using BuddyFinance.Common.Encryption;
using BuddyFinance.Integration.Models;
using BuddyFinance.Integration.Models.Enums;
using System;
using System.Diagnostics.Contracts;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Formatting;
using System.Web.Http;
using System.Web.Http.Controllers;
using System.Web.Http.Filters;


namespace BuddyFinance.WebApi.Filters
{
    public class AuthenticateAttribute : AuthorizationFilterAttribute
    {

        public override void OnAuthorization(HttpActionContext actionContext)
        {
            if (SkipAuthorization(actionContext)) return;

            BaseResult<object> result = new BaseResult<object>();
            var token = System.Web.HttpContext.Current.Request.Headers["X-Auth-Token"];

            if (string.IsNullOrWhiteSpace(token))
            {
                result = new BaseResult<object>((int)ResponseCodes.Unauthorized, "Unauthorized");
            }
            else
            {
                try
                {
                    var authCode_ = token.Decrypt();
                    var split = authCode_.Split('|');

                    DateTime issueDate = DateTime.Parse(split[1]);
                    TimeSpan validTimespan = TimeSpan.Parse(split[2]);

                    var isValid = DateTime.Now < issueDate.Add(validTimespan);
                    result.ErrorCode = isValid ? (int)ResponseCodes.Success : (int)ResponseCodes.Unauthorized;
                    result.ErrorMessage = isValid ? "Success" : "Unauthorized. Invalid access token";
                }
                catch (System.Exception ex)
                {
                    result.ErrorCode = (int)ResponseCodes.Unauthorized;
                    result.ErrorMessage = ex.Message + ". Unauthorized";
                }
            }

            if (result.ErrorCode != (int)ResponseCodes.Success)
            {
                var response = new HttpResponseMessage(System.Net.HttpStatusCode.OK)
                {
                    Content = new ObjectContent<BaseResult<object>>(result, new JsonMediaTypeFormatter())
                };

                actionContext.Response = response;  //new HttpUnauthorizedResult();
            }
        }

        private static bool SkipAuthorization(HttpActionContext actionContext)
        {
            Contract.Assert(actionContext != null);

            return actionContext.ActionDescriptor.GetCustomAttributes<AllowAnonymousAttribute>().Any()
                       || actionContext.ControllerContext.ControllerDescriptor.GetCustomAttributes<AllowAnonymousAttribute>().Any();
        }
    }
}