Parse stash versions correctly

Author: ResurrectedTrader

src/D2SSharp.Tests/IntegrationTests.cs

@@ -263,13 +263,13 @@ public void RoundTrip_Stash_Saves(IExternalData externalData)
         var data = File.ReadAllBytes(Path.Combine("Resources", "99", "SharedStashSoftCoreV2.d2i"));
 
         // Read stash
-        var stash = D2StashSave.Read(data, externalData, saveVersion: 99);
+        var stash = D2StashSave.Read(data, externalData);
         Assert.NotEmpty(stash);
 
         // Write stash back
         var buffer = new byte[data.Length * 2];
         var writer = new BitWriter(buffer);
-        stash.Write(ref writer, externalData, saveVersion: 99);
+        stash.Write(ref writer, externalData);
         int written = writer.BytesWritten;
 
         // Compare

src/D2SSharp/Model/D2StashSave.cs

@@ -13,15 +13,14 @@ public partial class D2StashSave : List<D2StashTab>
     /// </summary>
     /// <param name="reader">The bit reader.</param>
     /// <param name="externalData">External game data for parsing items.</param>
-    /// <param name="saveVersion">Save file version (97+ for D2R format).</param>
     /// <returns>The parsed stash save containing all tabs.</returns>
-    public static D2StashSave Read(ref BitReader reader, IExternalData externalData, uint saveVersion)
+    public static D2StashSave Read(ref BitReader reader, IExternalData externalData)
     {
         var save = new D2StashSave();
 
         while (reader.BitsRemaining > D2StashTab.HeaderSize * 8)
         {
-            save.Add(D2StashTab.Read(ref reader, externalData, saveVersion));
+            save.Add(D2StashTab.Read(ref reader, externalData));
         }
 
         return save;
@@ -32,25 +31,24 @@ public static D2StashSave Read(ref BitReader reader, IExternalData externalData,
     /// </summary>
     /// <param name="data">The stash file data.</param>
     /// <param name="externalData">External game data for parsing items.</param>
-    /// <param name="saveVersion">Save file version (97+ for D2R format).</param>
     /// <returns>The parsed stash save containing all tabs.</returns>
-    public static D2StashSave Read(ReadOnlySpan<byte> data, IExternalData externalData, uint saveVersion)
+    public static D2StashSave Read(ReadOnlySpan<byte> data, IExternalData externalData)
     {
         var reader = new BitReader(data);
-        return Read(ref reader, externalData, saveVersion);
+        return Read(ref reader, externalData);
     }
 
     /// <summary>
     /// Writes all stash tabs to a BitWriter.
     /// </summary>
     /// <param name="writer">The bit writer.</param>
     /// <param name="externalData">External game data for writing items.</param>
-    /// <param name="saveVersion">Save file version (97+ for D2R format).</param>
-    public void Write(ref BitWriter writer, IExternalData externalData, uint saveVersion)
+    /// <param name="targetVersion">Optional target version for format conversion. If null, uses current Version.</param>
+    public void Write(ref BitWriter writer, IExternalData externalData, uint? targetVersion = null)
     {
         foreach (var tab in this)
         {
-            tab.Write(ref writer, externalData, saveVersion);
+            tab.Write(ref writer, externalData, targetVersion);
         }
     }
 }

src/D2SSharp/Model/D2StashTab.cs

@@ -1,4 +1,5 @@
 using D2SSharp.Data;
+using D2SSharp.Enums;
 using D2SSharp.IO;
 
 namespace D2SSharp.Model;
@@ -14,8 +15,11 @@ public partial class D2StashTab
     /// <summary>Tab magic value: 0xAA55AA55</summary>
     public const uint Magic = 0xAA55AA55;
 
-    /// <summary>Expected header value for D2R stash tabs.</summary>
-    public const ulong Header = 0x6300000001L;
+    /// <summary>Stash format.</summary>
+    public uint StashFormat { get; set; }
+
+    /// <summary>Item format in the stash.</summary>
+    public uint ItemFormat { get; set; }
 
     /// <summary>Gold amount stored in the stash tab.</summary>
     public uint Gold { get; set; }
@@ -34,9 +38,8 @@ public partial class D2StashTab
     /// </summary>
     /// <param name="reader">The bit reader.</param>
     /// <param name="externalData">External game data for parsing items.</param>
-    /// <param name="saveVersion">Save file version (97+ for D2R format).</param>
     /// <returns>The parsed stash tab.</returns>
-    public static D2StashTab Read(ref BitReader reader, IExternalData externalData, uint saveVersion)
+    public static D2StashTab Read(ref BitReader reader, IExternalData externalData)
     {
         var tab = new D2StashTab();
         int startPosition = reader.BytePosition;  // Record start
@@ -45,15 +48,13 @@ public static D2StashTab Read(ref BitReader reader, IExternalData externalData,
         if (magic != Magic)
             throw new InvalidDataException($"Invalid stash tab magic: 0x{magic:X8}, expected 0x{Magic:X8}");
 
-        ulong header = reader.ReadUInt64();
-        if (header != Header)
-            throw new InvalidDataException($"Invalid stash tab header: 0x{header:X16}, expected 0x{Header:X16}");
-
+        tab.StashFormat = reader.ReadUInt32();
+        tab.ItemFormat = reader.ReadUInt32();
         tab.Gold = reader.ReadUInt32();
         ushort size = reader.ReadUInt16(); // Size field (not stored, used for validation)
         tab.Season = reader.ReadUInt16();
         reader.ReadBytes(tab.Reserved);
-        tab.Items = ItemsSection.Read(ref reader, externalData, saveVersion);
+        tab.Items = ItemsSection.Read(ref reader, externalData, tab.ItemFormat);
 
         // Seek to the correct position for the next tab
         reader.SetBytePosition(startPosition + size);
@@ -66,13 +67,22 @@ public static D2StashTab Read(ref BitReader reader, IExternalData externalData,
     /// </summary>
     /// <param name="writer">The bit writer.</param>
     /// <param name="externalData">External game data for writing items.</param>
-    /// <param name="saveVersion">Save file version (97+ for D2R format).</param>
-    public void Write(ref BitWriter writer, IExternalData externalData, uint saveVersion)
+    /// <param name="targetVersion">Optional target version for format conversion. If null, uses current Version.</param>
+    public void Write(ref BitWriter writer, IExternalData externalData, uint? targetVersion = null)
     {
+        uint writeVersion = targetVersion ?? ItemFormat;
+
+        // Prepare for version conversion if needed (mutates data for new format)
+        PrepareForVersion(ItemFormat, writeVersion);
+
+        // Update Version permanently (data is now in the new format)
+        ItemFormat = writeVersion;
+
         int startPosition = writer.BytesWritten;
 
         writer.WriteUInt32(Magic);
-        writer.WriteUInt64(Header);
+        writer.WriteUInt32(StashFormat);
+        writer.WriteUInt32(ItemFormat);
         writer.WriteUInt32(Gold);
 
         // Write placeholder for size, will update at end
@@ -81,7 +91,7 @@ public void Write(ref BitWriter writer, IExternalData externalData, uint saveVer
         writer.WriteUInt16(Season);
         writer.WriteBytes(Reserved);
 
-        Items.Write(ref writer, externalData, saveVersion);
+        Items.Write(ref writer, externalData, writeVersion);
 
         // Calculate this tab's size and write it back
         int tabSize = writer.BytesWritten - startPosition;
@@ -90,4 +100,31 @@ public void Write(ref BitWriter writer, IExternalData externalData, uint saveVer
         writer.WriteUInt16((ushort)tabSize);
         writer.SetBitPosition(currentPosition);
     }
+
+    /// <summary>
+    /// Prepares the save data for writing to a specific version format.
+    /// Handles conversion between 1.14 (version 96) and D2R (version 97+) formats.
+    /// </summary>
+    private void PrepareForVersion(uint sourceVersion, uint targetVersion)
+    {
+        bool sourceIsD2R = sourceVersion > 96;
+        bool targetIsD2R = targetVersion > 96;
+
+        // Only convert if source and target formats differ
+        if (!sourceIsD2R && targetIsD2R)
+            Convert114ToD2R();
+    }
+
+    /// <summary>
+    /// Converts save data from 1.14 format to D2R format.
+    /// </summary>
+    private void Convert114ToD2R()
+    {
+        // 3. Zero BodyLocation for stored items (D2R fails otherwise)
+        foreach (var item in Items)
+        {
+            if (item.Position.Mode != ItemMode.Equipped)
+                item.Position.BodyLocation = BodyLocation.None;
+        }
+    }
 }