using CMSMicroservice.Application.Common;
using CMSMicroservice.Application.Common.Exceptions;
using CMSMicroservice.Application.Common.Interfaces;
using CMSMicroservice.Application.Common.Models;
using CMSMicroservice.Domain.Entities;
using CMSMicroservice.Domain.Entities.Payment;
using MediatR;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace CMSMicroservice.Application.WalletCQ.Commands.ChargeDiscountWallet;

public class ChargeDiscountWalletCommandHandler 
    : IRequestHandler<ChargeDiscountWalletCommand, PaymentInitiateResult>
{
    private readonly IApplicationDbContext _context;
    private readonly IPaymentGatewayService _paymentGateway;
    private readonly IConfiguration _configuration;
    private readonly ILogger<ChargeDiscountWalletCommandHandler> _logger;
    private readonly IUserPaymentLock _paymentLock;

    public ChargeDiscountWalletCommandHandler(
        IApplicationDbContext context,
        IPaymentGatewayService paymentGateway,
        IConfiguration configuration,
        ILogger<ChargeDiscountWalletCommandHandler> logger,
        IUserPaymentLock paymentLock)
    {
        _context = context;
        _paymentGateway = paymentGateway;
        _configuration = configuration;
        _logger = logger;
        _paymentLock = paymentLock;
    }

    public Task<PaymentInitiateResult> Handle(
        ChargeDiscountWalletCommand request,
        CancellationToken cancellationToken) =>
        _paymentLock.ExecuteAsync(
            PaymentLockScopes.Initiate(request.UserId),
            PaymentLockStrategy.FailFast,
            ct => HandleCore(request, ct),
            cancellationToken);

    private async Task<PaymentInitiateResult> HandleCore(
        ChargeDiscountWalletCommand request,
        CancellationToken cancellationToken)
    {
        try
        {
            _logger.LogInformation(
                "Charging discount wallet for UserId: {UserId}, Amount: {Amount}",
                request.UserId,
                request.Amount
            );

            // 1. بررسی وجود کاربر
            var user = await _context.Users
                .FirstOrDefaultAsync(u => u.Id == request.UserId, cancellationToken);

            if (user == null)
            {
                _logger.LogWarning("User not found: {UserId}", request.UserId);
                throw new NotFoundException(nameof(User), request.UserId);
            }

            // 2. بررسی وجود کیف پول
            var wallet = await _context.UserWallets
                .FirstOrDefaultAsync(w => w.UserId == request.UserId, cancellationToken);

            if (wallet == null)
            {
                _logger.LogError("Wallet not found for UserId: {UserId}", request.UserId);
                throw new NotFoundException("کیف پول کاربر یافت نشد");
            }

            // 3. ایجاد درخواست پرداخت — callback مستقیم به فرانت‌آفیس
            var frontOfficeBaseUrl = _configuration["FrontOfficeBaseUrl"] ?? "https://localhost:5268";
            var callbackUrl = $"{frontOfficeBaseUrl}/profile/payment-callback?type=discount-wallet";

            var paymentRequest = new PaymentRequest
            {
                Amount = request.Amount,
                UserId = user.Id,
                Mobile = user.Mobile ?? "",
                CallbackUrl = callbackUrl,
                Description = $"شارژ کیف پول تخفیفی - کاربر {user.Id}"
            };

            var paymentResult = await _paymentGateway.InitiatePaymentAsync(paymentRequest);

            if (!paymentResult.IsSuccess)
            {
                _logger.LogError(
                    "Payment gateway failed for UserId {UserId}: {ErrorMessage}",
                    user.Id,
                    paymentResult.ErrorMessage
                );

                throw new Exception($"خطا در ارتباط با درگاه پرداخت: {paymentResult.ErrorMessage}");
            }

            // 4. ثبت PaymentTransaction
            var paymentTx = new PaymentTransaction
            {
                GatewayProvider = _configuration["PaymentProvider"] ?? "zarinpal",
                MerchantId = _configuration["ZarinPal:MerchantId"] ?? "",
                Amount = request.Amount,
                CallbackUrl = callbackUrl,
                Description = $"شارژ کیف پول تخفیفی - کاربر {user.Id}",
                Mobile = user.Mobile,
                UserId = user.Id,
                RequestStatusCode = 100,
                RequestStatusMessage = "Success",
                Authority = paymentResult.RefId,
                PaymentStatus = false
            };
            _context.PaymentTransactions.Add(paymentTx);
            await _context.SaveChangesAsync(cancellationToken);

            _logger.LogInformation(
                "Discount wallet charge initiated. UserId: {UserId}, RefId: {RefId}, PaymentTxId: {PaymentTxId}",
                user.Id,
                paymentResult.RefId,
                paymentTx.Id
            );

            return paymentResult;
        }
        catch (Exception ex)
        {
            _logger.LogError(
                ex,
                "Error in ChargeDiscountWalletCommand for UserId: {UserId}",
                request.UserId
            );
            throw;
        }
    }
}