add initial multiplayer API (#480)

7 files changed, 55 insertions, 2 deletions

diff --git a/src/SMAPI/Framework/ModHelpers/ModHelper.cs b/src/SMAPI/Framework/ModHelpers/ModHelper.cs
index b5758d21..1f37a1be 100644
--- a/src/SMAPI/Framework/ModHelpers/ModHelper.cs
+++ b/src/SMAPI/Framework/ModHelpers/ModHelper.cs
@@ -45,6 +45,9 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <summary>An API for managing console commands.</summary>
         public ICommandHelper ConsoleCommands { get; }
 
+        /// <summary>Provides multiplayer utilities.</summary>
+        public IMultiplayerHelper Multiplayer { get; }
+
         /// <summary>An API for reading translations stored in the mod's <c>i18n</c> folder, with one file per locale (like <c>en.json</c>) containing a flat key => value structure. Translations are fetched with locale fallback, so missing translations are filled in from broader locales (like <c>pt-BR.json</c> &lt; <c>pt.json</c> &lt; <c>default.json</c>).</summary>
         public ITranslationHelper Translation { get; }
 
@@ -66,7 +69,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="deprecationManager">Manages deprecation warnings.</param>
         /// <exception cref="ArgumentNullException">An argument is null or empty.</exception>
         /// <exception cref="InvalidOperationException">The <paramref name="modDirectory"/> path does not exist on disk.</exception>
-        public ModHelper(string modID, string modDirectory, JsonHelper jsonHelper, IContentHelper contentHelper, ICommandHelper commandHelper, IModRegistry modRegistry, IReflectionHelper reflectionHelper, ITranslationHelper translationHelper, IEnumerable<IContentPack> contentPacks, Func<string, IManifest, IContentPack> createContentPack, DeprecationManager deprecationManager)
+        public ModHelper(string modID, string modDirectory, JsonHelper jsonHelper, IContentHelper contentHelper, ICommandHelper commandHelper, IModRegistry modRegistry, IReflectionHelper reflectionHelper, IMultiplayerHelper multiplayer, ITranslationHelper translationHelper, IEnumerable<IContentPack> contentPacks, Func<string, IManifest, IContentPack> createContentPack, DeprecationManager deprecationManager)
             : base(modID)
         {
             // validate directory
@@ -82,6 +85,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
             this.ModRegistry = modRegistry ?? throw new ArgumentNullException(nameof(modRegistry));
             this.ConsoleCommands = commandHelper ?? throw new ArgumentNullException(nameof(commandHelper));
             this.Reflection = reflectionHelper ?? throw new ArgumentNullException(nameof(reflectionHelper));
+            this.Multiplayer = multiplayer ?? throw new ArgumentNullException(nameof(multiplayer));
             this.Translation = translationHelper ?? throw new ArgumentNullException(nameof(translationHelper));
             this.ContentPacks = contentPacks.ToArray();
             this.CreateContentPack = createContentPack;
diff --git a/src/SMAPI/Framework/ModHelpers/MultiplayerHelper.cs b/src/SMAPI/Framework/ModHelpers/MultiplayerHelper.cs
new file mode 100644
index 00000000..7a8da1d0
--- /dev/null
+++ b/src/SMAPI/Framework/ModHelpers/MultiplayerHelper.cs
@@ -0,0 +1,31 @@
+namespace StardewModdingAPI.Framework.ModHelpers
+{
+    /// <summary>Provides multiplayer utilities.</summary>
+    internal class MultiplayerHelper : BaseHelper, IMultiplayerHelper
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>SMAPI's core multiplayer utility.</summary>
+        private readonly SMultiplayer Multiplayer;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="modID">The unique ID of the relevant mod.</param>
+        /// <param name="multiplayer">SMAPI's core multiplayer utility.</param>
+        public MultiplayerHelper(string modID, SMultiplayer multiplayer)
+            : base(modID)
+        {
+            this.Multiplayer = multiplayer;
+        }
+
+        /// <summary>Get a new multiplayer ID.</summary>
+        public long GetNewID()
+        {
+            return this.Multiplayer.getNewID();
+        }
+    }
+}
diff --git a/src/SMAPI/Framework/SGame.cs b/src/SMAPI/Framework/SGame.cs
index 7578473b..b206879c 100644
--- a/src/SMAPI/Framework/SGame.cs
+++ b/src/SMAPI/Framework/SGame.cs
@@ -126,6 +126,9 @@ namespace StardewModdingAPI.Framework
         /// <summary>SMAPI's content manager.</summary>
         public ContentCore ContentCore { get; private set; }
 
+        /// <summary>The game's core multiplayer utility.</summary>
+        public SMultiplayer Multiplayer => (SMultiplayer)Game1.multiplayer;
+
         /// <summary>Whether SMAPI should log more information about the game context.</summary>
         public bool VerboseLogging { get; set; }
 
diff --git a/src/SMAPI/IModHelper.cs b/src/SMAPI/IModHelper.cs
index e9554fdc..5e39161d 100644
--- a/src/SMAPI/IModHelper.cs
+++ b/src/SMAPI/IModHelper.cs
@@ -21,6 +21,9 @@ namespace StardewModdingAPI
         /// <summary>Metadata about loaded mods.</summary>
         IModRegistry ModRegistry { get; }
 
+        /// <summary>Provides multiplayer utilities.</summary>
+        IMultiplayerHelper Multiplayer { get; }
+
         /// <summary>An API for managing console commands.</summary>
         ICommandHelper ConsoleCommands { get; }
 
diff --git a/src/SMAPI/IMultiplayerHelper.cs b/src/SMAPI/IMultiplayerHelper.cs
new file mode 100644
index 00000000..ac00b970
--- /dev/null
+++ b/src/SMAPI/IMultiplayerHelper.cs
@@ -0,0 +1,9 @@
+namespace StardewModdingAPI
+{
+    /// <summary>Provides multiplayer utilities.</summary>
+    public interface IMultiplayerHelper : IModLinked
+    {
+        /// <summary>Get a new multiplayer ID.</summary>
+        long GetNewID();
+    }
+}
diff --git a/src/SMAPI/Program.cs b/src/SMAPI/Program.cs
index 2325e79a..eaeb5f1d 100644
--- a/src/SMAPI/Program.cs
+++ b/src/SMAPI/Program.cs
@@ -807,6 +807,7 @@ namespace StardewModdingAPI
                             IContentHelper contentHelper = new ContentHelper(contentCore, contentManager, metadata.DirectoryPath, manifest.UniqueID, metadata.DisplayName, monitor);
                             IReflectionHelper reflectionHelper = new ReflectionHelper(manifest.UniqueID, metadata.DisplayName, this.Reflection, this.DeprecationManager);
                             IModRegistry modRegistryHelper = new ModRegistryHelper(manifest.UniqueID, this.ModRegistry, proxyFactory, monitor);
+                            IMultiplayerHelper multiplayerHelper = new MultiplayerHelper(manifest.UniqueID, this.GameInstance.Multiplayer);
                             ITranslationHelper translationHelper = new TranslationHelper(manifest.UniqueID, manifest.Name, contentCore.GetLocale(), contentCore.Language);
 
                             IContentPack CreateTransitionalContentPack(string packDirPath, IManifest packManifest)
@@ -817,7 +818,7 @@ namespace StardewModdingAPI
                                 return new ContentPack(packDirPath, packManifest, packContentHelper, this.JsonHelper);
                             }
 
-                            modHelper = new ModHelper(manifest.UniqueID, metadata.DirectoryPath, jsonHelper, contentHelper, commandHelper, modRegistryHelper, reflectionHelper, translationHelper, contentPacks, CreateTransitionalContentPack, this.DeprecationManager);
+                            modHelper = new ModHelper(manifest.UniqueID, metadata.DirectoryPath, jsonHelper, contentHelper, commandHelper, modRegistryHelper, reflectionHelper, multiplayerHelper, translationHelper, contentPacks, CreateTransitionalContentPack, this.DeprecationManager);
                         }
 
                         // get mod instance
diff --git a/src/SMAPI/StardewModdingAPI.csproj b/src/SMAPI/StardewModdingAPI.csproj
index f6a16e5f..e0125c9b 100644
--- a/src/SMAPI/StardewModdingAPI.csproj
+++ b/src/SMAPI/StardewModdingAPI.csproj
@@ -102,6 +102,7 @@
     <Compile Include="Framework\ModData\ParsedModDataRecord.cs" />
     <Compile Include="Framework\Models\ManifestContentPackFor.cs" />
     <Compile Include="Framework\Models\SMetadata.cs" />
+    <Compile Include="Framework\ModHelpers\MultiplayerHelper.cs" />
     <Compile Include="Framework\ModLoading\Finders\EventFinder.cs" />
     <Compile Include="Framework\ModLoading\Finders\FieldFinder.cs" />
     <Compile Include="Framework\ModLoading\Finders\MethodFinder.cs" />
@@ -151,6 +152,7 @@
     <Compile Include="Framework\Utilities\PathUtilities.cs" />
     <Compile Include="IContentPack.cs" />
     <Compile Include="IManifestContentPackFor.cs" />
+    <Compile Include="IMultiplayerHelper.cs" />
     <Compile Include="IReflectedField.cs" />
     <Compile Include="IReflectedMethod.cs" />
     <Compile Include="IReflectedProperty.cs" />