package main

import (
	"context"

	"git.milar.in/milarin/anilist"
	"git.milar.in/milarin/channel"
	"git.milar.in/milarin/slices"
)

type Pair[A, B any] struct {
	First  A
	Second B
}

func GetAnimesToDownloadByAnimeID() (map[anilist.MediaID]*anilist.MediaList, error) {
	watchingAnimesChannel, err := GetCurrentlyWatchingAnimes()
	if err != nil {
		return nil, err
	}

	toMapFunc := func(entry *anilist.MediaList) (anilist.MediaID, *anilist.MediaList) { return entry.MediaID, entry }
	return channel.ToMap(watchingAnimesChannel, toMapFunc), nil
}

func GetCurrentlyWatchingAnimes() (<-chan *anilist.MediaList, error) {
	token, err := GetAnilistAccessToken()
	if err != nil {
		return nil, ErrAnimeListNotObtainable.Wrap(err, "access token acquisition failed")
	}

	media := slices.Map(AnimeStatus, func(status anilist.MediaListStatus) <-chan *anilist.MediaList {
		return anilist.NewApi(token).GetMediaList(context.Background(), anilist.MediaListQuery{
			UserName: AnilistUsername,
			Type:     anilist.MediaTypeAnime,
			Status:   status,
		}, nil).Chan
	})

	return channel.Merge(media...), nil
}

var (
	animeByTitleCache = map[string]Pair[*anilist.Media, error]{}
)

func SearchAnimeByTitle(title string) (anime *anilist.Media, err error) {
	// caching
	if cacheEntry, ok := animeByTitleCache[title]; ok {
		return cacheEntry.First, cacheEntry.Second
	}
	defer func() { animeByTitleCache[title] = Pair[*anilist.Media, error]{anime, err} }()

	token, err := GetAnilistAccessToken()
	if err != nil {
		return nil, err
	}

	anime = anilist.NewApi(token).GetMedia(context.Background(), anilist.MediaQuery{
		Search: title,
		Type:   anilist.MediaTypeAnime,
	}, nil).First()

	if anime == nil {
		return nil, ErrAnimeNotFound.New(title)
	}

	return anime, nil
}