using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading;
using System.Threading.Tasks;
using Moq;
using Moq.Protected;

namespace AMWD.Common.Test
{
	/// <summary>
	/// Wrapps the <see cref="Mock{HttpMessageHandler}"/> including the setup.
	/// </summary>
	public class HttpMessageHandlerMoq
	{
		/// <summary>
		/// Initializes a new instance of the <see cref="HttpMessageHandlerMoq"/> class.
		/// </summary>
		public HttpMessageHandlerMoq()
		{
			Response = new() { StatusCode = HttpStatusCode.OK };
			Callbacks = new();

			Mock = new();
			Mock.Protected()
				.Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>())
				.Callback<HttpRequestMessage, CancellationToken>(async (req, _) =>
				{
					var callback = new HttpMessageRequestCallback
					{
						Headers = req.Headers,
						Method = req.Method,
						Properties = req.Properties,
						RequestUri = req.RequestUri,
						Version = req.Version
					};

					if (req.Content != null)
					{
						callback.ContentBytes = await req.Content.ReadAsByteArrayAsync();
						callback.ContentString = await req.Content.ReadAsStringAsync();
					}

					Callbacks.Add(callback);
				})
				.ReturnsAsync(Response);
		}

		/// <summary>
		/// Gets the mocked <see cref="HttpMessageHandler"/>.
		/// </summary>
		public Mock<HttpMessageHandler> Mock { get; }

		/// <summary>
		/// Gets the placed request.
		/// </summary>
		public List<HttpMessageRequestCallback> Callbacks { get; private set; }

		/// <summary>
		/// Gets the HTTP response, that should be "sent".
		/// </summary>
		public HttpResponseMessage Response { get; private set; }

		/// <summary>
		/// Disposes and resets the <see cref="Response"/> and <see cref="Callbacks"/>.
		/// </summary>
		public void Reset()
		{
			Response.Dispose();
			Response = new() { StatusCode = HttpStatusCode.OK };

			Callbacks.Clear();
		}

		/// <summary>
		/// Verifies the number of calls to the HTTP request.
		/// </summary>
		/// <param name="times"></param>
		public void Verify(Times times)
			=> Mock.Protected().Verify("SendAsync", times, ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());

		/// <summary>
		/// Represents the placed HTTP request.
		/// </summary>
		public class HttpMessageRequestCallback
		{
			/// <summary>
			/// Gets the contents of the HTTP message.
			/// </summary>
			public byte[] ContentBytes { get; internal set; }

			/// <summary>
			/// Gets the contents of the HTTP message.
			/// </summary>
			public string ContentString { get; internal set; }

			/// <summary>
			/// Gets the collection of HTTP request headers.
			/// </summary>
			public HttpRequestHeaders Headers { get; internal set; }

			/// <summary>
			/// Gets the HTTP method used by the HTTP request message.
			/// </summary>
			public HttpMethod Method { get; internal set; }

			/// <summary>
			/// Gets of properties for the HTTP request.
			/// </summary>
			public IDictionary<string, object> Properties { get; internal set; }

			/// <summary>
			/// Gets the <see cref="Uri"/> used for the HTTP request.
			/// </summary>
			public Uri RequestUri { get; internal set; }

			/// <summary>
			/// Gets the <see cref="RequestUri"/> string representation.
			/// </summary>
			public string RequestUrl => RequestUri?.ToString();

			/// <summary>
			/// Gets the HTTP message version.
			/// </summary>
			public Version Version { get; internal set; }
		}
	}
}