Merge branch 'develop' into stable

17 files changed, 624 insertions, 141 deletions

diff --git a/src/StardewModdingAPI/Framework/Exceptions/SAssemblyLoadFailedException.cs b/src/StardewModdingAPI/Framework/Exceptions/SAssemblyLoadFailedException.cs
new file mode 100644
index 00000000..ec9279f1
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/Exceptions/SAssemblyLoadFailedException.cs
@@ -0,0 +1,16 @@
+using System;
+
+namespace StardewModdingAPI.Framework.Exceptions
+{
+    /// <summary>An exception thrown when an assembly can't be loaded by SMAPI, with all the relevant details in the message.</summary>
+    internal class SAssemblyLoadFailedException : Exception
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="message">The error message.</param>
+        public SAssemblyLoadFailedException(string message)
+            : base(message) { }
+    }
+}
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;
+        }
+    }
+}
diff --git a/src/StardewModdingAPI/Framework/ModHelpers/ContentHelper.cs b/src/StardewModdingAPI/Framework/ModHelpers/ContentHelper.cs
index 5f72176e..ffa78ff6 100644
--- a/src/StardewModdingAPI/Framework/ModHelpers/ContentHelper.cs
+++ b/src/StardewModdingAPI/Framework/ModHelpers/ContentHelper.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics.CodeAnalysis;
@@ -33,10 +33,19 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <summary>The friendly mod name for use in errors.</summary>
         private readonly string ModName;
 
+        /// <summary>Encapsulates monitoring and logging for a given module.</summary>
+        private readonly IMonitor Monitor;
+
 
         /*********
         ** Accessors
         *********/
+        /// <summary>The game's current locale code (like <c>pt-BR</c>).</summary>
+        public string CurrentLocale => this.ContentManager.GetLocale();
+
+        /// <summary>The game's current locale as an enum value.</summary>
+        public LocalizedContentManager.LanguageCode CurrentLocaleConstant => this.ContentManager.GetCurrentLanguage();
+
         /// <summary>The observable implementation of <see cref="AssetEditors"/>.</summary>
         internal ObservableCollection<IAssetEditor> ObservableAssetEditors { get; } = new ObservableCollection<IAssetEditor>();
 
@@ -44,10 +53,10 @@ namespace StardewModdingAPI.Framework.ModHelpers
         internal ObservableCollection<IAssetLoader> ObservableAssetLoaders { get; } = new ObservableCollection<IAssetLoader>();
 
         /// <summary>Interceptors which provide the initial versions of matching content assets.</summary>
-        internal IList<IAssetLoader> AssetLoaders => this.ObservableAssetLoaders;
+        public IList<IAssetLoader> AssetLoaders => this.ObservableAssetLoaders;
 
         /// <summary>Interceptors which edit matching content assets after they're loaded.</summary>
-        internal IList<IAssetEditor> AssetEditors => this.ObservableAssetEditors;
+        public IList<IAssetEditor> AssetEditors => this.ObservableAssetEditors;
 
 
         /*********
@@ -58,13 +67,15 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="modFolderPath">The absolute path to the mod folder.</param>
         /// <param name="modID">The unique ID of the relevant mod.</param>
         /// <param name="modName">The friendly mod name for use in errors.</param>
-        public ContentHelper(SContentManager contentManager, string modFolderPath, string modID, string modName)
+        /// <param name="monitor">Encapsulates monitoring and logging.</param>
+        public ContentHelper(SContentManager contentManager, string modFolderPath, string modID, string modName, IMonitor monitor)
             : base(modID)
         {
             this.ContentManager = contentManager;
             this.ModFolderPath = modFolderPath;
             this.ModName = modName;
             this.ModFolderPathFromContent = this.GetRelativePath(contentManager.FullRootDirectory, modFolderPath);
+            this.Monitor = monitor;
         }
 
         /// <summary>Load content from the game folder or mod folder (if not already cached), and return it. When loading a <c>.png</c> file, this must be called outside the game's draw loop.</summary>
@@ -176,6 +187,25 @@ namespace StardewModdingAPI.Framework.ModHelpers
             }
         }
 
+        /// <summary>Remove an asset from the content cache so it's reloaded on the next request. This will reload core game assets if needed, but references to the former asset will still show the previous content.</summary>
+        /// <param name="key">The asset key to invalidate in the content folder.</param>
+        /// <exception cref="ArgumentException">The <paramref name="key"/> is empty or contains invalid characters.</exception>
+        /// <returns>Returns whether the given asset key was cached.</returns>
+        public bool InvalidateCache(string key)
+        {
+            this.Monitor.Log($"Requested cache invalidation for '{key}'.", LogLevel.Trace);
+            string actualKey = this.GetActualAssetKey(key, ContentSource.GameContent);
+            return this.ContentManager.InvalidateCache((otherKey, type) => otherKey.Equals(actualKey, StringComparison.InvariantCultureIgnoreCase));
+        }
+
+        /// <summary>Remove all assets of the given type from the cache so they're reloaded on the next request. <b>This can be a very expensive operation and should only be used in very specific cases.</b> This will reload core game assets if needed, but references to the former assets will still show the previous content.</summary>
+        /// <typeparam name="T">The asset type to remove from the cache.</typeparam>
+        /// <returns>Returns whether any assets were invalidated.</returns>
+        public bool InvalidateCache<T>()
+        {
+            this.Monitor.Log($"Requested cache invalidation for all assets of type {typeof(T)}. This is an expensive operation and should be avoided if possible.", LogLevel.Trace);
+            return this.ContentManager.InvalidateCache((key, type) => typeof(T).IsAssignableFrom(type));
+        }
 
         /*********
         ** Private methods
diff --git a/src/StardewModdingAPI/Framework/ModHelpers/ReflectionHelper.cs b/src/StardewModdingAPI/Framework/ModHelpers/ReflectionHelper.cs
index 9411a97a..14a339da 100644
--- a/src/StardewModdingAPI/Framework/ModHelpers/ReflectionHelper.cs
+++ b/src/StardewModdingAPI/Framework/ModHelpers/ReflectionHelper.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using StardewModdingAPI.Framework.Reflection;
 
 namespace StardewModdingAPI.Framework.ModHelpers
@@ -13,16 +13,21 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <summary>The underlying reflection helper.</summary>
         private readonly Reflector Reflector;
 
+        /// <summary>The mod name for error messages.</summary>
+        private readonly string ModName;
+
 
         /*********
         ** Public methods
         *********/
         /// <summary>Construct an instance.</summary>
         /// <param name="modID">The unique ID of the relevant mod.</param>
+        /// <param name="modName">The mod name for error messages.</param>
         /// <param name="reflector">The underlying reflection helper.</param>
-        public ReflectionHelper(string modID, Reflector reflector)
+        public ReflectionHelper(string modID, string modName, Reflector reflector)
             : base(modID)
         {
+            this.ModName = modName;
             this.Reflector = reflector;
         }
 
@@ -37,6 +42,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <returns>Returns the field wrapper, or <c>null</c> if the field doesn't exist and <paramref name="required"/> is <c>false</c>.</returns>
         public IPrivateField<TValue> GetPrivateField<TValue>(object obj, string name, bool required = true)
         {
+            this.AssertAccessAllowed(obj);
             return this.Reflector.GetPrivateField<TValue>(obj, name, required);
         }
 
@@ -47,6 +53,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
         public IPrivateField<TValue> GetPrivateField<TValue>(Type type, string name, bool required = true)
         {
+            this.AssertAccessAllowed(type);
             return this.Reflector.GetPrivateField<TValue>(type, name, required);
         }
 
@@ -60,6 +67,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="required">Whether to throw an exception if the private property is not found.</param>
         public IPrivateProperty<TValue> GetPrivateProperty<TValue>(object obj, string name, bool required = true)
         {
+            this.AssertAccessAllowed(obj);
             return this.Reflector.GetPrivateProperty<TValue>(obj, name, required);
         }
 
@@ -70,6 +78,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="required">Whether to throw an exception if the private property is not found.</param>
         public IPrivateProperty<TValue> GetPrivateProperty<TValue>(Type type, string name, bool required = true)
         {
+            this.AssertAccessAllowed(type);
             return this.Reflector.GetPrivateProperty<TValue>(type, name, required);
         }
 
@@ -89,6 +98,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// </remarks>
         public TValue GetPrivateValue<TValue>(object obj, string name, bool required = true)
         {
+            this.AssertAccessAllowed(obj);
             IPrivateField<TValue> field = this.GetPrivateField<TValue>(obj, name, required);
             return field != null
                 ? field.GetValue()
@@ -107,6 +117,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// </remarks>
         public TValue GetPrivateValue<TValue>(Type type, string name, bool required = true)
         {
+            this.AssertAccessAllowed(type);
             IPrivateField<TValue> field = this.GetPrivateField<TValue>(type, name, required);
             return field != null
                 ? field.GetValue()
@@ -122,6 +133,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
         public IPrivateMethod GetPrivateMethod(object obj, string name, bool required = true)
         {
+            this.AssertAccessAllowed(obj);
             return this.Reflector.GetPrivateMethod(obj, name, required);
         }
 
@@ -131,6 +143,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
         public IPrivateMethod GetPrivateMethod(Type type, string name, bool required = true)
         {
+            this.AssertAccessAllowed(type);
             return this.Reflector.GetPrivateMethod(type, name, required);
         }
 
@@ -144,6 +157,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
         public IPrivateMethod GetPrivateMethod(object obj, string name, Type[] argumentTypes, bool required = true)
         {
+            this.AssertAccessAllowed(obj);
             return this.Reflector.GetPrivateMethod(obj, name, argumentTypes, required);
         }
 
@@ -154,7 +168,35 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
         public IPrivateMethod GetPrivateMethod(Type type, string name, Type[] argumentTypes, bool required = true)
         {
+            this.AssertAccessAllowed(type);
             return this.Reflector.GetPrivateMethod(type, name, argumentTypes, required);
         }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Assert that mods can use the reflection helper to access the given type.</summary>
+        /// <param name="type">The type being accessed.</param>
+        private void AssertAccessAllowed(Type type)
+        {
+#if !SMAPI_1_x
+            // validate type namespace
+            if (type.Namespace != null)
+            {
+                string rootSmapiNamespace = typeof(Program).Namespace;
+                if (type.Namespace == rootSmapiNamespace || type.Namespace.StartsWith(rootSmapiNamespace + "."))
+                    throw new InvalidOperationException($"SMAPI blocked access by {this.ModName} to its internals through the reflection API. Accessing the SMAPI internals is strongly discouraged since they're subject to change, which means the mod can break without warning.");
+            }
+#endif
+        }
+
+        /// <summary>Assert that mods can use the reflection helper to access the given type.</summary>
+        /// <param name="obj">The object being accessed.</param>
+        private void AssertAccessAllowed(object obj)
+        {
+            if (obj != null)
+                this.AssertAccessAllowed(obj.GetType());
+        }
     }
 }
diff --git a/src/StardewModdingAPI/Framework/ModLoading/AssemblyLoadStatus.cs b/src/StardewModdingAPI/Framework/ModLoading/AssemblyLoadStatus.cs
new file mode 100644
index 00000000..11be19fc
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/ModLoading/AssemblyLoadStatus.cs
@@ -0,0 +1,15 @@
+namespace StardewModdingAPI.Framework.ModLoading
+{
+    /// <summary>Indicates the result of an assembly load.</summary>
+    internal enum AssemblyLoadStatus
+    {
+        /// <summary>The assembly was loaded successfully.</summary>
+        Okay = 1,
+
+        /// <summary>The assembly could not be loaded.</summary>
+        Failed = 2,
+
+        /// <summary>The assembly is already loaded.</summary>
+        AlreadyLoaded = 3
+    }
+}
diff --git a/src/StardewModdingAPI/Framework/ModLoading/AssemblyLoader.cs b/src/StardewModdingAPI/Framework/ModLoading/AssemblyLoader.cs
index 406d49e1..b14ae56f 100644
--- a/src/StardewModdingAPI/Framework/ModLoading/AssemblyLoader.cs
+++ b/src/StardewModdingAPI/Framework/ModLoading/AssemblyLoader.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -6,6 +6,7 @@ using System.Reflection;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using StardewModdingAPI.AssemblyRewriters;
+using StardewModdingAPI.Framework.Exceptions;
 
 namespace StardewModdingAPI.Framework.ModLoading
 {
@@ -65,16 +66,27 @@ namespace StardewModdingAPI.Framework.ModLoading
                 AssemblyDefinitionResolver resolver = new AssemblyDefinitionResolver();
                 HashSet<string> visitedAssemblyNames = new HashSet<string>(AppDomain.CurrentDomain.GetAssemblies().Select(p => p.GetName().Name)); // don't try loading assemblies that are already loaded
                 assemblies = this.GetReferencedLocalAssemblies(new FileInfo(assemblyPath), visitedAssemblyNames, resolver).ToArray();
-                if (!assemblies.Any())
-                    throw new InvalidOperationException($"Could not load '{assemblyPath}' because it doesn't exist.");
-                resolver.Add(assemblies.Select(p => p.Definition).ToArray());
             }
 
+            // validate load
+            if (!assemblies.Any() || assemblies[0].Status == AssemblyLoadStatus.Failed)
+            {
+                throw new SAssemblyLoadFailedException(!File.Exists(assemblyPath)
+                    ? $"Could not load '{assemblyPath}' because it doesn't exist."
+                    : $"Could not load '{assemblyPath}'."
+                );
+            }
+            if (assemblies[0].Status == AssemblyLoadStatus.AlreadyLoaded)
+                throw new SAssemblyLoadFailedException($"Could not load '{assemblyPath}' because it was already loaded. Do you have two copies of this mod?");
+
             // rewrite & load assemblies in leaf-to-root order
             bool oneAssembly = assemblies.Length == 1;
             Assembly lastAssembly = null;
             foreach (AssemblyParseResult assembly in assemblies)
             {
+                if (assembly.Status == AssemblyLoadStatus.AlreadyLoaded)
+                    continue;
+
                 bool changed = this.RewriteAssembly(assembly.Definition, assumeCompatible, logPrefix: "   ");
                 if (changed)
                 {
@@ -143,7 +155,7 @@ namespace StardewModdingAPI.Framework.ModLoading
 
             // skip if already visited
             if (visitedAssemblyNames.Contains(assembly.Name.Name))
-                yield break;
+                yield return new AssemblyParseResult(file, null, AssemblyLoadStatus.AlreadyLoaded);
             visitedAssemblyNames.Add(assembly.Name.Name);
 
             // yield referenced assemblies
@@ -155,7 +167,7 @@ namespace StardewModdingAPI.Framework.ModLoading
             }
 
             // yield assembly
-            yield return new AssemblyParseResult(file, assembly);
+            yield return new AssemblyParseResult(file, assembly, AssemblyLoadStatus.Okay);
         }
 
         /****
diff --git a/src/StardewModdingAPI/Framework/ModLoading/AssemblyParseResult.cs b/src/StardewModdingAPI/Framework/ModLoading/AssemblyParseResult.cs
index 69c99afe..b56a776c 100644
--- a/src/StardewModdingAPI/Framework/ModLoading/AssemblyParseResult.cs
+++ b/src/StardewModdingAPI/Framework/ModLoading/AssemblyParseResult.cs
@@ -15,6 +15,9 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <summary>The assembly definition.</summary>
         public readonly AssemblyDefinition Definition;
 
+        /// <summary>The result of the assembly load.</summary>
+        public AssemblyLoadStatus Status;
+
 
         /*********
         ** Public methods
@@ -22,10 +25,12 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <summary>Construct an instance.</summary>
         /// <param name="file">The original assembly file.</param>
         /// <param name="assembly">The assembly definition.</param>
-        public AssemblyParseResult(FileInfo file, AssemblyDefinition assembly)
+        /// <param name="status">The result of the assembly load.</param>
+        public AssemblyParseResult(FileInfo file, AssemblyDefinition assembly, AssemblyLoadStatus status)
         {
             this.File = file;
             this.Definition = assembly;
+            this.Status = status;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/StardewModdingAPI/Framework/ModLoading/ModResolver.cs b/src/StardewModdingAPI/Framework/ModLoading/ModResolver.cs
index b75453b7..6b19db5c 100644
--- a/src/StardewModdingAPI/Framework/ModLoading/ModResolver.cs
+++ b/src/StardewModdingAPI/Framework/ModLoading/ModResolver.cs
@@ -71,9 +71,9 @@ namespace StardewModdingAPI.Framework.ModLoading
                     compatibility = (
                         from mod in compatibilityRecords
                         where
-                        mod.ID.Contains(key, StringComparer.InvariantCultureIgnoreCase)
-                        && (mod.LowerSemanticVersion == null || !manifest.Version.IsOlderThan(mod.LowerSemanticVersion))
-                        && !manifest.Version.IsNewerThan(mod.UpperSemanticVersion)
+                            mod.ID.Any(p => p.Matches(key, manifest))
+                            && (mod.LowerVersion == null || !manifest.Version.IsOlderThan(mod.LowerVersion))
+                            && !manifest.Version.IsNewerThan(mod.UpperVersion)
                         select mod
                     ).FirstOrDefault();
                 }
@@ -109,15 +109,25 @@ namespace StardewModdingAPI.Framework.ModLoading
                     ModCompatibility compatibility = mod.Compatibility;
                     if (compatibility?.Compatibility == ModCompatibilityType.AssumeBroken)
                     {
-                        bool hasOfficialUrl = !string.IsNullOrWhiteSpace(mod.Compatibility.UpdateUrl);
-                        bool hasUnofficialUrl = !string.IsNullOrWhiteSpace(mod.Compatibility.UnofficialUpdateUrl);
+#if SMAPI_1_x
+                        bool hasOfficialUrl = mod.Compatibility.UpdateUrls.Length > 0;
+                        bool hasUnofficialUrl = mod.Compatibility.UpdateUrls.Length > 1;
 
                         string reasonPhrase = compatibility.ReasonPhrase ?? "it's not compatible with the latest version of the game or SMAPI";
-                        string error = $"{reasonPhrase}. Please check for a version newer than {compatibility.UpperVersionLabel ?? compatibility.UpperVersion} here:";
+                        string error = $"{reasonPhrase}. Please check for a version newer than {compatibility.UpperVersionLabel ?? compatibility.UpperVersion.ToString()} here:";
                         if (hasOfficialUrl)
-                            error += !hasUnofficialUrl ? $" {compatibility.UpdateUrl}" : $"{Environment.NewLine}- official mod: {compatibility.UpdateUrl}";
+                            error += !hasUnofficialUrl ? $" {compatibility.UpdateUrls[0]}" : $"{Environment.NewLine}- official mod: {compatibility.UpdateUrls[0]}";
                         if (hasUnofficialUrl)
-                            error += $"{Environment.NewLine}- unofficial update: {compatibility.UnofficialUpdateUrl}";
+                            error += $"{Environment.NewLine}- unofficial update: {compatibility.UpdateUrls[1]}";
+#else
+                        string reasonPhrase = compatibility.ReasonPhrase ?? "it's no longer compatible";
+                        string error = $"{reasonPhrase}. Please check for a ";
+                        if (mod.Manifest.Version.Equals(compatibility.UpperVersion) && compatibility.UpperVersionLabel == null)
+                            error += "newer version";
+                        else
+                            error += $"version newer than {compatibility.UpperVersionLabel ?? compatibility.UpperVersion.ToString()}";
+                        error += " at " + string.Join(" or ", compatibility.UpdateUrls);
+#endif
 
                         mod.SetStatus(ModMetadataStatus.Failed, error);
                         continue;
@@ -161,7 +171,7 @@ namespace StardewModdingAPI.Framework.ModLoading
 #if !SMAPI_1_x
             {
                 var duplicatesByID = mods
-                    .GroupBy(mod => mod.Manifest.UniqueID?.Trim(), mod => mod, StringComparer.InvariantCultureIgnoreCase)
+                    .GroupBy(mod => mod.Manifest?.UniqueID?.Trim(), mod => mod, StringComparer.InvariantCultureIgnoreCase)
                     .Where(p => p.Count() > 1);
                 foreach (var group in duplicatesByID)
                 {
diff --git a/src/StardewModdingAPI/Framework/Models/Manifest.cs b/src/StardewModdingAPI/Framework/Models/Manifest.cs
index 1b5c2646..29c3517e 100644
--- a/src/StardewModdingAPI/Framework/Models/Manifest.cs
+++ b/src/StardewModdingAPI/Framework/Models/Manifest.cs
@@ -21,18 +21,18 @@ namespace StardewModdingAPI.Framework.Models
         public string Author { get; set; }
 
         /// <summary>The mod version.</summary>
-        [JsonConverter(typeof(ManifestFieldConverter))]
+        [JsonConverter(typeof(SFieldConverter))]
         public ISemanticVersion Version { get; set; }
 
         /// <summary>The minimum SMAPI version required by this mod, if any.</summary>
-        [JsonConverter(typeof(ManifestFieldConverter))]
+        [JsonConverter(typeof(SFieldConverter))]
         public ISemanticVersion MinimumApiVersion { get; set; }
 
         /// <summary>The name of the DLL in the directory that has the <see cref="Mod.Entry"/> method.</summary>
         public string EntryDll { get; set; }
 
         /// <summary>The other mods that must be loaded before this mod.</summary>
-        [JsonConverter(typeof(ManifestFieldConverter))]
+        [JsonConverter(typeof(SFieldConverter))]
         public IManifestDependency[] Dependencies { get; set; }
 
         /// <summary>The unique mod ID.</summary>
diff --git a/src/StardewModdingAPI/Framework/Models/ModCompatibility.cs b/src/StardewModdingAPI/Framework/Models/ModCompatibility.cs
index 90cbd237..d3a9c533 100644
--- a/src/StardewModdingAPI/Framework/Models/ModCompatibility.cs
+++ b/src/StardewModdingAPI/Framework/Models/ModCompatibility.cs
@@ -1,5 +1,5 @@
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
+using Newtonsoft.Json;
+using StardewModdingAPI.Framework.Serialisation;
 
 namespace StardewModdingAPI.Framework.Models
 {
@@ -9,60 +9,32 @@ namespace StardewModdingAPI.Framework.Models
         /*********
         ** Accessors
         *********/
-        /****
-        ** From config
-        ****/
         /// <summary>The unique mod IDs.</summary>
-        public string[] ID { get; set; }
+        [JsonConverter(typeof(SFieldConverter))]
+        public ModCompatibilityID[] ID { get; set; }
 
         /// <summary>The mod name.</summary>
         public string Name { get; set; }
 
         /// <summary>The oldest incompatible mod version, or <c>null</c> for all past versions.</summary>
-        public string LowerVersion { get; set; }
+        [JsonConverter(typeof(SFieldConverter))]
+        public ISemanticVersion LowerVersion { get; set; }
 
         /// <summary>The most recent incompatible mod version.</summary>
-        public string UpperVersion { get; set; }
+        [JsonConverter(typeof(SFieldConverter))]
+        public ISemanticVersion UpperVersion { get; set; }
 
         /// <summary>A label to show to the user instead of <see cref="UpperVersion"/>, when the manifest version differs from the user-facing version.</summary>
         public string UpperVersionLabel { get; set; }
 
-        /// <summary>The URL the user can check for an official updated version.</summary>
-        public string UpdateUrl { get; set; }
-
-        /// <summary>The URL the user can check for an unofficial updated version.</summary>
-        public string UnofficialUpdateUrl { get; set; }
+        /// <summary>The URLs the user can check for a newer version.</summary>
+        public string[] UpdateUrls { get; set; }
 
         /// <summary>The reason phrase to show in the warning, or <c>null</c> to use the default value.</summary>
         /// <example>"this version is incompatible with the latest version of the game"</example>
         public string ReasonPhrase { get; set; }
 
         /// <summary>Indicates how SMAPI should consider the mod.</summary>
-        public ModCompatibilityType Compatibility { get; set; }
-
-
-        /****
-        ** Injected
-        ****/
-        /// <summary>The semantic version corresponding to <see cref="LowerVersion"/>.</summary>
-        [JsonIgnore]
-        public ISemanticVersion LowerSemanticVersion { get; set; }
-
-        /// <summary>The semantic version corresponding to <see cref="UpperVersion"/>.</summary>
-        [JsonIgnore]
-        public ISemanticVersion UpperSemanticVersion { get; set; }
-
-
-        /*********
-        ** Private methods
-        *********/
-        /// <summary>The method called when the model finishes deserialising.</summary>
-        /// <param name="context">The deserialisation context.</param>
-        [OnDeserialized]
-        private void OnDeserialized(StreamingContext context)
-        {
-            this.LowerSemanticVersion = this.LowerVersion != null ? new SemanticVersion(this.LowerVersion) : null;
-            this.UpperSemanticVersion = this.UpperVersion != null ? new SemanticVersion(this.UpperVersion) : null;
-        }
+        public ModCompatibilityType Compatibility { get; set; } = ModCompatibilityType.AssumeBroken;
     }
 }
diff --git a/src/StardewModdingAPI/Framework/Models/ModCompatibilityID.cs b/src/StardewModdingAPI/Framework/Models/ModCompatibilityID.cs
new file mode 100644
index 00000000..98e70116
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/Models/ModCompatibilityID.cs
@@ -0,0 +1,57 @@
+using System;
+using Newtonsoft.Json;
+
+namespace StardewModdingAPI.Framework.Models
+{
+    /// <summary>Uniquely identifies a mod for compatibility checks.</summary>
+    internal class ModCompatibilityID
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The unique mod ID.</summary>
+        public string ID { get; set; }
+
+        /// <summary>The mod name to disambiguate non-unique IDs, or <c>null</c> to ignore the mod name.</summary>
+        public string Name { get; set; }
+
+        /// <summary>The author name to disambiguate non-unique IDs, or <c>null</c> to ignore the author.</summary>
+        public string Author { get; set; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        public ModCompatibilityID() { }
+
+        /// <summary>Construct an instance.</summary>
+        /// <param name="data">The mod ID or a JSON string matching the <see cref="ModCompatibilityID"/> fields.</param>
+        public ModCompatibilityID(string data)
+        {
+            // JSON can be stuffed into the ID string as a convenience hack to keep JSON mod lists
+            // formatted readably. The tradeoff is that the format is a bit more magical, but that's
+            // probably acceptable since players aren't meant to edit it. It's also fairly clear what
+            // the JSON strings do, if not necessarily how.
+            if (data.StartsWith("{")