From ac285c48fe88fba474e8c9f06662421e8a14097d Mon Sep 17 00:00:00 2001
From: Matt Nadareski <mnadareski@outlook.com>
Date: Tue, 30 Sep 2025 20:25:18 -0400
Subject: [PATCH] Start documenting BZip in code

---
 .../Models/BZip2/Archive.cs                   | 14 +++++++---
 .../Models/BZip2/Footer.cs                    | 27 +++++++++++++++++++
 .../Models/BZip2/Header.cs                    | 25 +++++++++++++++++
 3 files changed, 63 insertions(+), 3 deletions(-)
 create mode 100644 SabreTools.Serialization/Models/BZip2/Footer.cs
 create mode 100644 SabreTools.Serialization/Models/BZip2/Header.cs

diff --git a/SabreTools.Serialization/Models/BZip2/Archive.cs b/SabreTools.Serialization/Models/BZip2/Archive.cs
index 3678a4df..ffacc92f 100644
--- a/SabreTools.Serialization/Models/BZip2/Archive.cs
+++ b/SabreTools.Serialization/Models/BZip2/Archive.cs
@@ -1,10 +1,18 @@
 namespace SabreTools.Data.Models.BZip2
 {
-    /// <summary>
-    /// This is a placeholder model for future work
-    /// </summary>
+    /// <see href="https://github.com/dsnet/compress/blob/master/doc/bzip2-format.pdf"/>
     public class Archive
     {
+        /// <summary>
+        /// Stream header
+        /// </summary>
+        public Header? Header { get; set; }
 
+        // TODO: Implement remaining structures
+
+        /// <summary>
+        /// Stream footer
+        /// </summary>
+        public Footer? Footer { get; set; }
     }
 }
diff --git a/SabreTools.Serialization/Models/BZip2/Footer.cs b/SabreTools.Serialization/Models/BZip2/Footer.cs
new file mode 100644
index 00000000..0bfdcee2
--- /dev/null
+++ b/SabreTools.Serialization/Models/BZip2/Footer.cs
@@ -0,0 +1,27 @@
+namespace SabreTools.Data.Models.BZip2
+{
+    public class Footer
+    {
+        /// <summary>
+        /// A 48-bit integer value 17 72 45 38 50 90, which
+        /// is the binary-coded decimal representation of
+        /// sqrt(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>
+        /// Contains a custom checksum computed using each of
+        /// the Block CRCs.
+        /// </summary>
+        /// <remarks>This may not be byte-aligned</remarks>
+        public uint Checksum { get; set; }
+
+        /// <summary>
+        /// Used to align the bit-stream to the next byte-aligned
+        /// edge and will contain between 0 and 7 bits.
+        /// </summary>
+        public byte Padding { get; set; }
+    }
+}
diff --git a/SabreTools.Serialization/Models/BZip2/Header.cs b/SabreTools.Serialization/Models/BZip2/Header.cs
new file mode 100644
index 00000000..49b27941
--- /dev/null
+++ b/SabreTools.Serialization/Models/BZip2/Header.cs
@@ -0,0 +1,25 @@
+namespace SabreTools.Data.Models.BZip2
+{
+    public class Header
+    {
+        /// <summary>
+        /// "BZ"
+        /// </summary>
+        public string? Signature { get; set; }
+
+        /// <summary>
+        /// Version byte
+        /// </summary>
+        /// <remarks>
+        /// '0' indicates a BZ1 file
+        /// 'h' indicates a BZ2 file
+        /// </remarks>
+        public byte Version { get; set; }
+
+        /// <summary>
+        /// ASCII value of the compression level
+        /// </summary>
+        /// <remarks>Valid values between '1' and '9'</remarks>
+        public byte Level { get; set; }
+    }
+}