Implement AlamoLanguageSupportService

Author: gruenwaldlk

PG.StarWarsGame.Components.Localisation/PG.StarWarsGame.Components.Localisation/Exceptions/InvalidDefaultLanguageDefinitionException.cs

@@ -0,0 +1,25 @@
+// Copyright (c) Alamo Engine Tools and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for details.
+
+using System;
+
+namespace PG.StarWarsGame.Components.Localisation.Exceptions;
+
+/// <inheritdoc />
+public class InvalidDefaultLanguageDefinitionException : Exception
+{
+    /// <inheritdoc />
+    public InvalidDefaultLanguageDefinitionException()
+    {
+    }
+
+    /// <inheritdoc />
+    public InvalidDefaultLanguageDefinitionException(string message) : base(message)
+    {
+    }
+
+    /// <inheritdoc />
+    public InvalidDefaultLanguageDefinitionException(string message, Exception inner) : base(message, inner)
+    {
+    }
+}

PG.StarWarsGame.Components.Localisation/PG.StarWarsGame.Components.Localisation/LocalisationServiceContribution.cs

@@ -1,6 +1,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using PG.Commons.Attributes;
 using PG.Commons.Extensibility;
+using PG.StarWarsGame.Components.Localisation.Services;
 
 namespace PG.StarWarsGame.Components.Localisation;
 
@@ -11,6 +12,7 @@ public class LocalisationServiceContribution : IServiceContribution
     /// <inheritdoc />
     public void ContributeServices(IServiceCollection serviceCollection)
     {
-        // NOP
+        serviceCollection
+            .AddSingleton<IAlamoLanguageSupportService>(sp => new AlamoLanguageSupportService(sp));
     }
-}
+}

PG.StarWarsGame.Components.Localisation/PG.StarWarsGame.Components.Localisation/Services/AlamoLanguageSupportService.cs

@@ -0,0 +1,59 @@
+// Copyright (c) Alamo Engine Tools and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for details.
+
+using System;
+using System.Linq;
+using System.Reflection;
+using PG.Commons.Services;
+using PG.StarWarsGame.Components.Localisation.Attributes;
+using PG.StarWarsGame.Components.Localisation.Exceptions;
+using PG.StarWarsGame.Components.Localisation.Languages;
+
+namespace PG.StarWarsGame.Components.Localisation.Services;
+
+/// <inheritdoc cref="PG.StarWarsGame.Components.Localisation.Services.IAlamoLanguageSupportService" />
+public class AlamoLanguageSupportService : ServiceBase, IAlamoLanguageSupportService
+{
+    private IAlamoLanguageDefinition _fallbackAlamoLanguageDefinition;
+
+    /// <inheritdoc />
+    public AlamoLanguageSupportService(IServiceProvider services) : base(services)
+    {
+        _fallbackAlamoLanguageDefinition = GetDefaultLanguageDefinition();
+    }
+
+    /// <inheritdoc />
+    public bool IsBuiltInLanguageDefinition(IAlamoLanguageDefinition definition)
+    {
+        return definition.GetType().GetCustomAttribute(typeof(OfficiallySupportedLanguageAttribute)) != null;
+    }
+
+    /// <inheritdoc />
+    public IAlamoLanguageDefinition GetFallBackLanguageDefinition()
+    {
+        return _fallbackAlamoLanguageDefinition;
+    }
+
+    /// <inheritdoc />
+    public IAlamoLanguageSupportService WithOverrideFallbackLanguage(IAlamoLanguageDefinition definition)
+    {
+        _fallbackAlamoLanguageDefinition = definition;
+        return this;
+    }
+
+    /// <inheritdoc />
+    public IAlamoLanguageDefinition GetDefaultLanguageDefinition()
+    {
+        var languageDefinitions = AppDomain.CurrentDomain.GetAssemblies()
+            .SelectMany(assemblyTypes => assemblyTypes.GetTypes())
+            .Where(assemblyType => typeof(IAlamoLanguageDefinition).IsAssignableFrom(assemblyType) &&
+                                   assemblyType is { IsClass: true, IsAbstract: false })
+            .Where(t => t.GetCustomAttribute(typeof(DefaultLanguageAttribute)) != null)
+            .ToList();
+        if (languageDefinitions.Count != 1)
+            throw new InvalidDefaultLanguageDefinitionException(languageDefinitions.Count > 1
+                ? "Multiple default languages have been defined."
+                : "No default language has been defined.");
+        return (IAlamoLanguageDefinition)Activator.CreateInstance(languageDefinitions[0]);
+    }
+}