using UnityEngine;

/// <summary>
/// 音频管理器：管理背景音乐和步骤语音解说。
/// 挂在场景 GameObject 上，通过 AudioSource 组件播放。
/// </summary>
[RequireComponent(typeof(AudioSource))]
public class AudioManager : MonoBehaviour
{
    public static AudioManager Instance { get; private set; }

    [Header("音频源")]
    [SerializeField] private AudioSource _bgmSource;
    [SerializeField] private AudioSource _voiceSource;

    [Header("背景音乐")]
    public AudioClip BGMClip;
    [Range(0f, 1f)] public float BGMVolume = 0.3f;

    private void Awake()
    {
        if (Instance != null) { Destroy(gameObject); return; }
        Instance = this;
        DontDestroyOnLoad(gameObject);

        if (_bgmSource == null) _bgmSource = GetComponent<AudioSource>();
        if (_voiceSource == null)
        {
            _voiceSource = gameObject.AddComponent<AudioSource>();
            _voiceSource.playOnAwake = false;
            _voiceSource.loop = false;
        }
    }

    private void Start()
    {
        PlayBGM();
    }

    public void PlayBGM()
    {
        if (_bgmSource == null || BGMClip == null) return;
        _bgmSource.clip = BGMClip;
        _bgmSource.volume = BGMVolume;
        _bgmSource.loop = true;
        _bgmSource.Play();
    }

    public void StopBGM()
    {
        if (_bgmSource != null) _bgmSource.Stop();
    }

    /// <summary>播放一步语音解说，自动打断前一条</summary>
    public void PlayVoice(AudioClip clip, float volume = 1f)
    {
        if (_voiceSource == null || clip == null) return;
        _voiceSource.Stop();
        _voiceSource.clip = clip;
        _voiceSource.volume = volume;
        _voiceSource.Play();
    }

    /// <summary>停止语音</summary>
    public void StopVoice()
    {
        if (_voiceSource != null) _voiceSource.Stop();
    }

    /// <summary>按文件名从 StreamingAssets 加载并播放语音</summary>
    public void PlayVoiceFromFile(string fileName)
    {
        if (string.IsNullOrEmpty(fileName)) return;
        StartCoroutine(LoadAndPlayVoice(fileName));
    }

    private System.Collections.IEnumerator LoadAndPlayVoice(string fileName)
    {
        string path = System.IO.Path.Combine(Application.streamingAssetsPath, "Voice", fileName);
        using var www = UnityEngine.Networking.UnityWebRequestMultimedia.GetAudioClip(path, AudioType.WAV);
        yield return www.SendWebRequest();
        if (www.result == UnityEngine.Networking.UnityWebRequest.Result.Success)
        {
            var clip = UnityEngine.Networking.DownloadHandlerAudioClip.GetContent(www);
            PlayVoice(clip);
        }
        else
        {
            Debug.LogWarning($"AudioManager: 加载语音失败 {path}");
        }
    }
}