1 files changed, 68 insertions, 0 deletions
diff --git a/src/StardewModdingAPI/Framework/GameVersion.cs b/src/StardewModdingAPI/Framework/GameVersion.cs
new file mode 100644
index 00000000..48159f61
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/GameVersion.cs
@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+
+namespace StardewModdingAPI.Framework
+{
+    /// <summary>An implementation of <see cref="ISemanticVersion"/> that correctly handles the non-semantic versions used by older Stardew Valley releases.</summary>
+    internal class GameVersion : SemanticVersion
+    {
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>A mapping of game to semantic versions.</summary>
+        private static readonly IDictionary<string, string> VersionMap = new Dictionary<string, string>(StringComparer.InvariantCultureIgnoreCase)
+        {
+            ["1.01"] = "1.0.1",
+            ["1.02"] = "1.0.2",
+            ["1.03"] = "1.0.3",
+            ["1.04"] = "1.0.4",
+            ["1.05"] = "1.0.5",
+            ["1.051"] = "1.0.6-prerelease1", // not a very good mapping, but good enough for SMAPI's purposes.
+            ["1.051b"] = "1.0.6-prelease2",
+            ["1.06"] = "1.0.6",
+            ["1.07"] = "1.0.7",
+            ["1.07a"] = "1.0.8-prerelease1",
+            ["1.11"] = "1.1.1"
+        };
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="version">The game version string.</param>
+        public GameVersion(string version)
+            : base(GameVersion.GetSemanticVersionString(version)) { }
+
+        /// <summary>Get a string representation of the version.</summary>
+        public override string ToString()
+        {
+            return GameVersion.GetGameVersionString(base.ToString());
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Convert a game version string to a semantic version string.</summary>
+        /// <param name="gameVersion">The game version string.</param>
+        private static string GetSemanticVersionString(string gameVersion)
+        {
+            return GameVersion.VersionMap.TryGetValue(gameVersion, out string semanticVersion)
+                ? semanticVersion
+                : gameVersion;
+        }
+
+        /// <summary>Convert a game version string to a semantic version string.</summary>
+        /// <param name="gameVersion">The game version string.</param>
+        private static string GetGameVersionString(string gameVersion)
+        {
+            foreach (var mapping in GameVersion.VersionMap)
+            {
+                if (mapping.Value.Equals(gameVersion, StringComparison.InvariantCultureIgnoreCase))
+                    return mapping.Key;
+            }
+            return gameVersion;
+        }
+    }
+}