package http

import (
	"dwelling-radio/internal/radio"
	"dwelling-radio/pkg/oggtag"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"time"
)

var songList radio.SongList

type DJHandlers struct {
	listeners *radio.ListenerCounter
	playlist  *radio.Playlist
}

func NewDJHandlers(l *radio.ListenerCounter, p *radio.Playlist, slLen int) *DJHandlers {
	songList = *radio.NewSongList(slLen)
	return &DJHandlers{listeners: l, playlist: p}
}

func (dj *DJHandlers) ListenersGet(w http.ResponseWriter, _ *http.Request) {
	w.Header().Add("Content-Type", "text/plain")
	fmt.Fprint(w, dj.listeners.Current(), dj.listeners.Peak())
}

func (dj *DJHandlers) ListenersInc(w http.ResponseWriter, _ *http.Request) {
	l := dj.listeners.Inc()
	go func() {
		if l > songList.Current().MaxListeners {
			songList.Current().MaxListeners = l
		}
	}()
	w.WriteHeader(http.StatusCreated)
	w.Header().Add("Content-Type", "text/plain")
	fmt.Fprint(w, l)
}

func (dj *DJHandlers) ListenersDec(w http.ResponseWriter, _ *http.Request) {
	l, err := dj.listeners.Dec()
	if err != nil {
		log.Print(err)
		http.Error(w, err.Error(), http.StatusBadRequest)
	}
	w.WriteHeader(http.StatusOK)
	w.Header().Add("Content-Type", "text/plain")
	fmt.Fprint(w, l)
}

func (dj *DJHandlers) PlaylistNext(w http.ResponseWriter, _ *http.Request) {
	w.Header().Add("Content-Type", "text/plain")
	nxt := dj.playlist.Next()
	if nxt == "" {
		log.Println("the end of a playlist has been reached")
	} else {
		go func() {
			bs, be, err := oggtag.ReadFile(nxt)
			if err != nil {
				log.Println("cannot read an OGG file", nxt, ":", err)
			}

			song := radio.Song_{
				Artist:       oggtag.GetTag(bs, "artist"),
				Title:        oggtag.GetTag(bs, "title"),
				Duration:     oggtag.GetDuration(bs, be),
				MaxListeners: dj.listeners.Current(),
				StartAt:      time.Now()}
			// radio.CheckAndUpdateMostListenedSong(song, currentSong)
			songList.Add(song)
		}()
	}
	fmt.Fprint(w, nxt)
}

func (dj *DJHandlers) Song(w http.ResponseWriter, r *http.Request) {
	w.Header().Add("Content-Type", "application/json")
	err := json.NewEncoder(w).Encode(songList.Current())
	if err != nil {
		log.Println("DJHandlers.Song:", err)
		http.Error(w, "cannot obtain current song", http.StatusInternalServerError)
	}
}

func (dj *DJHandlers) Songs(w http.ResponseWriter, r *http.Request) {
	w.Header().Add("Content-Type", "application/json")
	err := json.NewEncoder(w).Encode(songList.List())
	if err != nil {
		log.Println("DJHandlers.Songs:", err)
		http.Error(w, "cannot obtain list of last songs", http.StatusInternalServerError)
	}
}

func (dj *DJHandlers) Status(w http.ResponseWriter, r *http.Request) {
	withList := r.URL.Query().Has("with-list")
	if withList {
		err := json.NewEncoder(w).Encode(&struct {
			Current   *radio.Song_           `json:"current_song,omitempty"`
			Listeners *radio.ListenerCounter `json:"listeners"`
			List      []radio.Song_          `json:"last_songs,omitempty"`
		}{
			Current:   songList.Current(),
			Listeners: dj.listeners,
			List:      songList.List()})
		if err != nil {
			log.Println("DJHandlers.Status-withList:", err)
		}
	}
}