using System;
using System.IO;

namespace PDFPatcher.Common
{
	static class FileHelper
	{
		enum OverwriteType
		{
			Prompt, Overwrite, Skip
		}
		static OverwriteType __OverwriteMode;

		public static bool HasExtension(FilePath fileName, string extension) {
			return fileName.HasExtension(extension);
		}
		public static bool HasFileNameMacro(string fileName) {
			var c = '<';
			foreach (var item in fileName) {
				if (item == c) {
					if (c == '>') {
						return true;
					}
					c = '>';
				}
			}
			return false;
		}
		public static int NumericAwareComparePath(string path1, string path2) {
			const char PathDot = '.';
			var l1 = path1?.Length ?? 0;
			var l2 = path2?.Length ?? 0;
			if (l1 == 0 || l2 == 0) {
				return l1 - l2;
			}
			int n1 = 0, n2 = 0;
			for (int i1 = 0, i2 = 0; i1 < l1 && i2 < l2; i1++, i2++) {
				var x = path1[i1];
				var y = path2[i2];
				if (x < '0' || x > '9') {
					// 不区分大小写的文字比较
					if (x != y) {
						x = ToLowerAscii(x);
						y = ToLowerAscii(y);
						if (x == y) {
							continue;
						}
						return x == PathDot ? -1
							: y == PathDot ? 1
							: y < '0' || y > '9' ? LocaleInfo.StringComparer(x.ToString(), y.ToString(), System.Globalization.CompareOptions.StringSort)
							// path2 为数字，path1 不为数字，path2 排在前面
							: 1;
					}
				}
				else if (IsPathSeparator(x)) {
					if (IsPathSeparator(y)) {
						continue;
					}
					return -1;
				}
				else if (IsPathSeparator(y)) {
					return 1;
				}
				else {
					// 数字比较
					if (y >= '0' && y <= '9') {
						// 两组均为数字
						do {
							if (x > '0' || n1 > 0) {
								++n1;
							}
						} while (++i1 < l1 && (x = path1[i1]) >= '0' && x <= '9');
						do {
							if (y > '0' || n2 > 0) {
								++n2;
							}
						} while (++i2 < l2 && (y = path2[i2]) >= '0' && y <= '9');
						// 数字位数少的在前面
						if (n1 != n2) {
							return n1 - n2;
						}
						// 全是 0，继续后面的比较
						if (n1 == 0 || n2 == 0) {
							--i1;
							--i2;
							continue;
						}
						i1 -= n1;
						i2 -= n2;
						for (int i = 0; i < n1; i++, i1++, i2++) {
							x = path1[i1];
							y = path2[i2];
							if (x != y) {
								return x - y;
							}
						}
						// 数值相等，比较下一组
						n1 = n2 = 0;
						--i1;
						--i2;
					}
					else {
						// 仅 x 为数字，y 不为数字
						return y == PathDot ? 1 : x - y;
					}
				}
			}
			return path1.Length - path2.Length;
		}
		static char ToLowerAscii(char c) {
			return c >= 'A' && c <= 'Z' ? (char)(c + ('a' - 'A')) : c;
		}

		internal static bool CheckOverwrite(string targetFile) {
			if (!File.Exists(targetFile)) {
				return true;
			}

			switch (__OverwriteMode) {
				case OverwriteType.Prompt:
					var r = Common.FormHelper.YesNoCancelBox(String.Join("\n", new string[] {
						"是否覆盖目标文件？", targetFile, "\n按住 Shift 键重复此对话框的选择，本次操作不再弹出覆盖文件提示。"
					}));
					if (r == System.Windows.Forms.DialogResult.No) {
						if (FormHelper.IsShiftKeyDown) {
							__OverwriteMode = OverwriteType.Skip;
						}
						goto case OverwriteType.Skip;
					}
					else if (r == System.Windows.Forms.DialogResult.Cancel) {
						throw new OperationCanceledException();
					}
					if (FormHelper.IsShiftKeyDown) {
						__OverwriteMode = OverwriteType.Overwrite;
					}
					break;
				case OverwriteType.Overwrite:
					return true;
				case OverwriteType.Skip:
					Tracker.TraceMessage(Tracker.Category.ImportantMessage, "取消覆盖文件：" + targetFile);
					return false;
				default:
					goto case OverwriteType.Prompt;
			}

			return true;
		}

		public static string CombinePath(string path1, string path2) {
			if (string.IsNullOrEmpty(path2)) {
				return path1 ?? string.Empty;
			}
			if (string.IsNullOrEmpty(path1)) {
				return path2;
			}
			var l2 = path2.Length;
			if (l2 > 0) {
				if (IsPathSeparator(path2[0]) || (l2 > 1 && path2[1] == Path.VolumeSeparatorChar)) {
					return path2;
				}
			}
			var ch = path1[path1.Length - 1];
			if (IsPathSeparator(ch) == false) {
				return path1 + Path.DirectorySeparatorChar + path2;
			}
			return path1 + path2;
		}
		public static bool ComparePath(FilePath path1, FilePath path2) {
			return path1.Equals(path2);
		}

		public static bool IsPathValid(string filePath) {
			return String.IsNullOrEmpty(filePath) == false && filePath.Trim().Length > 0
				&& filePath.IndexOfAny(FilePath.InvalidPathChars) == -1;
		}
		static bool IsPathSeparator(char c) {
			return c == Path.DirectorySeparatorChar || c == Path.AltDirectorySeparatorChar;
		}

		internal static void ResetOverwriteMode() {
			__OverwriteMode = OverwriteType.Prompt;
		}

		internal static string MakePathRootedAndWithExtension(string path, string basePath, string extName, bool forceExt) {
			var p = Path.Combine(Path.GetDirectoryName(basePath), path);
			return Path.GetExtension(p).Length == 0 || forceExt ? (string)new FilePath(p).EnsureExtension(extName) : p;
		}

		static FilePath AttachExtensionName(FilePath fileName, string extension) {
			return fileName.EnsureExtension(extension);
		}

		static string GetNewFileName(string fileName, string extName) {
			var tmpName = AttachExtensionName(fileName, extName);
			var n = 1;
			while (tmpName.ExistsFile) {
				tmpName = AttachExtensionName(fileName + "[" + (++n) + "]", extName);
			}
			return tmpName.ToString();
		}
		public static string GetValidFileName(FilePath fileName) {
			return fileName.SubstituteInvalidChars('_').ToString();
		}
		internal static string GetNewFileNameFromSourceFile(string fileName, string extName) {
			var d = Path.GetDirectoryName(fileName);
			return GetNewFileName(
				d + @"\" + Path.GetFileNameWithoutExtension(fileName),
				extName)
				.Replace(@"\\", @"\");
		}
		internal static string GetTempNameFromFileDirectory(string fileName, string extName) {
			var f = Path.GetDirectoryName(fileName);
			var t = Path.GetTempFileName();
			return Path.Combine(f, t + extName);
		}
		public static string GetEllipticPath(string path, int length) {
			if (length < 11) {
				length = 11;
			}
			return path == null ? string.Empty
				: path.Length > length ? (path.Substring(0, 7) + "..." + path.Substring(path.Length - (length - 10)))
				: path;
		}

		public static byte[] DumpBytes(this byte[] source, FilePath path) {
			return source.DumpBytes(path, 0, source?.Length ?? 0);
		}
		public static byte[] DumpBytes(this byte[] source, FilePath path, int offset, int count) {
			using (var f = new FileStream(path.ToFullPath(), FileMode.OpenOrCreate, FileAccess.Write)) {
				if (source == null) {
					return null;
				}
				f.Write(source, offset, count);
			}
			return source;
		}
		public static byte[] DumpHexBinBytes(this byte[] source, FilePath path) {
			using (var f = new StreamWriter(path.ToFullPath())) {
				if (source == null) {
					return null;
				}
				byte t;
				for (int i = 0; i < source.Length; i++) {
					if (i > 0) {
						if ((i & 0xF) == 0) {
							f.WriteLine();
						}
						if ((i & 0x1) == 0) {
							f.Write(' ');
						}
					}
					var b = source[i];
					t = (byte)(b >> 4);
					f.Write((char)(t + (t > 9 ? ('A' - 10) : 0x30)));
					t = (byte)(b & 0x0F);
					f.Write((char)(t + (t > 9 ? ('A' - 10) : 0x30)));
				}
			}
			return source;
		}

		static class LocaleInfo
		{
			public static readonly Func<string, string, System.Globalization.CompareOptions, int> StringComparer = System.Globalization.CultureInfo.CurrentCulture.CompareInfo.Compare;
		}
	}
}