From eaabd2ee7704bfcb59b3c67626c92747cd753f17 Mon Sep 17 00:00:00 2001
From: Matt Nadareski <mnadareski@outlook.com>
Date: Wed, 5 Nov 2025 09:37:56 -0500
Subject: [PATCH] Add static readers for CD-ROM sector types

---
 .../Models/CDROM/Mode1.cs                     |  2 +-
 .../Models/CDROM/Mode2Form1.cs                |  2 +-
 SabreTools.Serialization/Readers/CDROM.cs     | 97 +++++++++++++++++++
 3 files changed, 99 insertions(+), 2 deletions(-)
 create mode 100644 SabreTools.Serialization/Readers/CDROM.cs

diff --git a/SabreTools.Serialization/Models/CDROM/Mode1.cs b/SabreTools.Serialization/Models/CDROM/Mode1.cs
index b34d24d7..6ab9cf3b 100644
--- a/SabreTools.Serialization/Models/CDROM/Mode1.cs
+++ b/SabreTools.Serialization/Models/CDROM/Mode1.cs
@@ -22,7 +22,7 @@ namespace SabreTools.Data.Models.CDROM
         public byte[] Intermediate { get; set; } = new byte[8];
 
         /// <summary>
-        /// Error Correction Code, 4 bytes
+        /// Error Correction Code, 276 bytes
         /// </summary>
         public byte[] ECC { get; set; } = new byte[276];
     }
diff --git a/SabreTools.Serialization/Models/CDROM/Mode2Form1.cs b/SabreTools.Serialization/Models/CDROM/Mode2Form1.cs
index 417fa1e7..3ad4fa36 100644
--- a/SabreTools.Serialization/Models/CDROM/Mode2Form1.cs
+++ b/SabreTools.Serialization/Models/CDROM/Mode2Form1.cs
@@ -22,7 +22,7 @@ namespace SabreTools.Data.Models.CDROM
         public byte[] EDC { get; set; } = new byte[4];
 
         /// <summary>
-        /// Error Correction Code, 4 bytes
+        /// Error Correction Code, 276 bytes
         /// </summary>
         public byte[] ECC { get; set; } = new byte[276];
     }
diff --git a/SabreTools.Serialization/Readers/CDROM.cs b/SabreTools.Serialization/Readers/CDROM.cs
new file mode 100644
index 00000000..2026d35e
--- /dev/null
+++ b/SabreTools.Serialization/Readers/CDROM.cs
@@ -0,0 +1,97 @@
+using System.IO;
+using SabreTools.Data.Extensions;
+using SabreTools.Data.Models.CDROM;
+using SabreTools.IO.Extensions;
+
+namespace SabreTools.Serialization.Readers
+{
+    /// <summary>
+    /// This intentionally does not inherit from <see cref="BaseBinaryReader"/>
+    /// </summary>
+    public class CDROM
+    {
+        /// <summary>
+        /// Parse a Stream into a DataSector
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled DataSector on success, null on error</returns>
+        /// <remarks>Assumes a seekable stream</remarks>
+        public static DataSector? ParseDataSector(Stream data)
+        {
+            SectorMode sectorMode = data.GetSectorMode();
+            return sectorMode switch
+            {
+                SectorMode.MODE0 => null, // TODO: Create data sector for Mode0
+                SectorMode.MODE1 => ParseMode1(data),
+                SectorMode.MODE2 => null, // TODO: Create a data sector for Mode2 formless
+                SectorMode.MODE2_FORM1 => ParseMode2Form1(data),
+                SectorMode.MODE2_FORM2 => ParseMode2Form2(data),
+
+                SectorMode.UNKNOWN => null,
+                _ => null,
+            };
+        }
+
+        /// <summary>
+        /// Parse a Stream into a Mode1
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled Mode1 on success, null on error</returns>
+        public static Mode1 ParseMode1(Stream data)
+        {
+            var obj = new Mode1();
+
+            obj.SyncPattern = data.ReadBytes(12);
+            obj.Address = data.ReadBytes(3);
+            obj.Mode = data.ReadByteValue();
+
+            obj.UserData = data.ReadBytes(2048);
+            obj.EDC = data.ReadBytes(4);
+            obj.Intermediate = data.ReadBytes(8);
+            obj.ECC = data.ReadBytes(276);
+
+            return obj;
+        }
+
+        /// <summary>
+        /// Parse a Stream into a Mode2Form1
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled Mode2Form1 on success, null on error</returns>
+        public static Mode2Form1 ParseMode2Form1(Stream data)
+        {
+            var obj = new Mode2Form1();
+
+            obj.SyncPattern = data.ReadBytes(12);
+            obj.Address = data.ReadBytes(3);
+            obj.Mode = data.ReadByteValue();
+
+            obj.Subheader = data.ReadBytes(8);
+            obj.UserData = data.ReadBytes(2048);
+            obj.EDC = data.ReadBytes(4);
+            obj.ECC = data.ReadBytes(276);
+
+            return obj;
+        }
+
+        /// <summary>
+        /// Parse a Stream into a Mode2Form2
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled Mode2Form2 on success, null on error</returns>
+        public static Mode2Form2 ParseMode2Form2(Stream data)
+        {
+            var obj = new Mode2Form2();
+
+            obj.SyncPattern = data.ReadBytes(12);
+            obj.Address = data.ReadBytes(3);
+            obj.Mode = data.ReadByteValue();
+
+            obj.Subheader = data.ReadBytes(8);
+            obj.UserData = data.ReadBytes(2324);
+            obj.EDC = data.ReadBytes(4);
+
+            return obj;
+        }
+    }
+}