using System.Net.Http.Headers;
using System.Security.Cryptography;
using System.Text;
using Newtonsoft.Json;

Console.WriteLine("EasyLogon Testing tools");
Console.WriteLine("Mobile app emulator for Web application");

while (true)
{
	string? connectionId, encryptionKey, target = "http://localhost:4000";
	Mode mode = 0;

	while (true)
	{
		Console.WriteLine("Enter connection ID");
		connectionId = Console.ReadLine();

		if (string.IsNullOrWhiteSpace(connectionId))
			Console.WriteLine("\nError: Connection ID is required\n");
		else
			break;
	}

	while (true)
	{
		Console.WriteLine("Enter encryption key");
		encryptionKey = Console.ReadLine();

		if (string.IsNullOrWhiteSpace(encryptionKey))
			Console.WriteLine("\nError: Encryption key is required\n");
		else
			break;
	}

	while (true)
	{
		Console.WriteLine($"Enter website URL. Press return to keep default ({target})");
		string? input = Console.ReadLine();

		if (string.IsNullOrWhiteSpace(input))
			break;

		if (!Uri.IsWellFormedUriString(input, UriKind.Absolute))
			Console.WriteLine("\nError: Input is not a well formed URI string\n");
		else
		{
			target = input;
			break;
		}
	}

	while (true)
	{
		Console.WriteLine($"Select transmission mode. Press return to keep default");
		Console.WriteLine("0 - Default");
		Console.WriteLine("1 - Malformed model (Password is missing)");
		Console.WriteLine("2 - Malformed data (encrypted data is malformed)");

		string? input = Console.ReadLine();

		if (string.IsNullOrWhiteSpace(input))
			break;

		if (!int.TryParse(input, out int result))
			Console.WriteLine("\nError: Input is not a valid integer\n");
		else
		{
			mode = (Mode)Math.Clamp(result, 0, 2);
			break;
		}
	}

	Uri uri = new(new Uri(target), $"/api/send?id={connectionId}");

	HttpRequestMessage request = new(HttpMethod.Post, uri);
	string? data = EncryptData(encryptionKey, mode);

	if (string.IsNullOrWhiteSpace(data))
		continue;

	request.Content = new StringContent($"\"{data}\"", Encoding.UTF8, "application/json");

	if (target.Contains("azurewebsites.net"))
		try
		{
			Console.WriteLine("\nObtaining authentication token for the request (Test environment endpoint detected)");
			using HttpClient client = new HttpClient();

			HttpRequestMessage authRequest = new HttpRequestMessage(HttpMethod.Post, $"https://login.microsoftonline.com/e3382dae-1e6b-4b42-a26d-8cc6c96ee3ba/oauth2/token");
			authRequest.Content = new FormUrlEncodedContent(new Dictionary<string, string>
			{
				{ "grant_type", "client_credentials" },
				{ "client_id", "12dcdd03-f006-412b-b8e0-7beeb1510094" },
				{ "client_secret", "9Yy7Q~pkW8Q-9q.40o0FQcop-Zl1FRQtSgrya" },
				{ "resource", "api://53894705-c0d7-481a-b308-5d39185fe11c" }
			});

			HttpResponseMessage response = await client.SendAsync(authRequest);

			string content = await response.Content.ReadAsStringAsync();

			if (!response.IsSuccessStatusCode)
				throw new HttpRequestException($"Something went wrong (response from server: {response.StatusCode}\n{content})");

			Dictionary<string, string>? json = JsonConvert.DeserializeObject<Dictionary<string, string>>(content);

			if (string.IsNullOrWhiteSpace(json?["access_token"]))
				throw new HttpRequestException($"No access token were received (response from server: {response.StatusCode}\n{content})");

			request.Headers.Authorization = new("Bearer", json?["access_token"]);
		}
		catch (Exception e)
		{
			Console.WriteLine("Exception has been thrown");
			Console.WriteLine($"{e.GetType()}: {e.Message}");
			goto Exit;
		}

	Console.Write("Sending data to target... ");

	try
	{
		using HttpClient client = new();
		HttpResponseMessage response = client.Send(request);
		Console.Write("Done.\n");

		Console.WriteLine("\nRequest details:");
		Console.WriteLine($"Target URL: {request.RequestUri?.AbsoluteUri}");
		Console.WriteLine($"Data: ({request.Content.Headers.ContentType?.ToString()}) \"{data}\"");

		Console.WriteLine("\nResponse details:");
		Console.WriteLine($"Status: {(int)response.StatusCode} {response.StatusCode}");
	}
	catch (Exception e)
	{
		Console.WriteLine("Exception has been thrown");
		Console.WriteLine($"{e.GetType()}: {e.Message}");
	}

	Exit:
	Console.WriteLine("\nPress any key to continue...");
	Console.ReadKey();
	Console.Clear();
}

string? EncryptData(string encryptionKey, Mode mode)
{
	// Represents CredentialModel data
	// https://dev.azure.com/FoxDevStudio/EasyLogon/_wiki/wikis/Documentation/40/Webapp-API-endpoints?anchor=remarks
	var mockData = new
	{
		Id = Guid.NewGuid().ToString(),
		Name = "Mock data",
		TargetResource = "ezlog.app",
		Login = "xfox",
		Password = mode == Mode.MalformedModel ? null : "Qwerty123",
		UseCount = 3
	};

	string rawData = JsonConvert.SerializeObject(mockData);
	byte[] dataBytes = Encoding.UTF8.GetBytes(rawData);
	byte[] keyBytes = Convert.FromBase64String(encryptionKey);

	using Aes aes = Aes.Create();

	aes.Key = keyBytes;
	aes.Padding = PaddingMode.PKCS7;
	aes.Mode = CipherMode.ECB;

	try
	{
		using ICryptoTransform encryptor = aes.CreateEncryptor();
		byte[] encryptedBytes = encryptor.TransformFinalBlock(dataBytes, 0, dataBytes.Length);
		string data = Convert.ToBase64String(encryptedBytes);
		return mode == Mode.MalformedData ? string.Concat(data.Reverse()) : data;
	}
	catch (Exception e)
	{
		Console.WriteLine($"Error during encryption: {e.GetType()}: {e.Message}");
		return null;
	}
}

enum Mode
{
	Default = 0,
	MalformedModel = 1,
	MalformedData = 2
}