package http

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

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

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

func (dj *DJHandlers) ListenersGet(w http.ResponseWriter, _ *http.Request) {
	w.Header().Add("Content-Type", "application/json")
	json.NewEncoder(w).Encode(dj.listeners)
}

func (dj *DJHandlers) ListenersInc(w http.ResponseWriter, _ *http.Request) {
	l := dj.listeners.Inc()
	go dj.songList.UpdateCurrentMaxListeners(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)
		return
	}
	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() {
			oggf, err := oggtag.NewOggFile(nxt)
			if err != nil {
				log.Println("cannot read an OGG file", nxt, ":", err)
				http.Error(w, "cannot read an OGG file", http.StatusInternalServerError)
				return
			}

			song := radio.Song{
				Artist:       oggf.GetTag("artist"),
				Title:        oggf.GetTag("title"),
				Duration:     oggf.GetDuration(),
				MaxListeners: dj.listeners.Current(),
				StartAt:      time.Now()}
			radio.CheckAndUpdateMostListenedSong(dj.songList.Current())
			dj.songList.Add(song)
		}()
	}
	fmt.Fprintln(w, nxt)
}

func (dj *DJHandlers) Song(w http.ResponseWriter, r *http.Request) {
	w.Header().Add("Content-Type", "application/json")
	err := json.NewEncoder(w).Encode(dj.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(dj.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) {
	w.Header().Add("Content-Type", "application/json")
	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"`
		Mls       *radio.MostListenedSong `json:"most_listened_song,omitempty"`
	}{
		Current:   dj.songList.Current(),
		Listeners: dj.listeners,
		List:      dj.songList.List(),
		Mls:       radio.MostListened()})
	if err != nil {
		log.Println("DJHandlers.Status:", err)
		http.Error(w, "status parsing failed", http.StatusInternalServerError)
	}
}

func (dj *DJHandlers) MostListenedSong(w http.ResponseWriter, r *http.Request) {
	w.Header().Add("Content-Type", "application/json")
	mls := radio.MostListened()
	if mls == nil {
		w.WriteHeader(http.StatusNotFound)
		return
	}
	err := json.NewEncoder(w).Encode(mls)
	if err != nil {
		log.Println("DJHandlers.MostListenedSong:", err)
		http.Error(w, "MostListenedSong parsing failed", http.StatusInternalServerError)
	}
}