From 2e8057aa54f4adc46ba23d3d52398b9a638d25b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C5=82awomir=20=C5=9Apiewak?=
 <sosw.slawomir.spiewak@gmail.com>
Date: Mon, 15 Jul 2024 14:15:14 +0200
Subject: [PATCH] Update ArcDX8.cs

Add anything that can be done without user input.
---
 ArcFormats/DxLib/ArcDX8.cs | 49 +++++++++++++++++++++++++++++++++-----
 1 file changed, 43 insertions(+), 6 deletions(-)

diff --git a/ArcFormats/DxLib/ArcDX8.cs b/ArcFormats/DxLib/ArcDX8.cs
index edc05b80..1a009819 100644
--- a/ArcFormats/DxLib/ArcDX8.cs
+++ b/ArcFormats/DxLib/ArcDX8.cs
@@ -41,27 +41,64 @@ namespace GameRes.Formats.DxLib
 
         public Dx8Opener ()
         {
-            Extensions = new[] { "bin" };
+            Extensions = new string[] { "dxa", "hud", "usi", "med", "dat", "bin", "bcx", "wolf" };
             Signatures = new[] { 0x00085844u };
         }
 
         static readonly byte[] DefaultKey = new byte[] { 0xBE, 0xC8, 0x8A, 0xF5, 0x28, 0x50, 0xC9 };
 
+
+        DxScheme DefaultScheme = new DxScheme { KnownKeys = new List<IDxKey>() };
+
+
+        internal struct DxHeaderV8
+        {
+            public long BaseOffset;
+            public long IndexOffset;
+            public uint IndexSize;
+            public long FileTable;
+            public long DirTable;
+            public int CodePage;
+            public DXA8Flags Flags;
+            public byte HuffmanKB;
+            //15 bytes of padding.
+        }
+
+        internal enum DXA8Flags : UInt32
+        {
+            DXA_FLAG_NO_KEY=1, //file is not encrypted
+            DXA_FLAG_NO_HEAD_PRESS=1<<1, //do not compress headers
+        }
+
         public override ArcFile TryOpen (ArcView file)
         {
-            var dx = new DxHeader {
+            var dx = new DxHeaderV8 {
                 IndexSize  = file.View.ReadUInt32 (4),
                 BaseOffset = file.View.ReadInt64 (8),
                 IndexOffset = file.View.ReadInt64 (0x10),
-                FileTable  = (uint)file.View.ReadInt64 (0x18),
-                DirTable   = (uint)file.View.ReadInt64 (0x20),
+                FileTable  = file.View.ReadInt64 (0x18),
+                DirTable   = file.View.ReadInt64 (0x20),
                 CodePage   = file.View.ReadInt32 (0x28),
+                Flags      = (DXA8Flags)file.View.ReadUInt32(0x2C),
+                HuffmanKB = file.View.ReadByte(0x30)
             };
             if (dx.DirTable >= dx.IndexSize || dx.FileTable >= dx.IndexSize)
                 return null;
+            //at this point we cannot proceed without user input. If NO_HEAD_PRESS is set we could maybe restore the 7-byte key
+            //Otherwise (assuming the archive is encrypted) we have no way to continue without user input.
+
+            //TODO: Ask for key here.
+          
             var key = DefaultKey;
-            var index = file.View.ReadBytes (dx.IndexOffset, dx.IndexSize);
-            Decrypt (index, 0, index.Length, 0, key);
+            if ((dx.Flags & DXA8Flags.DXA_FLAG_NO_HEAD_PRESS) != 0)
+            {
+                var index = file.View.ReadBytes(dx.IndexOffset, dx.IndexSize);
+                Decrypt(index, 0, index.Length, 0, key);
+            } else
+            {
+                //input is compressed. First by huffman then by LZ. if it's also encrypted then we're stuck.
+                throw new NotImplementedException();
+            }
             // decrypt-2
             // decompress
             return null;