package subsonic

import (
	"encoding/json"

	"git.noroutes.net/NoRoutes/vibetunes/internal/database"
)

func init() {
	registerExtension("indexBasedQueue", 1)
	register("getPlayQueueByIndex", handleGetPlayQueueByIndex)
	register("savePlayQueueByIndex", handleSavePlayQueueByIndex)
}

// The indexBasedQueue extension shares the same play_queues storage as
// the classic getPlayQueue/savePlayQueue (internal/subsonic/playqueue.go)
// — the table has always tracked the current *index*, not a song ID; the
// classic endpoints are the ones that lossily resolve index -> song ID
// for their "current" attribute. Duplicate song IDs in the queue are
// therefore already handled correctly by construction: saving stores a
// plain ordered ID list, and both current-track values (index here,
// looked-up ID for the classic endpoint) are derived from the same
// unambiguous index.
func handleGetPlayQueueByIndex(rc *Context) *apiError {
	db := rc.Server.DB
	q, err := database.GetPlayQueue(db, rc.User.ID)
	if err == database.ErrNotFound {
		rc.Response = newResponse()
		return nil
	}
	if err != nil {
		return newError(ErrGeneric, err.Error())
	}

	var ids []string
	if uerr := json.Unmarshal([]byte(q.SongIDsJSON), &ids); uerr != nil {
		return newError(ErrGeneric, "corrupt saved play queue")
	}

	out := &PlayQueueByIndex{
		CurrentIndex: q.CurrentIndex,
		Position:     int64(q.PositionMs),
		Username:     rc.User.Username,
		Changed:      isoTime(q.UpdatedAt),
		ChangedBy:    q.Client,
	}
	for _, id := range ids {
		song, serr := database.GetSong(db, id)
		if serr != nil {
			continue
		}
		mf, merr := database.GetMediaFile(db, song.MediaFileID)
		if merr != nil {
			continue
		}
		out.Entry = append(out.Entry, childFromSong(db, song, mf, albumOfSong(db, song), rc.User.ID))
	}

	rc.Response = newResponse()
	rc.Response.PlayQueueByIndex = out
	return nil
}

func handleSavePlayQueueByIndex(rc *Context) *apiError {
	ids := rc.Params.GetAll("id")
	position := rc.Params.Int("position", 0)
	client := rc.Params.Get("c")

	currentIndex := 0
	if len(ids) > 0 {
		var aerr *apiError
		currentIndex, aerr = rc.Params.RequiredInt("currentIndex")
		if aerr != nil {
			return aerr
		}
		if currentIndex < 0 || currentIndex >= len(ids) {
			return newError(ErrGeneric, "currentIndex out of range")
		}
	}

	encoded, err := json.Marshal(ids)
	if err != nil {
		return newError(ErrGeneric, err.Error())
	}
	if err := database.SavePlayQueue(rc.Server.DB, rc.User.ID, string(encoded), currentIndex, position, client); err != nil {
		return newError(ErrGeneric, err.Error())
	}
	rc.Response = newResponse()
	return nil
}