using Neo.Afx.Services.Security;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Security.Claims;
using System.Threading;
using System.Threading.Tasks;

namespace Neo.LegitimateLicences.Api.Helpers
{
    public class AuthorizationHeaderHandler : DelegatingHandler
    {
        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            IEnumerable<string> apiKeyHeaderValues = null;
            IEnumerable<string> userKeyHeaderValues = null;
            var isValidUser = false;
            var taskCompletionSource = new TaskCompletionSource<HttpResponseMessage>();

            if (request.RequestUri.AbsolutePath.ToLower().Contains("/1.0/login")) //login only requires an API key
            {
                if (request.Headers.TryGetValues("api_Key", out apiKeyHeaderValues))
                {
                    var apiKeyHeaderValue = apiKeyHeaderValues.First();
                    if (apiKeyHeaderValue == ConfigurationManager.AppSettings["LegitimateLicencesApiKey"])
                    {
                        var identity = new ClaimsIdentity();
                        var principal = new ClaimsPrincipal(identity);

                        Thread.CurrentPrincipal = principal;
                        isValidUser = true;

                        await base.SendAsync(request, cancellationToken).ContinueWith(t => taskCompletionSource.SetResult(t.Result));
                    }
                }
            }
            else
            {
                if (request.Headers.TryGetValues("api_Key", out apiKeyHeaderValues) && request.Headers.TryGetValues("api_User", out userKeyHeaderValues))
                {
                    var apiKeyHeaderValue = apiKeyHeaderValues.First();
                    var userKeyHeaderValue = userKeyHeaderValues.First();
                    var securityDatabase = new SecurityDatabase();
                    var user = securityDatabase.GetUser(userKeyHeaderValue);                    

                    if (apiKeyHeaderValue == ConfigurationManager.AppSettings["LegitimateLicencesApiKey"] && user != null)
                    {
                        var nameClaim = new Claim(ClaimTypes.Name, user.Email);
                        var emailClaim = new Claim(ClaimTypes.Email, user.Email);
                        var userClaim = new Claim("UserID", user.UserID.ToString());
                        var identity = new ClaimsIdentity(new[] { nameClaim, emailClaim, userClaim }, "api_Key");
                        var principal = new ClaimsPrincipal(identity);

                        Thread.CurrentPrincipal = principal;
                        isValidUser = true;

                        await base.SendAsync(request, cancellationToken).ContinueWith(t => taskCompletionSource.SetResult(t.Result));
                    }
                }
            }
            
            if (!isValidUser)
            {
                taskCompletionSource.SetResult(new HttpResponseMessage(HttpStatusCode.Unauthorized));
            }

            return await taskCompletionSource.Task;
        }
    }
}