/*
This file is part of the Notesnook Sync Server project (https://notesnook.com/)

Copyright (C) 2023 Streetwriters (Private) Limited

This program is free software: you can redistribute it and/or modify
it under the terms of the Affero GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Affero GNU General Public License for more details.

You should have received a copy of the Affero GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Text.Json;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using IdentityServer4;
using IdentityServer4.Models;
using IdentityServer4.Stores;
using IdentityServer4.Validation;
using Microsoft.AspNetCore.Identity;
using Streetwriters.Common.Enums;
using Streetwriters.Common.Models;
using Streetwriters.Identity.Interfaces;
using Streetwriters.Identity.Models;
using static IdentityModel.OidcConstants;

namespace Streetwriters.Identity.Validation
{
    public class EmailGrantValidator : IExtensionGrantValidator
    {
        private UserManager<User> UserManager { get; set; }
        private SignInManager<User> SignInManager { get; set; }
        private IMFAService MFAService { get; set; }
        private ITokenGenerationService TokenGenerationService { get; set; }
        private JwtRequestValidator JWTRequestValidator { get; set; }
        private IResourceStore ResourceStore { get; set; }
        private IUserClaimsPrincipalFactory<User> PrincipalFactory { get; set; }
        public EmailGrantValidator(UserManager<User> userManager, SignInManager<User> signInManager, IMFAService mfaService, ITokenGenerationService tokenGenerationService,
        IResourceStore resourceStore, IUserClaimsPrincipalFactory<User> principalFactory)
        {
            UserManager = userManager;
            SignInManager = signInManager;
            MFAService = mfaService;
            TokenGenerationService = tokenGenerationService;
            ResourceStore = resourceStore;
            PrincipalFactory = principalFactory;
        }

        public string GrantType => Config.EMAIL_GRANT_TYPE;


        public async Task ValidateAsync(ExtensionGrantValidationContext context)
        {
            var email = context.Request.Raw["email"];
            var clientId = context.Request.ClientId;
            var user = await UserManager.FindRegisteredUserAsync(email, clientId);
            if (user == null)
            {
                user = new User
                {
                    Id = MongoDB.Bson.ObjectId.GenerateNewId(),
                    Email = email,
                    UserName = email,
                    NormalizedEmail = email,
                    NormalizedUserName = email,
                    EmailConfirmed = false,
                    SecurityStamp = ""
                };
            }
            var isMultiFactor = await UserManager.GetTwoFactorEnabledAsync(user);

            var primaryMethod = isMultiFactor ? MFAService.GetPrimaryMethod(user) : MFAMethods.Email;
            var secondaryMethod = MFAService.GetSecondaryMethod(user);
            var sendPhoneNumber = primaryMethod == MFAMethods.SMS || secondaryMethod == MFAMethods.SMS;

            context.Result.CustomResponse = new Dictionary<string, object>
            {
                ["additional_data"] = new MFARequiredResponse
                {
                    PhoneNumber = sendPhoneNumber ? Regex.Replace(user.PhoneNumber, @"\d(?!\d{0,3}$)", "*") : null,
                    PrimaryMethod = primaryMethod,
                    SecondaryMethod = secondaryMethod,
                }
            };
            context.Result.IsError = false;
            context.Result.Subject = await TokenGenerationService.TransformTokenRequestAsync(context.Request, user, GrantType, new string[] { Config.MFA_GRANT_TYPE_SCOPE });
        }


        string Pluralize(int? value, string singular, string plural)
        {
            if (value == null) return $"0 {plural}";
            return value == 1 ? $"{value} {singular}" : $"{value} {plural}";
        }
    }
}