package main

import (
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"math/rand"
	"net/http"
	"os"
	"strconv"
)

var currentSong = -1
var games []GameData
var songQue []SongData

func getSoundCheckSong() string {
	reset()

	files, err := ioutil.ReadDir("songs")
	if err != nil {
		log.Fatal(err)
	}
	fileInfo := files[rand.Intn(len(files))]
	return "songs/" + fileInfo.Name()
}

func reset() {
	songQue = nil
	currentSong = -1
	games = findAllGames()
}

func getRandomSong() string {
	if games == nil || len(games) == 0 {
		games = findAllGames()
	}

	game := getRandomGame(games)

	songs := findSongsFromGame(game.id)

	song := songs[rand.Intn(len(songs))]

	currentSong = len(songQue)
	songQue = append(songQue, song)
	return song.path
}

func getRandomSongLowChance() string {
	gameList := findAllGames()

	var listOfGames []GameData

	var averagePlayed = getAveragePlayed(gameList)

	for _, data := range gameList {
		var timesToAdd = averagePlayed - data.timesPlayed
		if timesToAdd <= 0 {
			listOfGames = append(listOfGames, data)
		} else {
			for i := 0; i < timesToAdd; i++ {
				listOfGames = append(listOfGames, data)
			}
		}
	}

	game := getRandomGame(listOfGames)

	songs := findSongsFromGame(game.id)

	song := songs[rand.Intn(len(songs))]

	currentSong = len(songQue)
	songQue = append(songQue, song)
	return song.path

}

func getSongInfo() SongInfo {
	var currentSongData = songQue[currentSong]

	currentGameData := getCurrentGame(currentSongData)

	return SongInfo{
		Game:             currentGameData.gameName,
		GamePlayed:       currentGameData.timesPlayed,
		Song:             currentSongData.songName,
		SongPlayed:       currentSongData.timesPlayed,
		CurrentlyPlaying: true,
		SongNo:           currentSong,
	}
}

func getPlayedSongs() []SongInfo {
	var songList []SongInfo

	for i, song := range songQue {
		gameData := getCurrentGame(song)
		songList = append(songList, SongInfo{
			Game:             gameData.gameName,
			GamePlayed:       gameData.timesPlayed,
			Song:             song.songName,
			SongPlayed:       song.timesPlayed,
			CurrentlyPlaying: i == currentSong,
			SongNo:           i,
		})
	}
	return songList
}

func getSong(song string) string {
	currentSong, _ = strconv.Atoi(song)
	if currentSong >= len(songQue) {
		currentSong = len(songQue) - 1
	} else if currentSong < 0 {
		currentSong = 0
	}
	var songData = songQue[currentSong]
	return songData.path
}

func getAllGames() []string {
	if games == nil || len(games) == 0 {
		games = findAllGames()
	}

	var jsonArray []string
	for _, game := range games {
		jsonArray = append(jsonArray, game.gameName)
	}
	return jsonArray
}

func setPlayed(songNumber int) {
	if songQue == nil || len(songQue) == 0 || songNumber >= len(songQue) {
		return
	}
	var songData = songQue[songNumber]
	addGamePlayed(songData.gameId)
	addSongPlayed(songData.gameId, songData.songName)
}

func getNextSong() string {
	if currentSong == len(songQue)-1 || currentSong == -1 {
		return getRandomSong()
	} else {
		currentSong = currentSong + 1
		var songData = songQue[currentSong]
		return songData.path
	}
}

func getPreviousSong() string {
	if currentSong == -1 || currentSong == 0 {
		var songData = songQue[0]
		return songData.path
	} else {
		currentSong = currentSong - 1
		var songData = songQue[currentSong]
		return songData.path
	}
}

func musicHandler(w http.ResponseWriter, r *http.Request) {
	setCorsAndNoCacheHeaders(&w, r)
	if r.URL.Path == "/music" && r.Method == http.MethodGet {
		song := r.URL.Query().Get("song")
		if song == "" {
			w.WriteHeader(http.StatusBadRequest)
			_, err := fmt.Fprint(w, "song can't be empty")
			if err != nil {
				w.WriteHeader(http.StatusInternalServerError)
			}
		} else {
			s := getSong(song)
			sendFile(w, r, s)
			//http.ServeFile(w, r, s)
		}
	} else if r.URL.Path == "/music/first" && r.Method == http.MethodGet {
		song := getSoundCheckSong()
		sendFile(w, r, song)
		//http.ServeFile(w, r, getSoundCheckSong())

	} else if r.URL.Path == "/music/reset" && r.Method == http.MethodGet {
		reset()
		w.WriteHeader(http.StatusOK)

	} else if r.URL.Path == "/music/rand" && r.Method == http.MethodGet {
		song := getRandomSong()

		sendFile(w, r, song)

		/*file, _ := os.Open(song)
		seeker := io.ReadSeeker(file)
		http.ServeContent(w, r, song, time.Time{}, seeker)*/

	} else if r.URL.Path == "/music/rand/low" && r.Method == http.MethodGet {
		chance := getRandomSongLowChance()
		//http.ServeFile(w, r, chance)
		sendFile(w, r, chance)

	} else if r.URL.Path == "/music/info" && r.Method == http.MethodGet {
		w.Header().Add("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(getSongInfo())

	} else if r.URL.Path == "/music/list" && r.Method == http.MethodGet {
		w.Header().Add("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(getPlayedSongs())

	} else if r.URL.Path == "/music/next" {
		song := getNextSong()
		//http.ServeFile(w, r, song)
		sendFile(w, r, song)

	} else if r.URL.Path == "/music/previous" {
		song := getPreviousSong()
		//http.ServeFile(w, r, song)
		sendFile(w, r, song)

	} else if r.URL.Path == "/music/all" && r.Method == http.MethodGet {
		w.Header().Add("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(getAllGames())

	} else if r.URL.Path == "/music/played" && r.Method == http.MethodPut {
		var p Played
		err := json.NewDecoder(r.Body).Decode(&p)
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}
		setPlayed(p.song)
		w.WriteHeader(http.StatusOK)
	}
}

func sendFile(writer http.ResponseWriter, request *http.Request, Filename string) {
	fmt.Println("Client requests: " + Filename)

	//Check if file exists and open
	Openfile, err := os.Open(Filename)
	defer Openfile.Close() //Close after function return
	if err != nil {
		//File not found, send 404
		http.Error(writer, "File not found.", 404)
		return
	}

	//File is found, create and send the correct headers

	//Get the Content-Type of the file
	//Create a buffer to store the header of the file in
	FileHeader := make([]byte, 512)
	//Copy the headers into the FileHeader buffer
	_, _ = Openfile.Read(FileHeader)
	//Get content type of file
	//FileContentType := http.DetectContentType(FileHeader)

	//Get the file size
	FileStat, _ := Openfile.Stat()                     //Get info from file
	FileSize := strconv.FormatInt(FileStat.Size(), 10) //Get file size as a string

	//Send the headers
	writer.Header().Set("Content-Disposition", "attachment; filename="+Filename)
	writer.Header().Set("Content-Type", "audio/mpeg")
	writer.Header().Set("Content-Length", FileSize)

	//Send the file
	//We read 512 bytes from the file already, so we reset the offset back to 0
	_, _ = Openfile.Seek(0, 0)
	_, _ = io.Copy(writer, Openfile) //'Copy' the file to the client
	return
}

type Played struct {
	song int
}

func getCurrentGame(currentSongData SongData) GameData {
	for _, game := range games {
		if game.id == currentSongData.gameId {
			return game
		}
	}
	return GameData{}
}

func getAveragePlayed(gameList []GameData) int {
	var sum int
	for _, data := range gameList {
		sum += data.timesPlayed
	}
	return sum / len(gameList)
}

func getRandomGame(listOfGames []GameData) GameData {
	return listOfGames[rand.Intn(len(listOfGames))]
}