From ef9fa562abdc49f43bfd6478e1af6de128c4cf69 Mon Sep 17 00:00:00 2001
From: Matt Nadareski <mnadareski@outlook.com>
Date: Tue, 30 Sep 2025 20:35:40 -0400
Subject: [PATCH] More BZip documenting

---
 .../Models/BZip2/Block.cs                     | 12 ++++++
 .../Models/BZip2/BlockHeader.cs               | 37 +++++++++++++++++++
 .../Models/BZip2/BlockTrees.cs                | 26 +++++++++++++
 .../Models/BZip2/Constants.cs                 |  2 +-
 4 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 SabreTools.Serialization/Models/BZip2/Block.cs
 create mode 100644 SabreTools.Serialization/Models/BZip2/BlockHeader.cs
 create mode 100644 SabreTools.Serialization/Models/BZip2/BlockTrees.cs

diff --git a/SabreTools.Serialization/Models/BZip2/Block.cs b/SabreTools.Serialization/Models/BZip2/Block.cs
new file mode 100644
index 00000000..d527576e
--- /dev/null
+++ b/SabreTools.Serialization/Models/BZip2/Block.cs
@@ -0,0 +1,12 @@
+namespace SabreTools.Data.Models.BZip2
+{
+    public class Block
+    {
+        /// <summary>
+        /// Block header
+        /// </summary>
+        public BlockHeader? Header { get; set; }
+
+        // TODO: Implement remaining structures
+    }
+}
diff --git a/SabreTools.Serialization/Models/BZip2/BlockHeader.cs b/SabreTools.Serialization/Models/BZip2/BlockHeader.cs
new file mode 100644
index 00000000..04a41087
--- /dev/null
+++ b/SabreTools.Serialization/Models/BZip2/BlockHeader.cs
@@ -0,0 +1,37 @@
+namespace SabreTools.Data.Models.BZip2
+{
+    public class BlockHeader
+    {
+        /// <summary>
+        /// A 48-bit integer value 31 41 59 26 53 59, which
+        /// is the binary-coded decimal representation of
+        /// pi. It is used to differentiate the block
+        /// from the footer.
+        /// </summary>
+        /// <remarks>This may not be byte-aligned</remarks>
+        public byte[]? Magic { get; set; }
+
+        /// <summary>
+        /// The CRC-32 checksum of the uncompressed data contained
+        /// in <see cref="BlockData"/>. It is the same checksum
+        /// used in GZip, but is slightly different due to the
+        /// bit-packing differences.
+        /// </summary>
+        public uint Crc32 { get; set; }
+
+        /// <summary>
+        /// Should be 0. Previous versions of BZip2 allowed
+        /// the input data to be randomized to avoid
+        /// pathological strings from causing the runtime
+        /// to be exponential.
+        /// </summary>
+        /// <remarks>Actually a 1-bit value</remarks>
+        public byte Randomized { get; set; }
+
+        /// <summary>
+        /// Contains the origin pointer used in the BWT stage
+        /// </summary>
+        /// <remarks>Actually a 24-bit value</remarks>
+        public uint OrigPtr { get; set; }
+    }
+}
diff --git a/SabreTools.Serialization/Models/BZip2/BlockTrees.cs b/SabreTools.Serialization/Models/BZip2/BlockTrees.cs
new file mode 100644
index 00000000..9d735a06
--- /dev/null
+++ b/SabreTools.Serialization/Models/BZip2/BlockTrees.cs
@@ -0,0 +1,26 @@
+namespace SabreTools.Data.Models.BZip2
+{
+    public class BlockTrees
+    {
+        // TODO: Implement SymMap
+
+        /// <summary>
+        /// Indicates the number of Huffman trees used in
+        /// the HUFF stage. It must between 2 and 6.
+        /// </summary>
+        /// <remarks>Actually a 3-bit value</remarks>
+        public byte NumTrees { get; set; }
+
+        /// <summary>
+        /// Indicates the number of selectors used in the
+        /// HUFF stage. There must be at least 1 selector
+        /// defined.
+        /// </summary>
+        /// <remarks>Actually a 15-bit value</remarks>
+        public ushort NumSels { get; set; }
+
+        // TODO: Implement Selectors
+
+        // TODO: Implement Trees
+    }
+}
\ No newline at end of file
diff --git a/SabreTools.Serialization/Models/BZip2/Constants.cs b/SabreTools.Serialization/Models/BZip2/Constants.cs
index 298d8fd1..ed505c82 100644
--- a/SabreTools.Serialization/Models/BZip2/Constants.cs
+++ b/SabreTools.Serialization/Models/BZip2/Constants.cs
@@ -6,4 +6,4 @@ namespace SabreTools.Data.Models.BZip2
 
         public const string SignatureString = "BZh";
     }
-}
\ No newline at end of file
+}