/**
 * 平台服务冒烟测试（任务 A1.3）。
 *
 * 打通「建会话 → 发消息 → 事件流推送」这条链路，并顺带验证协议里写死的几条规则：
 *   1. 未接入任何 Provider 时平台也能正常启动（ADR-0009）
 *   2. 事件符合 contracts/schemas/events.schema.json，seq 会话内单调递增
 *   3. 同一幂等键重试不产生第二个 run
 *   4. 取消能把运行停下，并推 cancelling → completed(cancelled) → idle
 *   5. 断点续传：since 能回放
 *   6. 错误走 ErrorEnvelope；个人会话不允许带 projectId
 */
import assert from 'node:assert/strict';
import { readFile, readdir } from 'node:fs/promises';
import { join } from 'node:path';
import { test } from 'node:test';
import { fileURLToPath } from 'node:url';

import Ajv2020 from 'ajv/dist/2020.js';

const ROOT = fileURLToPath(new URL('..', import.meta.url));
const EVENTS_SCHEMA_ID = 'https://aps.local/contracts/events.schema.json';

async function validator() {
  const ajv = new Ajv2020({ allErrors: true, strict: false });
  for (const name of await readdir(join(ROOT, 'contracts', 'schemas'))) {
    if (!name.endsWith('.json')) continue;
    ajv.addSchema(JSON.parse(await readFile(join(ROOT, 'contracts', 'schemas', name), 'utf8')));
  }
  return ajv.getSchema(EVENTS_SCHEMA_ID);
}

async function startServer() {
  const { startServer: start } = await import('../server/dist/index.js');
  return start({ host: '127.0.0.1', port: 0, version: 'test' });
}

const json = (method, body) => ({ method, headers: { 'content-type': 'application/json' }, body: JSON.stringify(body) });
const post = (base, path, body) => fetch(`${base}${path}`, json('POST', body));
const get = (base, path) => fetch(`${base}${path}`);

async function openStream(base, sessionId, query = '') {
  const controller = new AbortController();
  const response = await fetch(`${base}/v1/sessions/${sessionId}/events${query}`, {
    headers: { accept: 'text/event-stream' },
    signal: controller.signal,
  });
  assert.equal(response.status, 200, '事件流应返回 200');
  const events = [];
  void (async () => {
    const decoder = new TextDecoder();
    let buffer = '';
    try {
      for await (const chunk of response.body) {
        buffer += decoder.decode(chunk, { stream: true });
        let index = buffer.indexOf('\n\n');
        while (index >= 0) {
          const frame = buffer.slice(0, index);
          buffer = buffer.slice(index + 2);
          const dataLine = frame.split('\n').find((line) => line.startsWith('data: '));
          if (dataLine) events.push(JSON.parse(dataLine.slice(6)));
          index = buffer.indexOf('\n\n');
        }
      }
    } catch {
      /* aborted */
    }
  })();

  return {
    events,
    close: () => controller.abort(),
    async waitFor(predicate, label, timeoutMs = 6000) {
      const deadline = Date.now() + timeoutMs;
      while (Date.now() < deadline) {
        const hit = predicate(events);
        if (hit) return hit;
        await new Promise((resolve) => setTimeout(resolve, 20));
      }
      throw new Error(`超时等待「${label}」；已收到：${events.map((event) => event.type).join(',') || '（无）'}`);
    },
  };
}

const findIdleAfterCompleted = (events) =>
  events.some((event) => event.type === 'message.completed') && events.some((event) => event.type === 'run.state' && event.data.state === 'idle');

async function createProjectSession(base, title = '冒烟会话') {
  const response = await post(base, '/v1/sessions', { scope: 'project', projectId: 'p-default', title });
  assert.equal(response.status, 200);
  const body = await response.json();
  return body.session;
}

test('未接入业务系统时平台可用：健康检查、身份、项目、能力清单', async () => {
  const server = await startServer();
  try {
    const health = await (await get(server.url, '/v1/health')).json();
    assert.equal(health.status, 'ok');
    assert.equal(health.protocolVersion, 1);
    assert.equal(typeof health.version, 'string');

    const me = await (await get(server.url, '/v1/me')).json();
    assert.equal(me.userId, 'dev-user');
    assert.equal(me.clientKind, 'browser');

    const projects = await (await get(server.url, '/v1/projects')).json();
    assert.ok(Array.isArray(projects.projects) && projects.projects.length >= 1, '应有默认项目');

    const capabilities = await (await get(server.url, '/v1/capabilities')).json();
    assert.ok(Array.isArray(capabilities.capabilities), '能力清单应是数组');
    assert.equal(capabilities.capabilities.length, 0, '未接入 Provider 时能力清单为空');
  } finally {
    await server.close();
  }
});

test('建会话 → 发消息 → 事件流按协议推送且样例合规', async () => {
  const validateEvent = await validator();
  assert.ok(validateEvent);
  const server = await startServer();
  try {
    const session = await createProjectSession(server.url);
    const stream = await openStream(server.url, session.sessionId);
    const accepted = await post(server.url, `/v1/sessions/${session.sessionId}/messages`, {
      text: '试排一版看看',
      idempotencyKey: 'idem-smoke-0001',
    });
    assert.equal(accepted.status, 202);
    const acceptedBody = await accepted.json();
    assert.equal(acceptedBody.accepted, true);
    assert.ok(acceptedBody.runId.startsWith('r-'));

    await stream.waitFor(findIdleAfterCompleted, '回合结束');
    stream.close();

    const types = stream.events.map((event) => event.type);
    assert.equal(types[0], 'message.user', `第一条应为 message.user，实际 ${types[0]}`);
    assert.ok(types.includes('message.delta'), '应收到增量文本');
    assert.ok(types.includes('run.state'), '应收到运行状态');

    let lastSeq = 0;
    for (const event of stream.events) {
      assert.ok(validateEvent(event), `${event.type} 不符合 events.schema.json：${JSON.stringify(validateEvent.errors)}`);
      assert.equal(event.v, 1);
      assert.ok(event.seq > lastSeq, 'seq 必须严格递增');
      lastSeq = event.seq;
      assert.equal(event.sessionId, session.sessionId);
    }

    const detail = await (await get(server.url, `/v1/sessions/${session.sessionId}`)).json();
    assert.equal(detail.messages.length, 2, '会话详情应含用户与助手两条消息');
    assert.equal(detail.messages[0].role, 'user');
    assert.equal(detail.messages[1].role, 'assistant');
    assert.match(detail.messages[1].text, /A1 占位引擎/);
  } finally {
    await server.close();
  }
});

test('同一幂等键重试不产生第二个 run', async () => {
  const server = await startServer();
  try {
    const session = await createProjectSession(server.url);
    const stream = await openStream(server.url, session.sessionId);
    const body = { text: '幂等重试', idempotencyKey: 'idem-smoke-0002' };
    const first = await (await post(server.url, `/v1/sessions/${session.sessionId}/messages`, body)).json();
    const second = await post(server.url, `/v1/sessions/${session.sessionId}/messages`, body);
    assert.equal(second.status, 202, '重试不应报冲突');
    const secondBody = await second.json();
    assert.equal(secondBody.runId, first.runId, '重试应返回同一个 runId');
    assert.equal(secondBody.messageId, first.messageId);

    await stream.waitFor(findIdleAfterCompleted, '回合结束');
    stream.close();
    const userEvents = stream.events.filter((event) => event.type === 'message.user');
    assert.equal(userEvents.length, 1, '重试不应产生第二条 message.user');
  } finally {
    await server.close();
  }
});

test('取消正在运行的回合', async () => {
  const server = await startServer();
  try {
    const session = await createProjectSession(server.url);
    const stream = await openStream(server.url, session.sessionId);
    await post(server.url, `/v1/sessions/${session.sessionId}/messages`, { text: '取消我', idempotencyKey: 'idem-smoke-0003' });
    const cancel = await post(server.url, `/v1/sessions/${session.sessionId}/cancel`, {});
    assert.equal(cancel.status, 200);
    await stream.waitFor(
      (events) => events.some((event) => event.type === 'run.state' && event.data.state === 'cancelling') && findIdleAfterCompleted(events),
      '取消完成',
    );
    stream.close();
    const completed = stream.events.find((event) => event.type === 'message.completed');
    assert.equal(completed.data.finishReason, 'cancelled');
  } finally {
    await server.close();
  }
});

test('断点续传：since 能回放已有事件', async () => {
  const server = await startServer();
  try {
    const session = await createProjectSession(server.url);
    const stream = await openStream(server.url, session.sessionId);
    await post(server.url, `/v1/sessions/${session.sessionId}/messages`, { text: '回放用', idempotencyKey: 'idem-smoke-0004' });
    await stream.waitFor(findIdleAfterCompleted, '回合结束');
    stream.close();

    const replay = await openStream(server.url, session.sessionId, '?since=1');
    await replay.waitFor((events) => events.length > 0, '回放事件');
    replay.close();
    assert.ok(replay.events.every((event) => event.seq > 1), '回放只应包含 since 之后的事件');
    assert.equal(replay.events[0].seq, 2);
  } finally {
    await server.close();
  }
});

test('错误走 ErrorEnvelope；个人会话不允许带 projectId', async () => {
  const server = await startServer();
  try {
    const missing = await get(server.url, '/v1/nope');
    assert.equal(missing.status, 404);
    const missingBody = await missing.json();
    assert.equal(missingBody.error.code, 'not_found');
    assert.equal(typeof missingBody.error.retryable, 'boolean');

    const invalid = await post(server.url, '/v1/sessions', { scope: 'personal', projectId: 'p-default' });
    assert.equal(invalid.status, 400);
    const invalidBody = await invalid.json();
    assert.equal(invalidBody.error.code, 'invalid_request');

    const notImplemented = await get(server.url, '/v1/executions/exec-x');
    assert.equal(notImplemented.status, 501);
    const notImplementedBody = await notImplemented.json();
    assert.equal(notImplementedBody.error.code, 'not_implemented');
  } finally {
    await server.close();
  }
});