From 59de2aeecb87d23e892c7589ae3b5d89e90850c8 Mon Sep 17 00:00:00 2001
From: Waldi Ravens <wr86420@gmail.com>
Date: Wed, 8 May 2019 09:00:03 +0200
Subject: [PATCH] Add FilePathComparer (Unix, Windows, Native)

---
 libse/FilePathComparer.cs | 69 +++++++++++++++++++++++++++++++++++++++
 libse/LibSE.csproj        |  1 +
 2 files changed, 70 insertions(+)
 create mode 100644 libse/FilePathComparer.cs

diff --git a/libse/FilePathComparer.cs b/libse/FilePathComparer.cs
new file mode 100644
index 000000000..e1c7f612f
--- /dev/null
+++ b/libse/FilePathComparer.cs
@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+namespace Nikse.SubtitleEdit.Core
+{
+    public abstract class FilePathComparer : IEqualityComparer<string>, IComparer<string>
+    {
+        private sealed class WindowsFilePathComparer: FilePathComparer
+        {
+            public override int Compare(string path1, string path2)
+            {
+                return ReferenceEquals(path1, path2)
+                     ? 0
+                     : ReferenceEquals(path2, null)
+                     ? 1
+                     : ReferenceEquals(path1, null)
+                     ? -1
+                     : string.Compare(path1.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar), path2.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar), StringComparison.OrdinalIgnoreCase);
+            }
+
+            public override bool Equals(string path1, string path2)
+            {
+                return ReferenceEquals(path1, path2) ||
+                       (!(ReferenceEquals(path1, null) || ReferenceEquals(path2, null)) &&
+                        string.Equals(path1.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar), path2.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar), StringComparison.OrdinalIgnoreCase));
+            }
+
+            public override int GetHashCode(string path)
+            {
+                return path.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar).ToUpperInvariant().GetHashCode();
+            }
+        }
+
+        private sealed class UnixFilePathComparer : FilePathComparer
+        {
+            public override int Compare(string path1, string path2)
+            {
+                return ReferenceEquals(path1, path2)
+                     ? 0
+                     : ReferenceEquals(path2, null)
+                     ? 1
+                     : ReferenceEquals(path1, null)
+                     ? -1
+                     : string.Compare(path1.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar), path2.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar), StringComparison.Ordinal);
+            }
+
+            public override bool Equals(string path1, string path2)
+            {
+                return ReferenceEquals(path1, path2) ||
+                       (!(ReferenceEquals(path1, null) || ReferenceEquals(path2, null)) &&
+                        string.Equals(path1.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar), path2.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar), StringComparison.Ordinal));
+            }
+
+            public override int GetHashCode(string path)
+            {
+                return path.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar).GetHashCode();
+            }
+        }
+
+        public static FilePathComparer Native => Configuration.IsRunningOnWindows ? Windows : Unix;
+        public static FilePathComparer Windows => new WindowsFilePathComparer();
+        public static FilePathComparer Unix => new UnixFilePathComparer();
+
+        public abstract int Compare(string path1, string path2);
+        public abstract bool Equals(string path1, string path2);
+        public abstract int GetHashCode(string path);
+    }
+}
diff --git a/libse/LibSE.csproj b/libse/LibSE.csproj
index 192ca2cc5..a9054bdb6 100644
--- a/libse/LibSE.csproj
+++ b/libse/LibSE.csproj
@@ -144,6 +144,7 @@
     <Compile Include="Enums\SubtitleSortCriteria.cs" />
     <Compile Include="FastBitmap.cs" />
     <Compile Include="FastFileStream.cs" />
+    <Compile Include="FilePathComparer.cs" />
     <Compile Include="FileUtil.cs" />
     <Compile Include="FixCasing.cs" />
     <Compile Include="Forms\CheckForUpdatesHelper.cs" />