import { expect } from 'chai'
import db, { DbQueryCache, checkDatabaseHealth, getDatabaseStats } from '../../src/db/index.js'
import { UserModel } from '../../src/db/models/UserModel.js'
import { logQuery, getQueryStats, getSlowQueries, resetStats } from '../../src/db/monitor.js'

describe('Database Performance', () => {
    before(() => {
        // 重置统计
        resetStats()
    })

    describe('Connection Pool', () => {
        it('应该保持健康的数据库连接', async () => {
            const health = await checkDatabaseHealth()
            expect(health.status).to.equal('healthy')
            expect(health).to.have.property('responseTime')
            expect(health.responseTime).to.be.a('number')
        })

        it('应该正确报告连接池状态', async () => {
            const stats = getDatabaseStats()
            expect(stats).to.have.property('connectionPool')
            expect(stats.connectionPool).to.have.property('min')
            expect(stats.connectionPool).to.have.property('max')
            expect(stats.connectionPool).to.have.property('used')
        })
    })

    describe('Query Performance', () => {
        beforeEach(async () => {
            // 清空用户表
            await db('users').del()
        })

        it('应该正确记录查询统计', async () => {
            const initialStats = getQueryStats()
            
            // 执行一些查询
            await UserModel.create({
                username: 'perf_test',
                email: 'perf_test@example.com',
                password: 'password123'
            })
            
            await UserModel.findByUsername('perf_test')
            await UserModel.findAll()
            
            const finalStats = getQueryStats()
            expect(finalStats.totalQueries).to.be.greaterThan(initialStats.totalQueries)
        })

        it('应该正确处理缓存查询', async () => {
            // 清空缓存
            DbQueryCache.clear()
            
            const cacheStatsBefore = DbQueryCache.stats()
            
            // 执行带缓存的查询
            const query = db('users').select('*').cache(1000) // 1秒缓存
            await query
            
            const cacheStatsAfter = DbQueryCache.stats()
            expect(cacheStatsAfter.valid).to.be.greaterThan(cacheStatsBefore.valid)
        })

        it('应该正确识别慢查询', async function() {
            this.timeout(5000) // 增加超时时间
            
            // 清空慢查询记录
            resetStats()
            
            // 执行一个可能较慢的查询（通过复杂连接）
            try {
                const result = await db.raw(`
                    SELECT u1.*, u2.username as related_user
                    FROM users u1
                    LEFT JOIN users u2 ON u1.id != u2.id
                    WHERE u1.id IN (
                        SELECT id FROM users 
                        WHERE username LIKE '%test%' 
                        ORDER BY id
                    )
                    ORDER BY u1.id, u2.id
                    LIMIT 100
                `)
            } catch (error) {
                // 忽略查询错误
            }
            
            // 检查是否有慢查询记录
            const slowQueries = getSlowQueries()
            // 注意：由于测试环境可能很快，不一定能触发慢查询
        })
    })

    describe('Cache Performance', () => {
        it('应该正确管理缓存统计', async () => {
            const cacheStats = DbQueryCache.stats()
            expect(cacheStats).to.have.property('size')
            expect(cacheStats).to.have.property('valid')
            expect(cacheStats).to.have.property('expired')
        })

        it('应该正确清理过期缓存', async () => {
            // 添加一些带短生命周期的缓存项
            DbQueryCache.set('test_key_1', 'test_value_1', 10) // 10ms过期
            DbQueryCache.set('test_key_2', 'test_value_2', 5000) // 5秒过期
            
            // 等待第一个缓存项过期
            await new Promise(resolve => setTimeout(resolve, 20))
            
            const cleaned = DbQueryCache.cleanup()
            expect(cleaned).to.be.greaterThanOrEqual(0)
        })

        it('应该按前缀清理缓存', async () => {
            DbQueryCache.set('user:123', 'user_data')
            DbQueryCache.set('user:456', 'user_data')
            DbQueryCache.set('post:123', 'post_data')
            
            const before = DbQueryCache.stats()
            DbQueryCache.clearByPrefix('user:')
            const after = DbQueryCache.stats()
            
            expect(after.valid).to.be.lessThan(before.valid)
        })
    })

    describe('Memory Usage', () => {
        it('应该报告缓存内存使用情况', async () => {
            // 添加一些测试数据到缓存
            DbQueryCache.set('memory_test_1', { data: 'test data 1', timestamp: Date.now() })
            DbQueryCache.set('memory_test_2', { data: 'test data 2 with more content', timestamp: Date.now() })
            
            const memoryUsage = DbQueryCache.getMemoryUsage()
            expect(memoryUsage).to.have.property('entryCount')
            expect(memoryUsage).to.have.property('totalMemoryBytes')
            expect(memoryUsage).to.have.property('averageEntrySize')
            expect(memoryUsage).to.have.property('estimatedMemoryMB')
        })
    })
})