import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
import { DatabaseBackup } from '@/utils/backup'
import path from 'path'

// Mock pg-dump-restore
vi.mock('pg-dump-restore', () => ({
  pgDump: vi.fn().mockResolvedValue(undefined),
  pgRestore: vi.fn().mockResolvedValue(undefined),
}))


// Mock fs for tests
vi.mock('fs', () => ({
  promises: {
    mkdir: vi.fn().mockResolvedValue(undefined),
    chmod: vi.fn().mockResolvedValue(undefined),
    readdir: vi.fn().mockResolvedValue([]),
    stat: vi.fn().mockResolvedValue({ size: 1024, mtimeMs: Date.now(), mode: 0o600, mtime: new Date() }),
    access: vi.fn().mockResolvedValue(undefined),
    unlink: vi.fn().mockResolvedValue(undefined),
    rm: vi.fn().mockResolvedValue(undefined),
    writeFile: vi.fn().mockResolvedValue(undefined),
    utimes: vi.fn().mockResolvedValue(undefined),
  }
}))

// Mock logger
vi.mock('@/utils/logger', () => ({
  logger: {
    db: vi.fn(),
    error: vi.fn(),
    api: vi.fn(),
    middleware: vi.fn(),
  },
}))

describe('DatabaseBackup', () => {
  let backup: DatabaseBackup

  beforeEach(() => {
    vi.clearAllMocks()
    backup = DatabaseBackup.getInstance()
  })

  afterEach(() => {
    vi.restoreAllMocks()
  })

  describe('getInstance', () => {
    it('应该返回单例实例', () => {
      const instance1 = DatabaseBackup.getInstance()
      const instance2 = DatabaseBackup.getInstance()
      expect(instance1).toBe(instance2)
    })
  })

  describe('ensureBackupDir', () => {
    it('应该创建备份目录并设置权限', async () => {
      const fs = await import('fs')

      await backup.ensureBackupDir()

      expect(fs.promises.mkdir).toHaveBeenCalledWith('./backups', { recursive: true })
      expect(fs.promises.chmod).toHaveBeenCalledWith('./backups', 0o700)
    })

    it('应该在创建目录失败时抛出错误', async () => {
      const fs = await import('fs')
      const { logger } = await import('@/utils/logger')

      vi.mocked(fs.promises.mkdir).mockRejectedValueOnce(new Error('创建目录失败'))

      await expect(backup.ensureBackupDir()).rejects.toThrow('创建目录失败')
      expect(logger.error).toHaveBeenCalled()
    })
  })

  describe('getDbConfig', () => {
    it('应该返回正确的数据库配置', () => {
      process.env.DB_HOST = 'test-host'
      process.env.DB_PORT = '5433'
      process.env.DB_DATABASE = 'test-db'
      process.env.DB_USERNAME = 'test-user'
      process.env.DB_PASSWORD = 'test-password'

      const config = (backup as any).getDbConfig()

      expect(config).toEqual({
        host: 'test-host',
        port: 5433,
        database: 'test-db',
        username: 'test-user',
        password: 'test-password',
      })
    })

    it('应该使用默认值当环境变量未设置时', () => {
      delete process.env.DB_HOST
      delete process.env.DB_PORT
      delete process.env.DB_DATABASE
      delete process.env.DB_USERNAME
      delete process.env.DB_PASSWORD

      const config = (backup as any).getDbConfig()

      expect(config).toEqual({
        host: 'localhost',
        port: 5432,
        database: 'postgres',
        username: 'postgres',
        password: '',
      })
    })
  })

  describe('formatFileSize', () => {
    it('应该正确格式化文件大小', () => {
      const formatFileSize = (backup as any).formatFileSize

      expect(formatFileSize(0)).toBe('0 B')
      expect(formatFileSize(1024)).toBe('1 KB')
      expect(formatFileSize(1048576)).toBe('1 MB')
      expect(formatFileSize(1073741824)).toBe('1 GB')
    })
  })

  describe('backupExists', () => {
    it('应该返回true当备份文件存在时', async () => {
      const fs = await import('fs')

      const exists = await backup.backupExists('/path/to/backup.dump')

      expect(exists).toBe(true)
      expect(fs.promises.access).toHaveBeenCalledWith('/path/to/backup.dump')
    })

    it('应该返回false当备份文件不存在时', async () => {
      const fs = await import('fs')
      vi.mocked(fs.promises.access).mockRejectedValueOnce(new Error('文件不存在'))

      const exists = await backup.backupExists('/path/to/backup.dump')

      expect(exists).toBe(false)
    })
  })

  describe('cleanupOldBackups', () => {
    it('应该清理7天前的旧备份', async () => {
      const fs = await import('fs')
      const { logger } = await import('@/utils/logger')

      const now = Date.now()
      const oldFileTime = now - (8 * 24 * 60 * 60 * 1000) // 8天前
      const newFileTime = now - (6 * 24 * 60 * 60 * 1000) // 6天前

      vi.mocked(fs.promises.readdir).mockResolvedValue(['backup-old.dump', 'backup-new.dump'] as any)
      vi.mocked(fs.promises.stat)
        .mockResolvedValueOnce({ mtimeMs: oldFileTime } as any)
        .mockResolvedValueOnce({ mtimeMs: newFileTime } as any)

      await backup.cleanupOldBackups()

      expect(fs.promises.unlink).toHaveBeenCalledTimes(1)
      expect(fs.promises.unlink).toHaveBeenCalledWith(path.join('./backups', 'backup-old.dump'))
      expect(logger.db).toHaveBeenCalledWith('删除旧备份文件: backup-old.dump')
    })

    it('应该在清理失败时记录错误但不抛出', async () => {
      const fs = await import('fs')
      const { logger } = await import('@/utils/logger')

      vi.mocked(fs.promises.readdir).mockRejectedValueOnce(new Error('读取目录失败'))

      await expect(backup.cleanupOldBackups()).resolves.not.toThrow()
      expect(logger.error).toHaveBeenCalled()
    })
  })

  describe('startScheduledBackups', () => {
    it('应该启动定时备份任务', async () => {
      const { logger } = await import('@/utils/logger')

      backup.startScheduledBackups()

      // expect(cron.default.schedule).toHaveBeenCalledWith('0 2 * * *', expect.any(Function))
      expect(logger.db).toHaveBeenCalledWith('备份调度已启动: 0 2 * * *')
    })
  })

  describe('stopScheduledBackups', () => {
    it('应该停止定时备份任务', async () => {
      const { logger } = await import('@/utils/logger')

      // 先启动再停止
      backup.startScheduledBackups()
      backup.stopScheduledBackups()

      expect(logger.db).toHaveBeenCalledWith('备份调度已停止')
    })
  })
})