import { renderHook, act } from '@testing-library/react-native'
import { useDownloadMedia } from './use-download-media'
import * as FileSystem from 'expo-file-system'
import * as MediaLibrary from 'expo-media-library'

jest.mock('expo-file-system', () => ({
  documentDirectory: 'file:///mock/document/',
  createDownloadResumable: jest.fn(),
  deleteAsync: jest.fn(),
}))

jest.mock('expo-media-library', () => ({
  requestPermissionsAsync: jest.fn(),
  saveToLibraryAsync: jest.fn(),
}))

describe('useDownloadMedia', () => {
  beforeEach(() => {
    jest.clearAllMocks()
  })

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

  describe('initial state', () => {
    it('should return initial state', () => {
      const { result } = renderHook(() => useDownloadMedia())

      expect(result.current.loading).toBe(false)
      expect(result.current.error).toBeNull()
      expect(result.current.progress).toBe(0)
      expect(typeof result.current.download).toBe('function')
    })
  })

  describe('permission handling', () => {
    it('should return error when permission is denied', async () => {
      ;(MediaLibrary.requestPermissionsAsync as jest.Mock).mockResolvedValue({
        status: 'denied',
      })

      const { result } = renderHook(() => useDownloadMedia())

      let response
      await act(async () => {
        response = await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(response).toEqual({ success: false, error: 'Permission denied' })
      expect(result.current.error).toBe('Permission denied')
      expect(result.current.loading).toBe(false)
    })

    it('should proceed when permission is granted', async () => {
      ;(MediaLibrary.requestPermissionsAsync as jest.Mock).mockResolvedValue({
        status: 'granted',
      })

      const mockDownloadAsync = jest.fn().mockResolvedValue({ uri: 'file:///mock/document/download_123.jpg' })
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })
      ;(MediaLibrary.saveToLibraryAsync as jest.Mock).mockResolvedValue(undefined)
      ;(FileSystem.deleteAsync as jest.Mock).mockResolvedValue(undefined)

      const { result } = renderHook(() => useDownloadMedia())

      let response
      await act(async () => {
        response = await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(response).toEqual({ success: true })
      expect(MediaLibrary.requestPermissionsAsync).toHaveBeenCalled()
    })
  })

  describe('download functionality', () => {
    beforeEach(() => {
      ;(MediaLibrary.requestPermissionsAsync as jest.Mock).mockResolvedValue({
        status: 'granted',
      })
    })

    it('should download image successfully', async () => {
      const mockDownloadAsync = jest.fn().mockResolvedValue({ uri: 'file:///mock/document/download_123.jpg' })
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })
      ;(MediaLibrary.saveToLibraryAsync as jest.Mock).mockResolvedValue(undefined)
      ;(FileSystem.deleteAsync as jest.Mock).mockResolvedValue(undefined)

      const { result } = renderHook(() => useDownloadMedia())

      let response
      await act(async () => {
        response = await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(response).toEqual({ success: true })
      expect(FileSystem.createDownloadResumable).toHaveBeenCalledWith(
        'https://example.com/image.jpg',
        expect.stringMatching(/^file:\/\/\/mock\/document\/download_\d+\.jpg$/),
        {},
        expect.any(Function)
      )
      expect(MediaLibrary.saveToLibraryAsync).toHaveBeenCalled()
      expect(FileSystem.deleteAsync).toHaveBeenCalledWith(
        expect.stringMatching(/^file:\/\/\/mock\/document\/download_\d+\.jpg$/),
        { idempotent: true }
      )
    })

    it('should download video successfully', async () => {
      const mockDownloadAsync = jest.fn().mockResolvedValue({ uri: 'file:///mock/document/download_123.mp4' })
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })
      ;(MediaLibrary.saveToLibraryAsync as jest.Mock).mockResolvedValue(undefined)
      ;(FileSystem.deleteAsync as jest.Mock).mockResolvedValue(undefined)

      const { result } = renderHook(() => useDownloadMedia())

      let response
      await act(async () => {
        response = await result.current.download('https://example.com/video.mp4', 'video')
      })

      expect(response).toEqual({ success: true })
      expect(FileSystem.createDownloadResumable).toHaveBeenCalledWith(
        'https://example.com/video.mp4',
        expect.stringMatching(/^file:\/\/\/mock\/document\/download_\d+\.mp4$/),
        {},
        expect.any(Function)
      )
    })

    it('should handle download failure', async () => {
      const mockDownloadAsync = jest.fn().mockRejectedValue(new Error('Network error'))
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })

      const { result } = renderHook(() => useDownloadMedia())

      let response
      await act(async () => {
        response = await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(response).toEqual({ success: false, error: 'Network error' })
      expect(result.current.error).toBe('Network error')
    })

    it('should handle save to library failure', async () => {
      const mockDownloadAsync = jest.fn().mockResolvedValue({ uri: 'file:///mock/document/download_123.jpg' })
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })
      ;(MediaLibrary.saveToLibraryAsync as jest.Mock).mockRejectedValue(new Error('Save failed'))
      ;(FileSystem.deleteAsync as jest.Mock).mockResolvedValue(undefined)

      const { result } = renderHook(() => useDownloadMedia())

      let response
      await act(async () => {
        response = await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(response).toEqual({ success: false, error: 'Save failed' })
      expect(result.current.error).toBe('Save failed')
      // Should still attempt to clean up temp file
      expect(FileSystem.deleteAsync).toHaveBeenCalled()
    })
  })

  describe('loading state', () => {
    beforeEach(() => {
      ;(MediaLibrary.requestPermissionsAsync as jest.Mock).mockResolvedValue({
        status: 'granted',
      })
    })

    it('should set loading to true during download', async () => {
      let resolveDownload: (value: any) => void
      const downloadPromise = new Promise((resolve) => {
        resolveDownload = resolve
      })

      const mockDownloadAsync = jest.fn().mockReturnValue(downloadPromise)
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })
      ;(MediaLibrary.saveToLibraryAsync as jest.Mock).mockResolvedValue(undefined)
      ;(FileSystem.deleteAsync as jest.Mock).mockResolvedValue(undefined)

      const { result } = renderHook(() => useDownloadMedia())

      act(() => {
        result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(result.current.loading).toBe(true)

      await act(async () => {
        resolveDownload!({ uri: 'file:///mock/document/download_123.jpg' })
        await downloadPromise
      })

      expect(result.current.loading).toBe(false)
    })

    it('should set loading to false after error', async () => {
      const mockDownloadAsync = jest.fn().mockRejectedValue(new Error('Error'))
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })

      const { result } = renderHook(() => useDownloadMedia())

      await act(async () => {
        await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(result.current.loading).toBe(false)
    })
  })

  describe('progress tracking', () => {
    beforeEach(() => {
      ;(MediaLibrary.requestPermissionsAsync as jest.Mock).mockResolvedValue({
        status: 'granted',
      })
    })

    it('should update progress during download', async () => {
      let progressCallback: (progress: { totalBytesWritten: number; totalBytesExpectedToWrite: number }) => void

      const mockDownloadAsync = jest.fn().mockImplementation(async () => {
        // Simulate progress updates
        progressCallback({ totalBytesWritten: 50, totalBytesExpectedToWrite: 100 })
        return { uri: 'file:///mock/document/download_123.jpg' }
      })

      ;(FileSystem.createDownloadResumable as jest.Mock).mockImplementation(
        (url, fileUri, options, callback) => {
          progressCallback = callback
          return { downloadAsync: mockDownloadAsync }
        }
      )
      ;(MediaLibrary.saveToLibraryAsync as jest.Mock).mockResolvedValue(undefined)
      ;(FileSystem.deleteAsync as jest.Mock).mockResolvedValue(undefined)

      const { result } = renderHook(() => useDownloadMedia())

      await act(async () => {
        await result.current.download('https://example.com/image.jpg', 'image')
      })

      // Progress should be reset after completion
      expect(result.current.progress).toBe(0)
    })

    it('should reset progress on new download', async () => {
      const mockDownloadAsync = jest.fn().mockResolvedValue({ uri: 'file:///mock/document/download_123.jpg' })
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })
      ;(MediaLibrary.saveToLibraryAsync as jest.Mock).mockResolvedValue(undefined)
      ;(FileSystem.deleteAsync as jest.Mock).mockResolvedValue(undefined)

      const { result } = renderHook(() => useDownloadMedia())

      await act(async () => {
        await result.current.download('https://example.com/image1.jpg', 'image')
      })

      expect(result.current.progress).toBe(0)

      await act(async () => {
        await result.current.download('https://example.com/image2.jpg', 'image')
      })

      expect(result.current.progress).toBe(0)
    })
  })

  describe('error handling', () => {
    it('should clear error on new download attempt', async () => {
      ;(MediaLibrary.requestPermissionsAsync as jest.Mock)
        .mockResolvedValueOnce({ status: 'denied' })
        .mockResolvedValueOnce({ status: 'granted' })

      const mockDownloadAsync = jest.fn().mockResolvedValue({ uri: 'file:///mock/document/download_123.jpg' })
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })
      ;(MediaLibrary.saveToLibraryAsync as jest.Mock).mockResolvedValue(undefined)
      ;(FileSystem.deleteAsync as jest.Mock).mockResolvedValue(undefined)

      const { result } = renderHook(() => useDownloadMedia())

      await act(async () => {
        await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(result.current.error).toBe('Permission denied')

      await act(async () => {
        await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(result.current.error).toBeNull()
    })

    it('should handle unknown error types', async () => {
      ;(MediaLibrary.requestPermissionsAsync as jest.Mock).mockResolvedValue({
        status: 'granted',
      })

      const mockDownloadAsync = jest.fn().mockRejectedValue('Unknown error')
      ;(FileSystem.createDownloadResumable as jest.Mock).mockReturnValue({
        downloadAsync: mockDownloadAsync,
      })

      const { result } = renderHook(() => useDownloadMedia())

      let response
      await act(async () => {
        response = await result.current.download('https://example.com/image.jpg', 'image')
      })

      expect(response).toEqual({ success: false, error: 'Download failed' })
      expect(result.current.error).toBe('Download failed')
    })
  })
})