/**
 * redisClient.js 单元测试
 * 覆盖：连接状态、对话历史读写、KB缓存读写、降级行为、TTL/LTRIM逻辑
 *
 * 运行方式: node --test tests/test_redis_client.js
 * 注意: 需要本地Redis可用（redis://127.0.0.1:6379），否则降级测试仍会通过
 */
const { describe, it, beforeEach, afterEach } = require('node:test');
const assert = require('node:assert/strict');
const path = require('path');
const fs = require('fs');

// 加载 .env
const envPath = path.join(__dirname, '../.env');
if (fs.existsSync(envPath)) {
  fs.readFileSync(envPath, 'utf8').split('\n').forEach(line => {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('#')) return;
    const idx = trimmed.indexOf('=');
    if (idx > 0) {
      const key = trimmed.slice(0, idx).trim();
      let val = trimmed.slice(idx + 1).trim();
      if ((val.startsWith('"') && val.endsWith('"')) || (val.startsWith("'") && val.endsWith("'"))) {
        val = val.slice(1, -1);
      }
      if (!process.env[key]) process.env[key] = val;
    }
  });
}

const { after } = require('node:test');
const redisClient = require('../services/redisClient');

const TEST_SESSION_ID = `test_session_${Date.now()}_${Math.random().toString(36).slice(2, 8)}`;
const TEST_KB_CACHE_KEY = `test_kb_cache_${Date.now()}`;

// 测试结束后断开 Redis，防止进程挂起
after(async () => {
  await redisClient.disconnect();
});

// ================================================================
// 1. 连接与可用性
// ================================================================
describe('redisClient — 连接与可用性', () => {
  it('createClient 应返回客户端实例', () => {
    const client = redisClient.createClient();
    assert.ok(client, 'createClient should return a client');
  });

  it('getClient 应返回同一个实例（单例模式）', () => {
    const c1 = redisClient.getClient();
    const c2 = redisClient.getClient();
    assert.strictEqual(c1, c2, 'getClient should return singleton');
  });

  it('isAvailable 应返回 boolean', () => {
    const result = redisClient.isAvailable();
    assert.equal(typeof result, 'boolean', 'isAvailable should return boolean');
  });
});

// ================================================================
// 2. 对话历史 — pushMessage + getRecentHistory
// ================================================================
describe('redisClient — 对话历史读写', () => {
  const sessionId = TEST_SESSION_ID;

  beforeEach(async () => {
    await redisClient.clearSession(sessionId);
  });

  afterEach(async () => {
    await redisClient.clearSession(sessionId);
  });

  it('pushMessage 写入后 getRecentHistory 应能读取', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    const ok = await redisClient.pushMessage(sessionId, { role: 'user', content: '你好' });
    assert.equal(ok, true, 'pushMessage should return true');

    const history = await redisClient.getRecentHistory(sessionId, 5);
    assert.ok(Array.isArray(history), 'getRecentHistory should return array');
    assert.equal(history.length, 1, 'Should have 1 message');
    assert.equal(history[0].role, 'user');
    assert.equal(history[0].content, '你好');
  });

  it('多条消息应保持时间顺序（最旧在前）', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    await redisClient.pushMessage(sessionId, { role: 'user', content: '第1条' });
    await redisClient.pushMessage(sessionId, { role: 'assistant', content: '第2条' });
    await redisClient.pushMessage(sessionId, { role: 'user', content: '第3条' });

    const history = await redisClient.getRecentHistory(sessionId, 5);
    assert.equal(history.length, 3);
    assert.equal(history[0].content, '第1条', '最旧的应在前面');
    assert.equal(history[1].content, '第2条');
    assert.equal(history[2].content, '第3条', '最新的应在后面');
  });

  it('超过10条应自动截断（LTRIM），只保留最近10条', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    for (let i = 1; i <= 15; i++) {
      await redisClient.pushMessage(sessionId, { role: i % 2 === 1 ? 'user' : 'assistant', content: `第${i}条` });
    }

    const history = await redisClient.getRecentHistory(sessionId, 10);
    assert.ok(history.length <= 10, `Should have at most 10 messages, got ${history.length}`);
    // 最旧的应该是第6条（前5条被截断）
    assert.equal(history[0].content, '第6条', '最旧的应该是第6条');
    assert.equal(history[history.length - 1].content, '第15条', '最新的应该是第15条');
  });

  it('getRecentHistory maxRounds 参数应限制返回数量', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    for (let i = 1; i <= 8; i++) {
      await redisClient.pushMessage(sessionId, { role: i % 2 === 1 ? 'user' : 'assistant', content: `消息${i}` });
    }

    const history2 = await redisClient.getRecentHistory(sessionId, 2);
    assert.ok(history2.length <= 4, `maxRounds=2 should return at most 4 messages, got ${history2.length}`);
  });

  it('clearSession 后 getRecentHistory 应返回空', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    await redisClient.pushMessage(sessionId, { role: 'user', content: '会被清除' });
    await redisClient.clearSession(sessionId);
    const history = await redisClient.getRecentHistory(sessionId, 5);
    assert.equal(history.length, 0, 'Should be empty after clear');
  });

  it('消息应包含 ts 时间戳', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    const before = Date.now();
    await redisClient.pushMessage(sessionId, { role: 'user', content: '带时间戳' });
    const after = Date.now();

    const history = await redisClient.getRecentHistory(sessionId, 1);
    assert.ok(history[0].ts >= before && history[0].ts <= after, 'ts should be within time range');
  });
});

// ================================================================
// 3. KB缓存读写
// ================================================================
describe('redisClient — KB缓存读写', () => {
  const cacheKey = TEST_KB_CACHE_KEY;

  afterEach(async () => {
    if (redisClient.isAvailable()) {
      try {
        const client = redisClient.getClient();
        await client.del(`kb_cache:${cacheKey}`);
      } catch {}
    }
  });

  it('setKbCache + getKbCache 应正确读写', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    const result = { hit: true, query: '测试', results: [{ content: '测试内容' }] };
    const ok = await redisClient.setKbCache(cacheKey, result);
    assert.equal(ok, true, 'setKbCache should return true');

    const cached = await redisClient.getKbCache(cacheKey);
    assert.ok(cached, 'getKbCache should return data');
    assert.equal(cached.hit, true);
    assert.equal(cached.query, '测试');
  });

  it('不存在的key应返回null', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    const cached = await redisClient.getKbCache('nonexistent_key_' + Date.now());
    assert.equal(cached, null, 'Should return null for nonexistent key');
  });
});

// ================================================================
// 4. 降级行为（Redis不可用时）
// ================================================================
describe('redisClient — 降级行为', () => {
  it('pushMessage 在 Redis 不可用时应返回 false 而非报错', async () => {
    // 即使 Redis 可用，这也验证接口契约
    const result = await redisClient.pushMessage('fake_session', { role: 'user', content: 'test' });
    assert.equal(typeof result, 'boolean', 'Should return boolean');
  });

  it('getRecentHistory 在不存在的 session 应返回空数组', async () => {
    const result = await redisClient.getRecentHistory('nonexistent_session_' + Date.now(), 5);
    if (result === null) {
      // Redis不可用的降级
      assert.equal(result, null);
    } else {
      assert.ok(Array.isArray(result), 'Should return array');
      assert.equal(result.length, 0, 'Should be empty for nonexistent session');
    }
  });

  it('clearSession 对不存在的 session 不应报错', async () => {
    const result = await redisClient.clearSession('nonexistent_session_' + Date.now());
    assert.equal(typeof result, 'boolean', 'Should return boolean');
  });

  it('getKbCache 在 Redis 不可用时应返回 null', async () => {
    const result = await redisClient.getKbCache('test_key');
    // 无论 Redis 是否可用，都不应抛出异常
    assert.ok(result === null || typeof result === 'object', 'Should return null or object');
  });

  it('setKbCache 在 Redis 不可用时应返回 false', async () => {
    const result = await redisClient.setKbCache('test_key', { hit: false });
    assert.equal(typeof result, 'boolean', 'Should return boolean');
  });
});

// ================================================================
// 5. 数据完整性
// ================================================================
describe('redisClient — 数据完整性', () => {
  const sessionId = TEST_SESSION_ID + '_integrity';

  afterEach(async () => {
    await redisClient.clearSession(sessionId);
  });

  it('特殊字符消息应正确存取', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    const specialContent = '产品价格：¥299.00 "双引号" \'单引号\' \n换行 \t制表符 emoji🎉';
    await redisClient.pushMessage(sessionId, { role: 'user', content: specialContent });

    const history = await redisClient.getRecentHistory(sessionId, 1);
    assert.equal(history[0].content, specialContent, 'Should preserve special characters');
  });

  it('空内容消息应正确存取', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    await redisClient.pushMessage(sessionId, { role: 'user', content: '' });
    const history = await redisClient.getRecentHistory(sessionId, 1);
    assert.equal(history[0].content, '', 'Should handle empty content');
  });

  it('source 字段应正确保存', async () => {
    if (!redisClient.isAvailable()) {
      console.log('  ⏭️  Redis不可用，跳过');
      return;
    }

    await redisClient.pushMessage(sessionId, { role: 'assistant', content: '回答', source: 'voice_tool' });
    const history = await redisClient.getRecentHistory(sessionId, 1);
    assert.equal(history[0].source, 'voice_tool', 'Should preserve source field');
  });
});

console.log('\n=== redisClient 测试加载完成 ===\n');