package com.unity.filepicker;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.provider.OpenableColumns;
import android.util.Log;
import com.unity3d.player.UnityPlayer;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;

public class FilePicker {
    private static final String TAG = "[FILE-PICKER]";
    private static final int REQUEST_CODE_PICK_FILE = 1001;
    
    private static FilePickerCallback callback;
    
    public interface FilePickerCallback {
        void onFileSelected(String filePath, String fileName, byte[] fileData);
        void onFileSelectCanceled();
        void onError(String error);
    }
    
    /**
     * 打开文件选择器
     */
    public static void pickFile(String[] mimeTypes, FilePickerCallback cb) {
        Log.d(TAG, "[JAVA] pickFile() 被调用");
        callback = cb;
        
        try {
            Activity activity = UnityPlayer.currentActivity;
            if (activity == null) {
                Log.e(TAG, "[JAVA] UnityPlayer.currentActivity 为 null");
                if (callback != null) {
                    callback.onError("无法获取当前Activity");
                }
                return;
            }
            Log.d(TAG, "[JAVA] 获取到当前Activity: " + activity.getClass().getName());
            
            // 设置回调到 Activity
            setupActivityCallback(activity);
            
            Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
            intent.setType("*/*");
            
            // 设置可选的MIME类型
            if (mimeTypes != null && mimeTypes.length > 0) {
                intent.putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes);
                Log.d(TAG, "[JAVA] 设置MIME类型: " + java.util.Arrays.toString(mimeTypes));
            }
            
            intent.addCategory(Intent.CATEGORY_OPENABLE);
            
            // 创建选择器
            Intent chooser = Intent.createChooser(intent, "选择固件文件");
            Log.d(TAG, "[JAVA] 创建文件选择器Intent成功");
            
            // 启动文件选择器
            Log.d(TAG, "[JAVA] 启动文件选择器，requestCode=" + REQUEST_CODE_PICK_FILE);
            activity.startActivityForResult(chooser, REQUEST_CODE_PICK_FILE);
            Log.d(TAG, "[JAVA] startActivityForResult 调用成功");
            
        } catch (Exception e) {
            Log.e(TAG, "[JAVA] 打开文件选择器失败: " + e.getMessage());
            e.printStackTrace();
            if (callback != null) {
                callback.onError("打开文件选择器失败: " + e.getMessage());
            }
        }
    }
    
    /**
     * 设置Activity回调
     */
    private static void setupActivityCallback(Activity activity) {
        Log.d(TAG, "[JAVA] 设置Activity回调...");
        
        // 使用反射设置回调
        try {
            // 检查是否是 UnityActivityCallback 类型
            if (activity instanceof UnityActivityCallback) {
                Log.d(TAG, "[JAVA] Activity 是 UnityActivityCallback 类型");
                ((UnityActivityCallback) activity).setCallback(new UnityActivityCallback.FilePickerResultCallback() {
                    @Override
                    public void onActivityResult(int requestCode, int resultCode, Intent data) {
                        Log.d(TAG, "[JAVA] UnityActivityCallback.onActivityResult: requestCode=" + requestCode + ", resultCode=" + resultCode);
                        handleActivityResult(requestCode, resultCode, data);
                    }
                });
            } else {
                Log.w(TAG, "[JAVA] Activity 不是 UnityActivityCallback 类型，尝试使用反射");
                // 尝试使用反射设置静态回调
                UnityActivityCallback.setCallback(new UnityActivityCallback.FilePickerResultCallback() {
                    @Override
                    public void onActivityResult(int requestCode, int resultCode, Intent data) {
                        Log.d(TAG, "[JAVA] 通过反射回调: requestCode=" + requestCode + ", resultCode=" + resultCode);
                        handleActivityResult(requestCode, resultCode, data);
                    }
                });
            }
            Log.d(TAG, "[JAVA] Activity回调设置成功");
        } catch (Exception e) {
            Log.e(TAG, "[JAVA] 设置Activity回调失败: " + e.getMessage());
            e.printStackTrace();
        }
    }
    
    /**
     * 处理Activity结果 - 这个方法会被UnityActivityCallback调用
     */
    public static void handleActivityResult(int requestCode, int resultCode, Intent data) {
        Log.d(TAG, "[JAVA] handleActivityResult: requestCode=" + requestCode + ", resultCode=" + resultCode);
        
        if (requestCode != REQUEST_CODE_PICK_FILE) {
            Log.d(TAG, "[JAVA] requestCode不匹配，忽略");
            return;
        }
        
        if (resultCode != Activity.RESULT_OK || data == null) {
            Log.d(TAG, "[JAVA] 用户取消选择或data为null, resultCode=" + resultCode);
            if (callback != null) {
                callback.onFileSelectCanceled();
            }
            return;
        }
        
        // 在后台线程读取文件，避免阻塞主线程
        final Activity activity = UnityPlayer.currentActivity;
        final Uri uri = data.getData();
        
        if (uri == null) {
            Log.e(TAG, "[JAVA] 无法获取文件URI");
            if (callback != null) {
                callback.onError("无法获取文件URI");
            }
            return;
        }
        
        Log.d(TAG, "[JAVA] 文件URI: " + uri.toString());
        Log.d(TAG, "[JAVA] 在后台线程读取文件...");
        
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    // 获取文件名
                    Log.d(TAG, "[JAVA] 获取文件名...");
                    final String fileName = getFileName(activity, uri);
                    Log.d(TAG, "[JAVA] 文件名: " + fileName);
                    
                    // 读取文件数据
                    Log.d(TAG, "[JAVA] 读取文件数据...");
                    final byte[] fileData = readFileData(activity, uri);
                    Log.d(TAG, "[JAVA] 文件数据读取成功，大小: " + fileData.length);
                    
                    // 获取文件路径
                    final String filePath = uri.toString();
                    
                    Log.d(TAG, "[JAVA] 选择文件成功: " + fileName + ", 大小: " + fileData.length);
                    
                    // 在主线程回调
                    activity.runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            if (callback != null) {
                                Log.d(TAG, "[JAVA] 调用回调 onFileSelected");
                                callback.onFileSelected(filePath, fileName, fileData);
                            } else {
                                Log.e(TAG, "[JAVA] callback 为 null");
                            }
                        }
                    });
                    
                } catch (final Exception e) {
                    Log.e(TAG, "[JAVA] 读取文件失败: " + e.getMessage());
                    e.printStackTrace();
                    
                    activity.runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            if (callback != null) {
                                callback.onError("读取文件失败: " + e.getMessage());
                            }
                        }
                    });
                }
            }
        }).start();
    }
    
    /**
     * 获取文件名
     */
    private static String getFileName(Activity activity, Uri uri) {
        String result = null;
        
        if (uri.getScheme().equals("content")) {
            Log.d(TAG, "[JAVA] URI scheme is content, querying ContentResolver...");
            try (Cursor cursor = activity.getContentResolver().query(uri, null, null, null, null)) {
                if (cursor != null && cursor.moveToFirst()) {
                    int index = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
                    if (index >= 0) {
                        result = cursor.getString(index);
                        Log.d(TAG, "[JAVA] 从ContentResolver获取文件名: " + result);
                    }
                }
            } catch (Exception e) {
                Log.e(TAG, "[JAVA] 查询ContentResolver失败: " + e.getMessage());
            }
        }
        
        if (result == null) {
            result = uri.getLastPathSegment();
            Log.d(TAG, "[JAVA] 从URI path获取文件名: " + result);
        }
        
        return result != null ? result : "unknown";
    }
    
    /**
     * 读取文件数据
     */
    private static byte[] readFileData(Activity activity, Uri uri) throws Exception {
        Log.d(TAG, "[JAVA] 开始读取文件数据...");
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        
        try (InputStream inputStream = activity.getContentResolver().openInputStream(uri)) {
            if (inputStream == null) {
                throw new Exception("无法打开文件输入流");
            }
            
            byte[] buffer = new byte[4096];
            int bytesRead;
            int totalBytes = 0;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
                totalBytes += bytesRead;
            }
            Log.d(TAG, "[JAVA] 文件读取完成，总字节数: " + totalBytes);
        } catch (Exception e) {
            Log.e(TAG, "[JAVA] 读取文件时发生错误: " + e.getMessage());
            throw e;
        }
        
        return outputStream.toByteArray();
    }
}