using System;
using System.ComponentModel;
using System.IO;
using System.Runtime.InteropServices;
using UnityEngine;

public class FileDialogHelper
{
    public class FileOpMsg
    {
        public bool success;
        public string msg;
    }
    public const string IMAGEFILTER = "图片文件(*.jpg;*.png)\0*.jpg;*.png";
    public const string ALLFILTER = "所有文件(*.*)\0*.*";

    public bool CopySelectFile(string sourcePath, string targetPath)
    {
        try
        {
            File.Copy(sourcePath, targetPath + $"/{Path.GetFileName(sourcePath)}", true);
            return true;
        }
        catch (Exception)
        {
            Debug.LogError($"sourcePath = {sourcePath}");
            Debug.LogError($"targetPath = {Path.GetFileName(sourcePath)}");
            Debug.LogError("拷贝失败");
            return false;
        }
    }

    public string SelectFile(Action<FileOpMsg> callback, string filter = ALLFILTER)
    {
        Debug.Log("open 00");
        FileOpMsg fileOpMsg = new FileOpMsg();
        try
        {
            OpenFileName openFileName = new OpenFileName();
            openFileName.structSize = Marshal.SizeOf(openFileName);
            //openFileName.hwndOwner = WindowsTools.ProcessHandle;
            openFileName.filter = filter;
            openFileName.file = new string(new char[256]);
            openFileName.maxFile = openFileName.file.Length;
            openFileName.fileTitle = new string(new char[64]);
            openFileName.maxFileTitle = openFileName.fileTitle.Length;
            openFileName.title = "选择文件";
            openFileName.flags = 0x00080000 | 0x00001000 | 0x00000800 | 0x00000008;
            if (GetSaveFileName(openFileName))
            {
                string filepath = openFileName.file; //选择的文件路径;  
                if (File.Exists(filepath))
                {
                    fileOpMsg.success = true;
                    fileOpMsg.msg = filepath;
                    callback?.Invoke(fileOpMsg);
                    return fileOpMsg.msg;
                }
            }
        }
        catch (Exception e)
        {
            fileOpMsg.success = false;
            fileOpMsg.msg = e.ToString();
            callback?.Invoke(fileOpMsg);
            Debug.LogError(fileOpMsg.msg);
            return fileOpMsg.msg;
        }

        fileOpMsg.success = true;
        fileOpMsg.msg = string.Empty;
        callback?.Invoke(fileOpMsg);
        return fileOpMsg.msg;
    }

    [DllImport("Comdlg32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
    private static extern bool GetSaveFileName([In, Out] OpenFileName ofn);

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public class OpenFileName
    {
        public int structSize = 0;
        public IntPtr dlgOwner = IntPtr.Zero;
        public IntPtr instance = IntPtr.Zero;
        public String filter = null;
        public String customFilter = null;
        public int maxCustFilter = 0;
        public int filterIndex = 0;
        public String file = null;
        public int maxFile = 0;
        public String fileTitle = null;
        public int maxFileTitle = 0;
        public String initialDir = null;
        public String title = null;
        public int flags = 0;
        public short fileOffset = 0;
        public short fileExtension = 0;
        public String defExt = null;
        public IntPtr custData = IntPtr.Zero;
        public IntPtr hook = IntPtr.Zero;
        public String templateName = null;
        public IntPtr reservedPtr = IntPtr.Zero;
        public int reservedInt = 0;
        public int flagsEx = 0;
    }
    #region 隐藏
      

       /// <summary> 用于显示Windows平台的标准文件对话框 </summary>
       /// <param name="ofn"></param>
       /// <returns>返回用户所选文件的路径信息</returns>
       // 引入外部库，SetLastError = true将上一个错误代码设置为非零值，CharSet = CharSet.Auto字符集由运行时环境自动选择
       ///[In, Out]是修饰符，用于指定参数是既输入又输出的（类似于引用传参）
       [DllImport("Comdlg32.dll", SetLastError = true, CharSet = CharSet.Auto)]
       private static extern bool GetOpenFileName([In, Out] FileDialogWin ofn);


       [DllImport("kernel32.dll")]
       private static extern uint GetLastError();

       /// <summary>
       /// 打开文件对话框
       /// </summary>
       /// <param name="title">对话框标题</param>
       /// <param name="defaultPath">对话框默认路径</param>
       /// <param name="extension">文件默认格式</param>
       /// <returns></returns>
       public string OpenWindowsFileDialog(string title, string defaultPath, string extension)
       {

   #if UNITY_EDITOR

           return UnityEditor.EditorUtility.OpenFilePanel(title, defaultPath, extension);
   #else
       // 在运行时用原生对话框

           FileDialogWin ofn = new FileDialogWin();

           ofn.structSize = Marshal.SizeOf(ofn);
           ofn.filter = extension;
           ofn.file = new string(new char[256]);
           ofn.maxFile = ofn.file.Length;
           ofn.title = title;
           ofn.initialDir = defaultPath;
           ofn.flags = 0x00080000 | 0x00001000 | 0x00000800 | 0x00000008;

           bool result = GetOpenFileName(ofn);
           Debug.LogError($"ofn = {ofn}");
           Debug.LogError($"result: {result}");
           if (!result)
           {
               uint errorCode = GetLastError();
               Debug.LogError($"errorCode = {errorCode}");
               if (errorCode == 0)
                   {
                       // 用户取消了对话框，这是正常行为
                       Debug.Log("用户取消了文件选择");
                       return null;
                   }
                   else
               {
                   string errorMessage = new Win32Exception((int)errorCode).Message;
                   Debug.LogError($"打开文件对话框失败，错误代码: {errorCode}, 错误信息: {errorMessage}");

                   // 常见的错误代码
                   switch (errorCode)
                   {
                       case 0x00000002: // ERROR_FILE_NOT_FOUND
                           Debug.LogError("文件未找到，请检查默认路径是否存在");
                           break;
                       case 0x00000005: // ERROR_ACCESS_DENIED
                           Debug.LogError("访问被拒绝，可能没有足够的权限");
                           break;
                       case 0x00000057: // ERROR_INVALID_PARAMETER
                           Debug.LogError("参数无效，请检查结构体字段设置");
                           break;
                   }
               }
               return null;
           }
           return ofn.file;
   #endif
       }


       [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
       public class FileDialogWin
       {
           public int structSize = 0;
           public IntPtr dlgOwner = IntPtr.Zero;
           public IntPtr instance = IntPtr.Zero;

           public string filter = null;
           public string customFilter = null;
           public int maxCustFilter = 0;
           public int filterIndex = 0;

           public string file = null;
           public int maxFile = 0;

           public string initialDir = null;
           public string title = null;
           public int flags = 0;
           public short fileOffset = 0;
           public short fileExtension = 0;

           public string defExt = null;
           public IntPtr custData = IntPtr.Zero;
           public IntPtr hook = IntPtr.Zero;
           public string templateName = null;
           public IntPtr reservedPtr = IntPtr.Zero;
           public int reservedInt = 0;
           public int flagsEx = 0;
       }
   
    #endregion
}