using System;
using System.Runtime.InteropServices;

namespace MuHua {
	/// <summary>
	/// 适用于pc端的文件工具
	/// </summary>
	public static class FileTool {

#if UNITY_STANDALONE_WIN

		[DllImport("Comdlg32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
		public static extern bool GetOpenFileName([In, Out] FileDialog fileDialog);
		[DllImport("Shell32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
		private static extern IntPtr SHBrowseForFolder([In, Out] BrowseFolder browseFolder);
		[DllImport("Shell32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
		public static extern bool SHGetPathFromIDList([In] IntPtr dlist, [In] char[] path);
		[DllImport("Comdlg32.dll", CharSet = CharSet.Auto, SetLastError = true, ThrowOnUnmappableChar = true)]
		public static extern bool GetSaveFileName([In, Out] FileDialog fileDialog);

		/// <summary> 获取文件路径 </summary> 
		public static bool OpenFileType(string title, out string path, params string[] type) {
			return OpenFile(title, out path, FileTypes(type), type[0]);
		}
		/// <summary> 获取文件路径 </summary> 
		public static bool OpenFile(string title, out string path, string type, string expand) {
			FileDialog fd = new FileDialog();
			fd.structSize = Marshal.SizeOf(fd);
			fd.filter = type;
			fd.defExt = expand;
			fd.file = new string(new char[256]);
			fd.maxFile = fd.file.Length;
			fd.fileTitle = new string(new char[64]);
			fd.maxFileTitle = fd.fileTitle.Length;
			fd.initialDir = "C:/";
			fd.title = title;
			fd.flags = 0x00080000 | 0x00001000 | 0x00000800 | 0x00000200 | 0x00000008;
			return OpenFile(fd, out path);
		}
		/// <summary> 获取文件路径 </summary> 
		public static bool OpenFile(FileDialog fd, out string path) {
			bool result = GetOpenFileName(fd);
			path = fd.file;
			return result;
		}
		/// <summary> 获取保存路径 </summary> 
		public static bool SaveFileType(string title, out string path, params string[] type) {
			return SaveFile(title, out path, FileTypes(type), type[0]);
		}
		/// <summary> 获取保存路径 </summary> 
		public static bool SaveFile(string title, out string path, string type, string expand) {
			FileDialog fd = new FileDialog();
			fd.structSize = Marshal.SizeOf(fd);
			fd.filter = type;
			fd.defExt = expand;
			fd.file = new string(new char[256]);
			fd.maxFile = fd.file.Length;
			fd.fileTitle = new string(new char[64]);
			fd.maxFileTitle = fd.fileTitle.Length;
			fd.initialDir = "C:/";//默认路径
			fd.title = title;
			fd.flags = 0x00080000 | 0x00001000 | 0x00000800 | 0x00000200 | 0x00000008;
			return SaveFile(fd, out path);
		}
		/// <summary> 获取保存路径 </summary> 
		public static bool SaveFile(FileDialog fd, out string path) {
			bool result = GetSaveFileName(fd);
			path = fd.file;
			return result;
		}
		/// <summary> 获取文件夹路径 </summary> 
		public static string BrowseForFolder(string title = "Path") {
			BrowseFolder temp = new BrowseFolder();
			temp.pszDisplayName = new string(new char[2048]);
			temp.lpszTitle = title;
			temp.ulFlags = 0x00000040;
			IntPtr a = SHBrowseForFolder(temp);
			char[] path = new char[2048];
			for (int i = 0; i < 2048; i++) { path[i] = '\0'; }
			SHGetPathFromIDList(a, path);
			string res = new string(path);
			return res.Substring(0, res.IndexOf('\0'));
		}

#endif

		/// <summary> 文件类型 </summary> 
		public static string FileTypes(params string[] array) {
			string type = "";
			foreach (var item in array) { type += FileType(item); }
			return type;
		}
		/// <summary> 文件类型 </summary> 
		public static string FileType(string expand) {
			return $"(*.{expand})\0*.{expand}\0";//
		}

	}
	[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
	public class FileDialog {
		public int structSize = 0;
		public IntPtr dlgOwner = IntPtr.Zero;
		public IntPtr instance = IntPtr.Zero;
		public string filter = null;// 筛选文件类型
		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;// 默认路径
		public string title = null;// 窗口标题
		public int flags = 0;
		public short fileOffset = 0;
		public short fileExtension = 0;
		public string defExt = null;// 默认扩展名
		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;
	}
	[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
	public class BrowseFolder {
		public IntPtr hwndOwner = IntPtr.Zero;
		public IntPtr pidlRoot = IntPtr.Zero;
		public String pszDisplayName = null;
		public String lpszTitle = null;
		public UInt32 ulFlags = 0;
		public IntPtr lpfn = IntPtr.Zero;
		public IntPtr lParam = IntPtr.Zero;
		public int iImage = 0;
	}
}