using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Net.Http;
using System.Security.Claims;
using System.Web;
using Kreta.Ellenorzo.Domain.VN.Common;
using Kreta.Ellenorzo.Enums;

namespace Kreta.Ellenorzo.WebApi.VN.Logic
{
    internal static class FelhasznaloLogic
    {
        public static MobileUser GetFelhasznalo()
        {
            return HttpContext.Current.Items.Contains("MobileUser")
                ? (MobileUser)HttpContext.Current.Items["MobileUser"]
                : new MobileUser(GetInstituteCode(), GetStudentId(), GetUserName(), GetTutelaryId(), GetRoles(), GetSchoolYearId(), GetApiSecurity(), GetUserIdpUniqueId(), GetStudentIdpUniqueId(), GetInstituteUniqueId());
        }

        private static string GetInstituteCode()
        {
            return GetClaims("kreta:institute_code").Single();
        }

        private static Guid GetInstituteUniqueId()
        {
            return new Guid(GetClaims("kreta:institute_unique_id").Single());
        }

        private static ApiSecurity GetApiSecurity()
        {
            if (bool.Parse(ConfigurationManager.AppSettings["IsApiSecurityEnabled"]))
            {
                var header = ((HttpRequestMessage)HttpContext.Current.Items["MS_HttpRequestMessage"]).Headers;
                return new ApiSecurity(header.Authorization.Parameter, header.First(x => x.Key == "s").Value.First());
            }
            else
            {
                return null;
            }
        }

        private static int GetInstituteUserId()
        {
            var claim = GetClaims("kreta:institute_user_id").Single();
            return int.Parse(claim);
        }

        private static int GetSchoolYearId()
        {
            var claim = GetClaims("kreta:school_year_id").Single();
            return int.Parse(claim);
        }

        private static int? GetTutelaryId()
            => HasRole(FelhasznaloSzerepkor.Gondviselo) ? GetInstituteUserId() : (int?)null;

        private static int GetStudentId()
            => HasRole(FelhasznaloSzerepkor.Gondviselo) ? int.Parse(GetClaims("kreta:student_id").Single()) : GetInstituteUserId();

        private static Guid GetUserIdpUniqueId()
        {
            return new Guid(GetClaims("kreta:institute_user_idp_unique_id").Single());
        }

        private static Guid GetStudentIdpUniqueId()
            => HasRole(FelhasznaloSzerepkor.Gondviselo) ? new Guid(GetClaims("kreta:student_idp_unique_id").Single()) : GetUserIdpUniqueId();

        private static string GetUserName()
        {
            return GetClaims("kreta:user_name").Single();
        }

        private static IEnumerable<FelhasznaloSzerepkor> GetRoles()
        {
            var result = new List<FelhasznaloSzerepkor>();

            var roles = GetClaims(ClaimTypes.Role);
            foreach (var role in roles)
            {
                if (Enum.TryParse(role, out FelhasznaloSzerepkor enumValue))
                {
                    result.Add(enumValue);
                }
            }

            return result;
        }

        private static IEnumerable<string> GetClaims(string type)
        {
            return ClaimsPrincipal.Current.Claims.Where(x => x.Type == type).Select(x => x.Value);
        }

        private static bool HasRole(FelhasznaloSzerepkor felhasznaloSzerepkor) => GetRoles().Count(x => x == felhasznaloSzerepkor) == 1;
    }
}