using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Text.Json;
using System.Threading.Tasks;
using Bit.Core.Context;
using Bit.Core.Entities;
using Bit.Core.Identity;
using Bit.Core.Models.Data;
using Bit.Core.Repositories;
using Bit.Core.Services;
using Bit.Core.Settings;
using IdentityModel;
using IdentityServer4.Extensions;
using IdentityServer4.Validation;
using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.Logging;

namespace Bit.Core.IdentityServer
{
    public class CustomTokenRequestValidator : BaseRequestValidator<CustomTokenRequestValidationContext>,
        ICustomTokenRequestValidator
    {
        private UserManager<User> _userManager;
        private readonly ISsoConfigRepository _ssoConfigRepository;
        private readonly IOrganizationRepository _organizationRepository;

        public CustomTokenRequestValidator(
            UserManager<User> userManager,
            IDeviceRepository deviceRepository,
            IDeviceService deviceService,
            IUserService userService,
            IEventService eventService,
            IOrganizationDuoWebTokenProvider organizationDuoWebTokenProvider,
            IOrganizationRepository organizationRepository,
            IOrganizationUserRepository organizationUserRepository,
            IApplicationCacheService applicationCacheService,
            IMailService mailService,
            ILogger<ResourceOwnerPasswordValidator> logger,
            ICurrentContext currentContext,
            GlobalSettings globalSettings,
            IPolicyRepository policyRepository,
            ISsoConfigRepository ssoConfigRepository,
            IUserRepository userRepository,
            ICaptchaValidationService captchaValidationService)
            : base(userManager, deviceRepository, deviceService, userService, eventService,
                  organizationDuoWebTokenProvider, organizationRepository, organizationUserRepository,
                  applicationCacheService, mailService, logger, currentContext, globalSettings, policyRepository,
                  userRepository, captchaValidationService)
        {
            _userManager = userManager;
            _ssoConfigRepository = ssoConfigRepository;
            _organizationRepository = organizationRepository;
        }

        public async Task ValidateAsync(CustomTokenRequestValidationContext context)
        {
            string[] allowedGrantTypes = { "authorization_code", "client_credentials" };
            if (!allowedGrantTypes.Contains(context.Result.ValidatedRequest.GrantType) ||
                context.Result.ValidatedRequest.ClientId.StartsWith("organization"))
            {
                return;
            }
            await ValidateAsync(context, context.Result.ValidatedRequest);
        }

        protected async override Task<(User, bool)> ValidateContextAsync(CustomTokenRequestValidationContext context)
        {
            var email = context.Result.ValidatedRequest.Subject?.GetDisplayName()
                ?? context.Result.ValidatedRequest.ClientClaims?.FirstOrDefault(claim => claim.Type == JwtClaimTypes.Email)?.Value;
            var user = string.IsNullOrWhiteSpace(email) ? null : await _userManager.FindByEmailAsync(email);
            return (user, user != null);
        }

        protected override async Task SetSuccessResult(CustomTokenRequestValidationContext context, User user,
            List<Claim> claims, Dictionary<string, object> customResponse)
        {
            context.Result.CustomResponse = customResponse;
            if (claims?.Any() ?? false)
            {
                context.Result.ValidatedRequest.Client.AlwaysSendClientClaims = true;
                context.Result.ValidatedRequest.Client.ClientClaimsPrefix = string.Empty;
                foreach (var claim in claims)
                {
                    context.Result.ValidatedRequest.ClientClaims.Add(claim);
                }
            }

            if (context.Result.CustomResponse == null || user.MasterPassword != null)
            {
                return;
            }

            // KeyConnector responses below

            // Apikey login
            if (context.Result.ValidatedRequest.GrantType == "client_credentials")
            {
                if (user.UsesKeyConnector)
                {
                    // KeyConnectorUrl is configured in the CLI client, we just need to tell the client to use it
                    context.Result.CustomResponse["ApiUseKeyConnector"] = true;
                    context.Result.CustomResponse["ResetMasterPassword"] = false;
                }
                return;
            }

            // SSO login
            var organizationClaim = context.Result.ValidatedRequest.Subject?.FindFirst(c => c.Type == "organizationId");
            if (organizationClaim?.Value != null)
            {
                var organizationId = new Guid(organizationClaim.Value);

                var ssoConfig = await _ssoConfigRepository.GetByOrganizationIdAsync(organizationId);
                var ssoConfigData = ssoConfig.GetData();

                if (ssoConfigData is { KeyConnectorEnabled: true } && !string.IsNullOrEmpty(ssoConfigData.KeyConnectorUrl))
                {
                    context.Result.CustomResponse["KeyConnectorUrl"] = ssoConfigData.KeyConnectorUrl;
                    // Prevent clients redirecting to set-password
                    context.Result.CustomResponse["ResetMasterPassword"] = false;
                }
            }
        }

        protected override void SetTwoFactorResult(CustomTokenRequestValidationContext context,
            Dictionary<string, object> customResponse)
        {
            context.Result.Error = "invalid_grant";
            context.Result.ErrorDescription = "Two factor required.";
            context.Result.IsError = true;
            context.Result.CustomResponse = customResponse;
        }

        protected override void SetSsoResult(CustomTokenRequestValidationContext context,
            Dictionary<string, object> customResponse)
        {
            context.Result.Error = "invalid_grant";
            context.Result.ErrorDescription = "Single Sign on required.";
            context.Result.IsError = true;
            context.Result.CustomResponse = customResponse;
        }

        protected override void SetErrorResult(CustomTokenRequestValidationContext context,
            Dictionary<string, object> customResponse)
        {
            context.Result.Error = "invalid_grant";
            context.Result.IsError = true;
            context.Result.CustomResponse = customResponse;
        }
    }
}
