using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
using UnityEngine.Networking;

public class MusicPlayer : MonoBehaviour
{
    private AudioSource audioSource;
    public string[] MusicFiles;         // 用於儲存 MP3 檔案的路徑
    public int currentTrackIndex = 0;   // 目前正在播放的音樂索引
    public bool isPaused = false;       // 控制是否暫停

    void Start()
    {
        audioSource = gameObject.GetComponent<AudioSource>();
        MusicFiles = Directory.GetFiles(@"C:\MyFiles", "*.mp3");

        if (MusicFiles.Length > 0)
        {
            StartCoroutine(PlayTrack(currentTrackIndex));  // 播放第一首音樂
        }
        else
        {
            Debug.LogError("資料夾沒有音樂檔案！");
        }
    }

    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            if (audioSource.isPlaying)
            {
                audioSource.Pause();   // 當按下空白鍵時，播放或暫停音樂
                isPaused = true;
            }
            else
            {
                if (isPaused)
                {
                    audioSource.UnPause();  // 如果是暫停狀態則繼續播放
                }
                else
                {
                    StartCoroutine(PlayTrack(currentTrackIndex));  // 播放當前音樂
                }
                isPaused = false;
            }
        }

        if (Input.GetKeyDown(KeyCode.UpArrow))
        {
            PlayPreviousTrack();   // 使用上鍵切換到上一首音樂
        }

        if (Input.GetKeyDown(KeyCode.DownArrow))
        {
            PlayNextTrack();       // 使用下鍵切換到下一首音樂
        }

        if (!audioSource.isPlaying && !isPaused)
        {
            PlayNextTrack();      // 當音樂播放完畢時，自動播放下一首
        }
    }

    IEnumerator PlayTrack(int index)
    {
        if (MusicFiles.Length > 0)
        {
            string url = "file:///" + MusicFiles[index];  // 建立檔案路徑 URL
            using (UnityWebRequest www = UnityWebRequestMultimedia.GetAudioClip(url, AudioType.MPEG))
            {
                yield return www.SendWebRequest();

                if (www.result == UnityWebRequest.Result.ConnectionError || www.result == UnityWebRequest.Result.ProtocolError)
                {
                    Debug.LogError("Error loading track: " + www.error);
                }
                else
                {
                    AudioClip clip = DownloadHandlerAudioClip.GetContent(www);
                    audioSource.clip = clip;
                    audioSource.Play();
                }
            }
        }
    }

    void PlayNextTrack()
    {
        currentTrackIndex = (currentTrackIndex + 1) % MusicFiles.Length;
        StartCoroutine(PlayTrack(currentTrackIndex));
    }

    void PlayPreviousTrack()
    {
        currentTrackIndex--;
        if (currentTrackIndex < 0)
        {
            currentTrackIndex = MusicFiles.Length - 1;
        }
        StartCoroutine(PlayTrack(currentTrackIndex));
    }
}