using Fitness_core_BE.Exceptions;
using Fitness_core_BE.Helpers;
using Fitness_core_BE.Infra.UoW;
using Fitness_core_BE.Interfaces;
using Fitness_core_BE.DTOs.PaymentsEnablement;
using Fitness_core_BE.Interfaces.Services;
using Fitness_core_BE.Models.Enums;

namespace Fitness_core_BE.Services
{
    public class PayoutKycReviewService : IPayoutKycReviewService
    {
        private readonly IPaymentsEnablementRepository _paymentsRepository;
        private readonly UserRoleHelper _userRoleHelper;
        private readonly IUnitOfWork _uow;

        public PayoutKycReviewService(IPaymentsEnablementRepository paymentsRepository, UserRoleHelper userRoleHelper, IUnitOfWork uow)
        {
            _paymentsRepository = paymentsRepository;
            _userRoleHelper = userRoleHelper;
            _uow = uow;
        }

        public async Task<List<ClientPayoutKycDto>> ListAsync(string? status)
        {
            var (items, _) = await _paymentsRepository.ListKycAsync(null);
            var latestPerClient = items
                .GroupBy(item => item.FKClientId)
                .Select(group => group
                    .OrderByDescending(item => item.SubmittedAt)
                    .ThenByDescending(item => item.Id)
                    .First());

            if (!string.IsNullOrWhiteSpace(status))
            {
                if (!Enum.TryParse<KycStatus>(status, true, out var parsedStatus))
                    throw new BadRequestException($"Unknown KYC status '{status}'.");
                latestPerClient = latestPerClient
                    .Where(item => item.KycStatus == parsedStatus);
            }

            return latestPerClient
                .OrderByDescending(item => item.SubmittedAt)
                .Select(ToDto)
                .ToList();
        }

        public async Task<ClientPayoutKycDto> GetByClientIdAsync(Guid clientId)
        {
            var kyc = await _paymentsRepository.GetKycByClientIdAsync(clientId)
                ?? throw new NotFoundException("No KYC submission found for this client.");
            return ToDto(kyc);
        }

        public async Task<ClientPayoutKycDto> ReviewAsync(Guid clientId, ReviewPayoutKycRequest request, HttpContext httpContext)
        {
            var kyc = await _paymentsRepository.GetKycForUpdateAsync(clientId)
                ?? throw new NotFoundException("No KYC submission found for this client.");

            if (!Enum.TryParse<KycStatus>(request.Status, true, out var newStatus))
                throw new BadRequestException($"Unknown KYC status '{request.Status}'.");
            if (newStatus is not KycStatus.Approved and not KycStatus.Rejected)
                throw new BadRequestException("KYC can only be approved or rejected.");
            if (kyc.KycStatus != KycStatus.Pending)
                throw new BadRequestException("Only pending KYC submissions can be reviewed.");
            if (newStatus == KycStatus.Rejected && string.IsNullOrWhiteSpace(request.Reason))
                throw new BadRequestException("A rejection reason is required.");

            var adminUserId = DataExtractor.GetUserIdFromContext(httpContext);
            var adminId = await _userRoleHelper.GetAdminId(adminUserId)
                ?? throw new ForbiddenException("Only admins may review payout KYC.");

            await _uow.BeginAsync();
            try
            {
                kyc.KycStatus = newStatus;
                kyc.ReviewedAt = DateTime.UtcNow;
                kyc.ReviewedByAdminId = adminId;
                kyc.RejectionReason = newStatus == KycStatus.Rejected
                    ? request.Reason!.Trim()
                    : null;

                await _uow.CommitAsync();
                return ToDto(kyc);
            }
            catch
            {
                await _uow.RollbackAsync();
                throw;
            }
        }

        // NIC fields used to come from the multi-gym onboarding wizard's OwnerActivation record
        // (collected during signup); that flow no longer exists for a single already-real club,
        // so these are always null here now. If gateway KYC needs NIC info going forward, collect
        // it directly on the KYC submission instead of reintroducing that dependency.
        private static ClientPayoutKycDto ToDto(Models.ClientPayoutKyc kyc)
        {
            return new ClientPayoutKycDto(
                kyc.Id,
                kyc.FKClientId,
                kyc.Client?.ClientName,
                kyc.SelectedGatewayId,
                kyc.SelectedGatewayName,
                kyc.KycStatus.ToString(),
                kyc.SubmittedAt,
                kyc.ReviewedAt,
                kyc.RejectionReason,
                null,
                null,
                null);
        }
    }
}