'), false);
  pool.submit('mail', { mail_id: 'h1', session_id: 'HAS', __hold: 30 });
  await until(() => pool.hasSession('HAS'), 2000);
  await until(() => pool.stats().running === 0);
  pool.stop();
  assert.equal(pool.hasSession('HAS'), true, 'worker 退出后仍该记着这条会话');
});

test('kind 透传：权限通知走 permission 而不是 mail', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2 });
  pool.submit('permission', { mail_id: 'k1', session_id: 'K1', __hold: 20 });
  await until(() => jobs(lines).length === 1 && pool.stats().running === 0);
  pool.stop();
  assert.equal(jobs(lines)[0].kind, 'permission',
    'kind 决定 worker 用哪套提示词，传错会让模型以为收到一封新邮件');
});

test('stop 之后不再派活', async () => {
  const { pool } = makePool();
  pool.stop();
  pool.submit('mail', { mail_id: 'late', session_id: 'LATE', __hold: 30 });
  await sleep(200);
  assert.equal(pool.stats().running, 0, '关停后不该再起 worker');
  assert.equal(pool.stats().queued, 0, '关停后队列应为空');
});

test('stop 会先给 worker 发 shutdown（让它 fail closed）再杀', async () => {
  const { pool, lines } = makePool({ maxWorkers: 2 });
  pool.submit('mail', { mail_id: 's1', session_id: 'S1', __hold: -1 });
  await until(() => pool.stats().running === 1, 1500);
  pool.stop();
  const gotShutdown = await until(() => lines.some((l) => l.includes('SHUTDOWN')), 2000);
  assert.ok(gotShutdown,
    '必须先发 shutdown：直接 SIGKILL 会让 pi 侧那些等权限的 await 永不返回');
});

test('没有 session_id 的事件各占一个 key，不会互相串行', async () => {
  const { pool, lines } = makePool({ maxWorkers: 3 });
  pool.submit('mail', { mail_id: 'n1', __hold: 300 });
  pool.submit('mail', { mail_id: 'n2', __hold: 300 });
  const both = await until(() => ticks(lines, 'n1') >= 2 && ticks(lines, 'n2') >= 2, 2500);
  pool.stop();
  assert.ok(both, '无 session_id 的两封不属于同一条会话，应能并发');
});

test('reconfigure 上报被转达给主进程', async () => {
  const STUB2 = join(STUB_DIR, 'stub-reconf.mjs');
  writeFileSync(STUB2, `
process.on('message', (msg) => {
  if (msg?.type === 'job') {
    process.send({ type: 'reconfigure', url: 'http://new:9999', agentKey: 'k2' });
    process.send({ type: 'done', ok: true, error: '' });
    setTimeout(() => process.exit(0), 20);
  }
});
process.send({ type: 'ready' });
`);
  let got = null;
  const { pool } = makePool({
    maxWorkers: 1,
    workerPath: STUB2,
    onReconfigure: (url, key) => { got = { url, key }; },
  });
  pool.submit('mail', { mail_id: 'r1', session_id: 'R1' });
  await until(() => got !== null, 3000);
  pool.stop();
  assert.deepEqual(got, { url: 'http://new:9999', key: 'k2' },
    'worker 里 connect_to_server 换的坐标必须回到主进程 —— worker 马上就退了，改在它自己身上等于没改');
});