Add interaction router with tests

src/Giveaways/Services/InteractionRouter.cs

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+using System;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using Discord.Interactions;
+using Microsoft.Extensions.Options;
+
+namespace Giveaways.Services;
+
+/// <summary>
+/// Represents a service for binding custom interactions to their corresponding custom IDs.
+/// </summary>
+/// <remarks>
+/// Initializes a new instance of the <see cref="InteractionRouter"/> class.
+/// </remarks>
+/// <param name="options">The options containing the wild card expression.</param>
+public class InteractionRouter(IOptions<InteractionServiceConfig> options)
+{
+    private readonly string _wildCardExpression = options.Value.WildCardExpression;
+
+    /// <summary>
+    /// Binds a delegate to its corresponding custom ID by applying any provided arguments.
+    /// </summary>
+    /// <param name="func">The delegate to bind.</param>
+    /// <param name="args">The arguments to apply.</param>
+    /// <returns>The custom ID bound with the delegate and arguments applied.</returns>
+    public string Bind(Delegate func, params object[] args)
+    {
+        var pattern = GetCustomIdPattern(func);
+        var sb = new StringBuilder(pattern);
+
+        for (int argPos = 0; argPos < args.Length; argPos++)
+        {
+            int startIndex = sb.ToString().IndexOf(_wildCardExpression, StringComparison.Ordinal);
+            sb.Replace(_wildCardExpression, args[argPos].ToString(), startIndex, _wildCardExpression.Length);
+        }
+
+        return sb.ToString();
+    }
+
+    /// <summary>
+    /// Retrieves the custom ID pattern associated with a delegate.
+    /// </summary>
+    /// <param name="func">The delegate.</param>
+    /// <returns>The custom ID pattern associated with the delegate.</returns>
+    /// <exception cref="ArgumentException">
+    /// Thrown when the provided delegate doesn't have an interaction attribute.
+    /// </exception>
+    public static string GetCustomIdPattern(Delegate func)
+    {
+        foreach (Attribute attribute in func.Method.GetCustomAttributes())
+        {
+            switch (attribute)
+            {
+                case ModalInteractionAttribute modal:
+                    return modal.CustomId;
+                case ComponentInteractionAttribute component:
+                    return component.CustomId;
+            }
+        }
+
+        throw new ArgumentException("The provided delegate doesn't have an interaction attribute.", nameof(func));
+    }
+
+    public static string GetCustomIdPrefix(Delegate func) => GetCustomIdPattern(func).Split(":").First();
+}

test/Giveaways.Tests/MockedModule.cs

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+using System;
+using System.Threading.Tasks;
+using Discord.Interactions;
+
+namespace Giveaways.Tests;
+
+/// <summary>
+/// Represents a module for unit testing.
+/// </summary>
+internal sealed class MockedModule : ModuleBase
+{
+    [ComponentInteraction("interaction:*:*")]
+    public Task InteractionAsync(string arg1, string arg2) => throw new NotImplementedException();
+}

test/Giveaways.Tests/Services/InteractionRouterTests.cs

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+using Bogus;
+using Discord.Interactions;
+using Giveaways.Services;
+using Microsoft.Extensions.Options;
+using Moq;
+using Xunit;
+
+namespace Giveaways.Tests;
+
+/// <summary>
+/// Provides unit test cases for <see cref="InteractionRouter"/>.
+/// </summary>
+public class InteractionRouterTests : TestsBase
+{
+    [Fact]
+    public void InteractionRouter_Binds_CustomID()
+    {
+        var optionsMock = new Mock<IOptions<InteractionServiceConfig>>();
+        optionsMock.Setup(x => x.Value).Returns(new InteractionServiceConfig());
+
+        var moduleMock = new MockedModule();
+        var func = moduleMock.InteractionAsync;
+
+        var arg1 = Faker.Lorem.Word();
+        var arg2 = Faker.Lorem.Word();
+
+        var routerMock = new Mock<InteractionRouter>(optionsMock.Object);
+        var id = routerMock.Object.Bind(func, arg1, arg2);
+
+        var prefix = InteractionRouter.GetCustomIdPrefix(func);
+
+        Assert.Equal($"{prefix}:{arg1}:{arg2}", id);
+    }
+}