From b4f4042d3a2e32288491cf4ba3c3485f4f9f74c3 Mon Sep 17 00:00:00 2001
From: morkt <morkt@users.noreply.github.com>
Date: Thu, 9 Aug 2018 08:39:09 +0400
Subject: [PATCH] (Legacy): AR2 archives.

---
 Legacy/Kasane/ArcAR2.cs | 88 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 Legacy/Kasane/ArcAR2.cs

diff --git a/Legacy/Kasane/ArcAR2.cs b/Legacy/Kasane/ArcAR2.cs
new file mode 100644
index 00000000..b688c65e
--- /dev/null
+++ b/Legacy/Kasane/ArcAR2.cs
@@ -0,0 +1,88 @@
+//! \file       ArcAR2.cs
+//! \date       2018 Aug 06
+//! \brief      Script engine Kasane resource archive.
+//
+// Copyright (C) 2018 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+
+// [030525][Virgin Cream] Yamai Tsuki ~Ryouki Kansen Virus~
+
+namespace GameRes.Formats.Kasane
+{
+    [Export(typeof(ArchiveFormat))]
+    public class Ar2Opener : ArchiveFormat
+    {
+        public override string         Tag { get { return "AR2/IDX"; } }
+        public override string Description { get { return "Kasane script engine resource archive"; } }
+        public override uint     Signature { get { return 0; } }
+        public override bool  IsHierarchic { get { return false; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            if (!file.Name.HasExtension (".ar2"))
+                return null;
+            var idx_name = Path.ChangeExtension (file.Name, ".idx");
+            using (var idx_view = VFS.OpenView (idx_name))
+            using (var idx = idx_view.CreateStream())
+            {
+                int count = idx.ReadInt32();
+                if (!IsSaneCount (count))
+                    return null;
+                var name_buffer = new byte[0x100];
+                var dir = new List<Entry> (count);
+                for (int i = 0; i < count; ++i)
+                {
+                    uint size       = idx.ReadUInt32();
+                    uint unpacked_size = idx.ReadUInt32();
+                    idx.ReadInt32();
+                    int name_length = idx.ReadInt32();
+                    uint offset     = idx.ReadUInt32();
+                    if (name_length > name_buffer.Length)
+                        return null;
+                    idx.Read (name_buffer, 0, name_length);
+                    for (int j = 0; j < name_length; ++j)
+                        name_buffer[j] ^= 0x55;
+                    var name = Encodings.cp932.GetString (name_buffer, 0, name_length);
+                    var entry = FormatCatalog.Instance.Create<Entry> (name);
+                    entry.Offset = offset;
+                    entry.Size   = size;
+                    if (!entry.CheckPlacement (file.MaxOffset))
+                        return null;
+                    dir.Add (entry);
+                }
+                return new ArcFile (file, this, dir);
+            }
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            uint name_length = arc.File.View.ReadUInt32 (entry.Offset+0xC) ^ 0x55555555u;
+            var input = arc.File.CreateStream (entry.Offset + 0x10 + name_length, entry.Size);
+            return new XoredStream (input, 0x55);
+        }
+    }
+}