package youtube

import (
	"bytes"
	"context"
	"fmt"
	"log"
	"os"
	"path"
	"strings"
	"text/template"
	"time"

	"arimelody.space/live-vod-uploader/scanner"
	"golang.org/x/oauth2"
	"google.golang.org/api/option"
	"google.golang.org/api/youtube/v3"
)

var DEFAULT_TAGS = []string{
	"ari melody",
	"ari melody LIVE",
	"livestream",
	"vtuber",
	"twitch",
	"gaming",
	"let's play",
	"full VOD",
	"VOD",
	"stream",
	"archive",
}

const (
	CATEGORY_GAMING = "20"
	CATEGORY_ENTERTAINMENT = "24"
)

type TitleType int
const (
	TITLE_GAME TitleType = iota
	TITLE_OTHER
)

type (
	Title struct {
		Name string
		Type TitleType
		Url string
	}

	Video struct {
		Title *Title
		Part int
		Date time.Time
		Tags []string
		Filename string
	}
)

func BuildVideo(metadata *scanner.Metadata) (*Video, error) {
	var titleType TitleType
	switch metadata.Category.Type {
	case "gaming":
		titleType = TITLE_GAME
	default:
		titleType = TITLE_OTHER
	}

	videoDate, err := time.Parse("2006-01-02", metadata.Date)
	if err != nil {
		return nil, fmt.Errorf("failed to parse date from metadata: %v", err)
	}

	return &Video{
		Title: &Title{
			Name: metadata.Category.Name,
			Type: titleType,
			Url: metadata.Category.Url,
		},
		Part: metadata.Part,
		Date: videoDate,
		Tags: DEFAULT_TAGS,
		Filename: path.Join(
			metadata.FootageDir,
			fmt.Sprintf(
				"%s-fullvod.mkv",
				videoDate.Format("2006-01-02"),
			)),
	}, nil
}

type (
	MetaTitle struct {
		Name	string
		Type	string
		Url		string
	}

	Metadata struct {
		Date	string
		Title	*MetaTitle
		Part	int
	}
)

var titleTemplate *template.Template = template.Must(
	template.ParseFiles("template/title.txt"),
)
func BuildTitle(video *Video) (string, error) {
	var titleType string
	switch video.Title.Type {
	case TITLE_GAME:
		titleType = "game"
	case TITLE_OTHER:
		fallthrough
	default:
		titleType = "other"
	}

	out := &bytes.Buffer{}
	titleTemplate.Execute(out, Metadata{
		Date: strings.ToLower(video.Date.Format("02 Jan 2006")),
		Title: &MetaTitle{
			Name: video.Title.Name,
			Type: titleType,
			Url: video.Title.Url,
		},
		Part: video.Part,
	})

	return strings.TrimSpace(out.String()), nil
}

var descriptionTemplate *template.Template = template.Must(
	template.ParseFiles("template/description.txt"),
)
func BuildDescription(video *Video) (string, error) {
	var titleType string
	switch video.Title.Type {
	case TITLE_GAME:
		titleType = "game"
	case TITLE_OTHER:
		fallthrough
	default:
		titleType = "other"
	}

	out := &bytes.Buffer{}
	descriptionTemplate.Execute(out, Metadata{
		Date: strings.ToLower(video.Date.Format("02 Jan 2006")),
		Title: &MetaTitle{
			Name: video.Title.Name,
			Type: titleType,
			Url: video.Title.Url,
		},
		Part: video.Part,
	})

	return out.String(), nil
}

func UploadVideo(ctx context.Context, token *oauth2.Token, video *Video) (*youtube.Video, error) {
	title, err := BuildTitle(video)
	if err != nil {
		return nil, fmt.Errorf("failed to build title: %v", err)
	}
	description, err := BuildDescription(video)
	if err != nil {
		return nil, fmt.Errorf("failed to build description: %v", err)
	}

	service, err := youtube.NewService(
		ctx,
		option.WithScopes(youtube.YoutubeUploadScope),
		option.WithTokenSource(oauth2.StaticTokenSource(token)),
	)
	if err != nil {
		log.Fatalf("Failed to create youtube service: %v\n", err)
		return nil, err
	}

	videoService := youtube.NewVideosService(service)

	var categoryId string
	switch video.Title.Type {
	case TITLE_GAME:
		categoryId = CATEGORY_GAMING
	default:
		categoryId = CATEGORY_ENTERTAINMENT
	}

	call := videoService.Insert([]string{
		"snippet", "status",
	}, &youtube.Video{
		Snippet: &youtube.VideoSnippet{
			Title: title,
			Description: description,
			Tags: append(DEFAULT_TAGS, video.Tags...),
			CategoryId: categoryId, // gaming
		},
		Status: &youtube.VideoStatus{
			PrivacyStatus: "private",
		},
	}).NotifySubscribers(false)

	file, err := os.Open(video.Filename)
	if err != nil {
		log.Fatalf("Failed to open file: %v\n", err)
		return nil, err
	}
	call.Media(file)

	log.Println("Uploading video...")

	ytVideo, err := call.Do()
	if err != nil {
		log.Fatalf("Failed to upload video: %v\n", err)
		return nil, err
	}

	return ytVideo, err
}