package regio43

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"time"
)

type YoutubeChannel struct {
	Id   string
	Name string
}

type PlaylistItem struct {
	Etag         string
	Id           string
	PublishedAt  time.Time
	Channel      YoutubeChannel
	VideoId      string
	Title        string
	Description  string
	ThumbnailUrl string
	Position     int
}

type PlaylistResponseSnippet struct {
	PublishedAt            string                     `json:"publishedAt"`
	VideoOwnerChannelId    string                     `json:"videoOwnerChannelId"`
	VideoOwnerChannelTitle string                     `json:"videoOwnerChannelTitle"`
	ResourceId             PlaylistResponseResourceId `json:"resourceId"`
	Title                  string                     `json:"title"`
	Description            string                     `json:"description"`
	Position               int                        `json:"position"`
}

type PlaylistResponseItem struct {
	Etag    string                  `json:"etag"`
	Id      string                  `json:"id"`
	Snippet PlaylistResponseSnippet `json:"snippet"`
}

type PlaylistResponseResourceId struct {
	VideoId string `json:"videoId"`
}

type PlaylistResponse struct {
	Items         []PlaylistResponseItem `json:"items"`
	NextPageToken string                 `json:"nextPageToken"`
}

func requestYouTubePlaylist(playlistId string, pageToken string) ([]PlaylistItem, string) {
	apiUrl, err := url.Parse("https://www.googleapis.com/youtube/v3/playlistItems")
	if err != nil {
		panic(err)
	}

	q := apiUrl.Query()
	q.Add("key", os.Getenv("GOOGLE_API_KEY"))
	q.Add("playlistId", playlistId)
	q.Add("part", "id,snippet,contentDetails,status")
	q.Add("maxResults", "50")

	if pageToken != "" {
		q.Add("pageToken", pageToken)
	}

	apiUrl.RawQuery = q.Encode()

	response, err := http.Get(apiUrl.String())
	if err != nil {
		return nil, ""
	}

	body, err := io.ReadAll(response.Body)
	if err != nil {
		return nil, ""
	}

	//type playlistResponse PlaylistResponse
	var playlistItems PlaylistResponse
	err = json.Unmarshal(body, &playlistItems)
	if err != nil {
		return nil, ""
	}

	var items []PlaylistItem
	for _, item := range playlistItems.Items {
		publishedAt, err := time.Parse(time.RFC3339, item.Snippet.PublishedAt)
		if err != nil {
			panic(err)
		}

		items = append(items, PlaylistItem{
			Etag:         item.Etag,
			Id:           item.Id,
			PublishedAt:  publishedAt,
			VideoId:      item.Snippet.ResourceId.VideoId,
			Title:        item.Snippet.Title,
			Description:  item.Snippet.Description,
			ThumbnailUrl: fmt.Sprint("https://youtubethumbnails.prettysunflower.moe/", item.Snippet.ResourceId.VideoId),
			Position:     item.Snippet.Position,
			Channel: YoutubeChannel{
				Id:   item.Snippet.VideoOwnerChannelId,
				Name: item.Snippet.VideoOwnerChannelTitle,
			},
		})
	}

	return items, playlistItems.NextPageToken
}

func getPlaylistOfVideos(playlistId string) []PlaylistItem {
	var playlistItems []PlaylistItem
	nextPageToken := ""

	for {
		newItems, newNextPageToken := requestYouTubePlaylist(playlistId, nextPageToken)
		playlistItems = append(playlistItems, newItems...)

		if newNextPageToken == "" {
			return playlistItems
		}

		nextPageToken = newNextPageToken
	}
}