Add DI extensions to Lambda Cloud service

Author: patchoulish

source/Lambda.Extensions.DependencyInjection/Cloud/LambdaCloudServiceOptions.cs

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+using System;
+
+using Microsoft;
+using Microsoft.Extensions;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Lambda.Cloud
+{
+	/// <summary>
+	/// Represents the options when registering an instance of the <see cref="LambdaCloudService"/>
+	/// class with an <see cref="IServiceCollection"/>.
+	/// </summary>
+	public sealed class LambdaCloudServiceOptions
+	{
+		/// <summary>
+		/// Gets or sets the base URL to use.
+		/// </summary>
+		public Uri BaseUrl { get; set; } =
+			LambdaCloudService.DefaultBaseUrl;
+
+		/// <summary>
+		/// Gets or sets the API key to use.
+		/// </summary>
+		public string ApiKey { get; set; }
+	}
+}

source/Lambda.Extensions.DependencyInjection/Cloud/ServiceCollectionExtensions.cs

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+using System;
+using System.Net;
+using System.Net.Http;
+
+using Microsoft;
+using Microsoft.Extensions;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Lambda.Cloud
+{
+	/// <summary>
+	/// Contains extension methods for
+	/// <see cref="IServiceCollection"/>.
+	/// </summary>
+	public static class ServiceCollectionExtensions
+	{
+		/// <summary>
+		/// The name to use for the named client.
+		/// </summary>
+		private const string LambdaCloudHttpClientName =
+			"lambda-cloud";
+
+		/// <summary>
+		/// Registers an instance of the <see cref="LambdaCloudService"/>
+		/// class with an <see cref="IServiceCollection"/>
+		/// using a named <see cref="HttpClient"/>.
+		/// </summary>
+		/// <param name="services">The service collection to register with.</param>
+		/// <param name="optionsCallback">The callback to configure the options for the instance with.</param>
+		/// <returns>An <see cref="IHttpClientBuilder"/> that can be used to configure the named client.</returns>
+		public static IHttpClientBuilder AddLambdaCloudHttpClient(
+			this IServiceCollection services,
+			Action<LambdaCloudServiceOptions> optionsCallback = default)
+		{
+			Guard.NotNull(
+				services,
+				nameof(services));
+
+			var options =
+				new LambdaCloudServiceOptions();
+
+			optionsCallback?
+				.Invoke(
+					options);
+
+			return services
+				.AddTransient<LambdaCloudDelegatingHandler>()
+				.AddHttpClient<ILambdaCloudService, LambdaCloudService>(
+					LambdaCloudHttpClientName,
+					(httpClient) =>
+					{
+						// Configure the base URL for the client.
+						httpClient.BaseAddress =
+							options.BaseUrl;
+
+						// Configure the default request headers for the client.
+						httpClient.DefaultRequestHeaders.Add(
+							$"Authorization",
+							$"Bearer {options.ApiKey}");
+					})
+				.AddHttpMessageHandler<LambdaCloudDelegatingHandler>();
+		}
+	}
+}

source/Lambda.Extensions.DependencyInjection/Guard.cs

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+using System;
+
+namespace Lambda
+{
+	/// <summary>
+	/// Contains guard clauses for throwing exceptions.
+	/// </summary>
+	internal static class Guard
+	{
+		/// <summary>
+		/// Throws an exception if the specified argument is null.
+		/// </summary>
+		/// <param name="argument">The argument specified.</param>
+		/// <param name="argumentName">The name of the argument specified.</param>
+		/// <exception cref="ArgumentNullException">
+		/// Thrown if the specified argument is null.
+		/// </exception>
+		public static void NotNull(
+			object argument,
+			string argumentName)
+		{
+			if (argument == null)
+			{
+				throw new ArgumentNullException(
+					argumentName);
+			}
+		}
+
+		/// <summary>
+		/// Throws an exception if the specified argument is null or empty.
+		/// </summary>
+		/// <param name="argument">The argument specified.</param>
+		/// <param name="argumentName">The name of the argument specified.</param>
+		/// <exception cref="ArgumentNullException">
+		/// Thrown if the specified argument is null.
+		/// </exception>
+		/// <exception cref="ArgumentException">
+		/// Thrown if the specified argument is empty.
+		/// </exception>
+		public static void NotNullOrEmpty(
+			string argument,
+			string argumentName)
+		{
+			if (argument == null)
+			{
+				throw new ArgumentNullException(
+					argumentName);
+			}
+
+			if (String.IsNullOrEmpty(argument))
+			{
+				throw new ArgumentException(
+					argumentName);
+			}
+		}
+	}
+}