using System;
using UnityEngine;

/// <summary>
/// Android文件选择器 - 调用Android原生文件选择器
/// </summary>
public class AndroidFilePicker : MonoBehaviour
{
    public static AndroidFilePicker Instance { get; private set; }

    // 回调事件
    public event Action<string, string, byte[]> OnFileSelected;  // 文件路径, 文件名, 文件数据
    public event Action OnFileSelectCanceled;
    public event Action<string> OnError;

    private AndroidJavaClass _filePickerClass;

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

    private void OnDestroy()
    {
        if (Instance == this)
        {
            Instance = null;
        }
    }

    /// <summary>
    /// 打开文件选择器
    /// </summary>
    /// <param name="mimeTypes">可选的MIME类型过滤器，如 "application/octet-stream"</param>
    public void PickFile(string[] mimeTypes = null)
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        Debug.Log("[FILE-PICKER] [CS] PickFile() 被调用");
        try
        {
            if (_filePickerClass == null)
            {
                Debug.Log("[FILE-PICKER] [CS] 初始化 FilePicker Java类...");
                _filePickerClass = new AndroidJavaClass("com.unity.filepicker.FilePicker");
                Debug.Log("[FILE-PICKER] [CS] FilePicker Java类初始化成功");
            }

            // 创建回调代理
            Debug.Log("[FILE-PICKER] [CS] 创建回调代理...");
            FilePickerCallbackProxy callbackProxy = new FilePickerCallbackProxy(this);
            Debug.Log("[FILE-PICKER] [CS] 回调代理创建成功");

            // 调用Java方法
            Debug.Log("[FILE-PICKER] [CS] 调用Java方法 pickFile...");
            _filePickerClass.CallStatic("pickFile", mimeTypes, callbackProxy);

            Debug.Log("[FILE-PICKER] [CS] 打开文件选择器成功");
        }
        catch (Exception e)
        {
            Debug.LogError($"[FILE-PICKER] [CS] 打开文件选择器失败: {e.Message}\n{e.StackTrace}");
            OnError?.Invoke($"打开文件选择器失败: {e.Message}");
        }
#else
        Debug.LogWarning("[FILE-PICKER] [CS] 仅在Android平台可用");
        OnError?.Invoke("文件选择器仅在Android平台可用");
#endif
    }

    /// <summary>
    /// 从Unity接收文件选择结果
    /// </summary>
    public void OnFileSelectedFromJava(string filePath, string fileName, byte[] fileData)
    {
        Debug.Log($"[FILE-PICKER] [CS] 选择文件成功: {fileName}, 大小: {fileData?.Length ?? 0}");
        
        // 在主线程执行回调
        Loom.QueueOnMainThread(() =>
        {
            OnFileSelected?.Invoke(filePath, fileName, fileData);
        });
    }

    /// <summary>
    /// 从Unity接收取消事件
    /// </summary>
    public void OnFileSelectCanceledFromJava()
    {
        Debug.Log("[FILE-PICKER] [CS] 用户取消选择");
        
        Loom.QueueOnMainThread(() =>
        {
            OnFileSelectCanceled?.Invoke();
        });
    }

    /// <summary>
    /// 从Unity接收错误
    /// </summary>
    public void OnErrorFromJava(string error)
    {
        Debug.LogError($"[FILE-PICKER] [CS] 错误: {error}");
        
        Loom.QueueOnMainThread(() =>
        {
            OnError?.Invoke(error);
        });
    }
}

/// <summary>
/// 文件选择器回调代理 - 用于Java到C#的回调
/// </summary>
public class FilePickerCallbackProxy : AndroidJavaProxy
{
    private AndroidFilePicker _picker;

    public FilePickerCallbackProxy(AndroidFilePicker picker) : base("com.unity.filepicker.FilePicker$FilePickerCallback")
    {
        _picker = picker;
    }

    /// <summary>
    /// 文件选择成功回调
    /// </summary>
    public void onFileSelected(string filePath, string fileName, byte[] fileData)
    {
        _picker?.OnFileSelectedFromJava(filePath, fileName, fileData);
    }

    /// <summary>
    /// 用户取消回调
    /// </summary>
    public void onFileSelectCanceled()
    {
        _picker?.OnFileSelectCanceledFromJava();
    }

    /// <summary>
    /// 错误回调
    /// </summary>
    public void onError(string error)
    {
        _picker?.OnErrorFromJava(error);
    }
}