package media_test

import (
	"bytes"
	"context"
	"database/sql"
	"errors"
	"io"
	"strings"
	"testing"
	"time"

	"git.netflux.io/rob/clipper/config"
	"git.netflux.io/rob/clipper/generated/mocks"
	"git.netflux.io/rob/clipper/generated/store"
	"git.netflux.io/rob/clipper/media"
	"github.com/google/uuid"
	"github.com/kkdai/youtube/v2"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap"
)

func TestGetVideoFromYoutube(t *testing.T) {
	ctx := context.Background()
	logger := zap.NewNop().Sugar()

	const (
		itag               = 234
		videoID            = "video001"
		videoMimeType      = "video/mp4"
		videoContentLength = int64(100_000)
	)
	mediaSetID := uuid.New()
	mediaSet := store.MediaSet{
		ID:               mediaSetID,
		YoutubeID:        videoID,
		VideoYoutubeItag: int32(itag),
	}

	video := &youtube.Video{
		ID:      videoID,
		Formats: []youtube.Format{{ItagNo: itag, FPS: 30, AudioChannels: 0, MimeType: videoMimeType, ContentLength: videoContentLength}},
	}

	t.Run("NOK,ErrorFetchingVideo", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)

		var youtubeClient mocks.YoutubeClient
		youtubeClient.On("GetVideoContext", ctx, videoID).Return(nil, errors.New("nope"))

		service := media.NewMediaSetService(&mockStore, &youtubeClient, nil, nil, config.Config{}, logger)
		_, err := service.GetVideo(ctx, mediaSetID)
		assert.EqualError(t, err, "error fetching video: nope")
	})

	t.Run("NOK,ErrorFetchingStream", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)

		var youtubeClient mocks.YoutubeClient
		youtubeClient.On("GetVideoContext", ctx, videoID).Return(video, nil)
		youtubeClient.On("GetStreamContext", ctx, video, &video.Formats[0]).Return(nil, int64(0), errors.New("network failure"))

		service := media.NewMediaSetService(&mockStore, &youtubeClient, nil, nil, config.Config{}, logger)
		_, err := service.GetVideo(ctx, mediaSetID)
		assert.EqualError(t, err, "error fetching stream: network failure")
	})

	t.Run("NOK,ErrorPuttingObjectInFileStore", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)

		encodedContent := "a video stream"
		reader := io.NopCloser(strings.NewReader(encodedContent))

		var youtubeClient mocks.YoutubeClient
		youtubeClient.On("GetVideoContext", ctx, videoID).Return(video, nil)
		youtubeClient.On("GetStreamContext", ctx, video, &video.Formats[0]).Return(reader, int64(len(encodedContent)), nil)

		var fileStore mocks.FileStore
		fileStore.On("PutObject", ctx, mock.Anything, mock.Anything, videoMimeType).Return(int64(0), errors.New("error storing object"))

		service := media.NewMediaSetService(&mockStore, &youtubeClient, &fileStore, nil, config.Config{}, logger)
		stream, err := service.GetVideo(ctx, mediaSetID)
		require.NoError(t, err)

		_, err = stream.Next()
		assert.EqualError(t, err, "error waiting for progress: error uploading to file store: error storing object")
	})

	t.Run("NOK,ErrorClosingStream", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)

		encodedContent := "a video stream"
		reader := errorCloser{Reader: strings.NewReader(encodedContent)}

		var youtubeClient mocks.YoutubeClient
		youtubeClient.On("GetVideoContext", ctx, videoID).Return(video, nil)
		youtubeClient.On("GetStreamContext", ctx, video, &video.Formats[0]).Return(reader, int64(len(encodedContent)), nil)

		var fileStore mocks.FileStore
		fileStore.On("PutObject", ctx, mock.Anything, mock.Anything, videoMimeType).Return(int64(len(encodedContent)), nil)

		service := media.NewMediaSetService(&mockStore, &youtubeClient, &fileStore, nil, config.Config{}, logger)
		stream, err := service.GetVideo(ctx, mediaSetID)
		require.NoError(t, err)

		_, err = stream.Next()
		assert.EqualError(t, err, "error waiting for progress: error closing video stream: close error")
	})

	t.Run("NOK,ErrorGettingObjectURL", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)

		encodedContent := "a video stream"
		reader := io.NopCloser(strings.NewReader(encodedContent))

		var youtubeClient mocks.YoutubeClient
		youtubeClient.On("GetVideoContext", ctx, videoID).Return(video, nil)
		youtubeClient.On("GetStreamContext", ctx, video, &video.Formats[0]).Return(reader, int64(len(encodedContent)), nil)

		var fileStore mocks.FileStore
		fileStore.On("PutObject", ctx, mock.Anything, mock.Anything, videoMimeType).Return(int64(len(encodedContent)), nil)
		fileStore.On("GetURL", ctx, mock.Anything).Return("", errors.New("URL error"))

		service := media.NewMediaSetService(&mockStore, &youtubeClient, &fileStore, nil, config.Config{}, logger)
		stream, err := service.GetVideo(ctx, mediaSetID)
		require.NoError(t, err)

		_, err = stream.Next()
		assert.EqualError(t, err, "error waiting for progress: error getting object URL: URL error")
	})

	t.Run("NOK,ErrorUpdatingStore", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)
		mockStore.On("SetVideoUploaded", ctx, mock.Anything).Return(mediaSet, errors.New("boom"))

		encodedContent := "a video stream"
		reader := io.NopCloser(strings.NewReader(encodedContent))

		var youtubeClient mocks.YoutubeClient
		youtubeClient.On("GetVideoContext", ctx, videoID).Return(video, nil)
		youtubeClient.On("GetStreamContext", ctx, video, &video.Formats[0]).Return(reader, int64(len(encodedContent)), nil)

		var fileStore mocks.FileStore
		fileStore.On("PutObject", ctx, mock.Anything, mock.Anything, videoMimeType).Return(int64(len(encodedContent)), nil)
		fileStore.On("GetURL", ctx, mock.Anything).Return("a url", nil)

		service := media.NewMediaSetService(&mockStore, &youtubeClient, &fileStore, nil, config.Config{}, logger)
		stream, err := service.GetVideo(ctx, mediaSetID)
		require.NoError(t, err)

		_, err = stream.Next()
		assert.EqualError(t, err, "error waiting for progress: error saving to store: boom")
	})

	t.Run("OK", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)
		mockStore.On("SetVideoUploaded", ctx, mock.Anything).Return(mediaSet, nil)
		defer mockStore.AssertExpectations(t)

		encodedContent := make([]byte, videoContentLength)
		reader := io.NopCloser(bytes.NewReader(encodedContent))

		var youtubeClient mocks.YoutubeClient
		youtubeClient.On("GetVideoContext", ctx, videoID).Return(video, nil)
		youtubeClient.On("GetStreamContext", ctx, video, &video.Formats[0]).Return(reader, videoContentLength, nil)
		defer youtubeClient.AssertExpectations(t)

		var fileStore mocks.FileStore
		fileStore.On("PutObject", ctx, mock.Anything, mock.Anything, videoMimeType).
			Run(func(args mock.Arguments) {
				n, err := io.Copy(io.Discard, args[2].(io.Reader))
				require.NoError(t, err)
				assert.Equal(t, videoContentLength, n)
			}).
			Return(videoContentLength, nil)
		fileStore.On("GetURL", ctx, mock.Anything).Return("a url", nil)
		defer fileStore.AssertExpectations(t)

		service := media.NewMediaSetService(&mockStore, &youtubeClient, &fileStore, nil, config.Config{}, logger)
		stream, err := service.GetVideo(ctx, mediaSetID)
		require.NoError(t, err)

		var (
			lastPercentComplete float32
			lastURL             string
		)

		for {
			progress, err := stream.Next()
			if err != io.EOF {
				require.NoError(t, err)
			}

			assert.GreaterOrEqual(t, progress.PercentComplete, lastPercentComplete)
			lastPercentComplete = progress.PercentComplete
			lastURL = progress.URL

			if err == io.EOF {
				break
			}
		}

		assert.Equal(t, float32(100), lastPercentComplete)
		assert.Equal(t, "a url", lastURL)
	})
}

type errorCloser struct {
	io.Reader
}

func (c errorCloser) Close() error { return errors.New("close error") }

func TestGetVideoFromFileStore(t *testing.T) {
	ctx := context.Background()
	logger := zap.NewNop().Sugar()

	videoID := "video002"
	mediaSetID := uuid.New()
	mediaSet := store.MediaSet{
		ID:                mediaSetID,
		YoutubeID:         videoID,
		VideoS3UploadedAt: sql.NullTime{Time: time.Now(), Valid: true},
		VideoS3Key:        sql.NullString{String: "videos/myvideo", Valid: true},
	}

	t.Run("NOK,ErrorFetchingMediaSet", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(store.MediaSet{}, errors.New("database fail"))

		service := media.NewMediaSetService(&mockStore, nil, nil, nil, config.Config{}, logger)
		_, err := service.GetVideo(ctx, mediaSetID)
		require.EqualError(t, err, "error getting media set: database fail")
	})

	t.Run("NOK,ErrorGettingObjectURL", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)

		var fileStore mocks.FileStore
		fileStore.On("GetURL", ctx, "videos/myvideo").Return("", errors.New("key missing"))

		service := media.NewMediaSetService(&mockStore, nil, &fileStore, nil, config.Config{}, logger)
		_, err := service.GetVideo(ctx, mediaSetID)
		require.EqualError(t, err, "error generating presigned URL: key missing")
	})

	t.Run("OK", func(t *testing.T) {
		var mockStore mocks.Store
		mockStore.On("GetMediaSet", ctx, mediaSetID).Return(mediaSet, nil)

		const url = "https://www.example.com/audio"
		var fileStore mocks.FileStore
		fileStore.On("GetURL", ctx, "videos/myvideo").Return(url, nil)

		service := media.NewMediaSetService(&mockStore, nil, &fileStore, nil, config.Config{}, logger)
		stream, err := service.GetVideo(ctx, mediaSetID)
		require.NoError(t, err)

		progress, err := stream.Next()
		assert.Equal(t, float32(100), progress.PercentComplete)
		assert.Equal(t, url, progress.URL)
		assert.Equal(t, io.EOF, err)
	})
}