From 7899dbc7ce418a75311f03ec5c6a5cbd811f28c6 Mon Sep 17 00:00:00 2001
From: Michael Becker <alcexhim@gmail.com>
Date: Mon, 11 Apr 2022 19:14:24 -0400
Subject: [PATCH] properly implement Merscom DPK data format

---
 .../Associations/Merscom/DPK.uexml            | 25 +++++++++++
 .../FileSystem/Merscom/DPKDataFormat.cs       | 41 +++++++++++++------
 .../UniversalEditor.Plugins.FileSystem.csproj |  2 +
 3 files changed, 56 insertions(+), 12 deletions(-)
 create mode 100644 Plugins/UniversalEditor.Plugins.FileSystem/Associations/Merscom/DPK.uexml

diff --git a/Plugins/UniversalEditor.Plugins.FileSystem/Associations/Merscom/DPK.uexml b/Plugins/UniversalEditor.Plugins.FileSystem/Associations/Merscom/DPK.uexml
new file mode 100644
index 00000000..139a03da
--- /dev/null
+++ b/Plugins/UniversalEditor.Plugins.FileSystem/Associations/Merscom/DPK.uexml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<UniversalEditor Version="4.0">
+	<Associations>
+		<Association>
+			<Filters>
+				<Filter HintComparison="MagicThenFilter" ContentType="application/x-merscom-dpk" Title="Merscom data package (DPK) archive">
+					<FileNameFilters>
+						<FileNameFilter>*.dpk</FileNameFilter>
+					</FileNameFilters>
+					<MagicByteSequences>
+						<MagicByteSequence>
+							<MagicByte Type="String">DPK4</MagicByte>
+						</MagicByteSequence>
+					</MagicByteSequences>
+				</Filter>
+			</Filters>
+			<ObjectModels>
+				<ObjectModel TypeName="UniversalEditor.ObjectModels.FileSystem.FileSystemObjectModel" />
+			</ObjectModels>
+			<DataFormats>
+				<DataFormat TypeName="UniversalEditor.DataFormats.FileSystem.Merscom.DPKDataFormat" />
+			</DataFormats>
+		</Association>
+	</Associations>
+</UniversalEditor>
diff --git a/Plugins/UniversalEditor.Plugins.FileSystem/DataFormats/FileSystem/Merscom/DPKDataFormat.cs b/Plugins/UniversalEditor.Plugins.FileSystem/DataFormats/FileSystem/Merscom/DPKDataFormat.cs
index c8da3b13..b1f7fab8 100644
--- a/Plugins/UniversalEditor.Plugins.FileSystem/DataFormats/FileSystem/Merscom/DPKDataFormat.cs
+++ b/Plugins/UniversalEditor.Plugins.FileSystem/DataFormats/FileSystem/Merscom/DPKDataFormat.cs
@@ -28,6 +28,7 @@ namespace UniversalEditor.DataFormats.FileSystem.Merscom
 	/// <summary>
 	/// Provides a <see cref="DataFormat" />for manipulating archives in Merscom DPK format.
 	/// </summary>
+	[ImplementationStatus(DataFormatImplementationStatus.Load)]
 	public class DPKDataFormat : DataFormat
 	{
 		private static DataFormatReference _dfr;
@@ -53,27 +54,43 @@ namespace UniversalEditor.DataFormats.FileSystem.Merscom
 			if (DPK4 != "DPK4")
 				throw new InvalidDataFormatException();
 
-			uint u1 = br.ReadUInt32();
-			uint u2 = br.ReadUInt32();
+			uint archiveLength = br.ReadUInt32();
+			uint tocLength = br.ReadUInt32();
 			uint u3 = br.ReadUInt32();
-			uint u4 = br.ReadUInt32();
-			uint uFileCount = br.ReadUInt32();
-			for (int i = 0; i < uFileCount; i++)
+			for (int i = 0; i < u3; i++)
 			{
-				br.SeekUntilFirstNonNull();
+				uint u4 = br.ReadUInt32();
+				uint decompressedLength = br.ReadUInt32();
+				uint compressedLength = br.ReadUInt32();									// 371				39325
+				uint offset = br.ReadUInt32();									// 292196			292567
 
-				uint u6 = br.ReadUInt32();
-				uint u7 = br.ReadUInt32();
+				string nam = br.ReadNullTerminatedString();                 // action.accfg
+				br.Align(4);
 
-				string nam = br.ReadNullTerminatedString();
 				File file = fsom.AddFile(nam);
 
-				ushort u8 = br.ReadUInt16();
-				uint u9 = br.ReadUInt32();
-				uint u10 = br.ReadUInt32();
+				file.Properties["compressedLength"] = compressedLength;
+				file.Properties["offset"] = offset;
+
+				file.Size = decompressedLength;
+
+				file.DataRequest += File_DataRequest;
 			}
 		}
 
+		void File_DataRequest(object sender, DataRequestEventArgs e)
+		{
+			File file = (File)sender;
+			uint compressedLength = (uint)file.Properties["compressedLength"];
+			uint offset = (uint)file.Properties["offset"];
+
+			Accessor.Reader.Seek(offset, SeekOrigin.Begin);
+			byte[] compressedData = Accessor.Reader.ReadBytes(compressedLength);
+			byte[] decompressedData = Compression.CompressionModule.FromKnownCompressionMethod(Compression.CompressionMethod.Zlib).Decompress(compressedData);
+			e.Data = decompressedData;
+		}
+
+
 		protected override void SaveInternal(ObjectModel objectModel)
 		{
 			throw new NotImplementedException();
diff --git a/Plugins/UniversalEditor.Plugins.FileSystem/UniversalEditor.Plugins.FileSystem.csproj b/Plugins/UniversalEditor.Plugins.FileSystem/UniversalEditor.Plugins.FileSystem.csproj
index d35edc4a..59091cee 100644
--- a/Plugins/UniversalEditor.Plugins.FileSystem/UniversalEditor.Plugins.FileSystem.csproj
+++ b/Plugins/UniversalEditor.Plugins.FileSystem/UniversalEditor.Plugins.FileSystem.csproj
@@ -306,6 +306,7 @@
     <Folder Include="Associations\KenSilverman\" />
     <Folder Include="Associations\ElectronicArts\" />
     <Folder Include="Associations\Ultra3D\" />
+    <Folder Include="Associations\Merscom\" />
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="Associations\7Zip.uexml" />
@@ -396,6 +397,7 @@
     <EmbeddedResource Include="Associations\Ultra3D\RBX.uexml" />
     <EmbeddedResource Include="Associations\Ultra3D\TBV.uexml" />
     <EmbeddedResource Include="DataFormats\FileSystem\StuffIt\StuffItDataFormat.uexml" />
+    <EmbeddedResource Include="Associations\Merscom\DPK.uexml" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it.