using CMSMicroservice.Domain.Events;
using CMSMicroservice.Domain.Enums;
using CMSMicroservice.Application.DayaLoanCQ.Services;
using Microsoft.Extensions.Logging;

namespace CMSMicroservice.Application.DayaLoanCQ.Commands.CheckDayaLoanStatus;

public class CheckDayaLoanStatusCommandHandler : IRequestHandler<CheckDayaLoanStatusCommand, CheckDayaLoanStatusResponseDto>
{
    private readonly IApplicationDbContext _context;
    private readonly IDayaLoanApiService _dayaApiService;
    private readonly ILogger<CheckDayaLoanStatusCommandHandler> _logger;
    
    /// <summary>
    /// مبلغ وام دایا - 56 میلیون ریال
    /// </summary>
    private const long DAYA_LOAN_AMOUNT = 56_000_000;

    public CheckDayaLoanStatusCommandHandler(
        IApplicationDbContext context,
        IDayaLoanApiService dayaApiService,
        ILogger<CheckDayaLoanStatusCommandHandler> logger)
    {
        _context = context;
        _dayaApiService = dayaApiService;
        _logger = logger;
    }

    public async Task<CheckDayaLoanStatusResponseDto> Handle(CheckDayaLoanStatusCommand request, CancellationToken cancellationToken)
    {
        var results = new List<DayaLoanStatusItem>();
        
        try
        {
            // فراخوانی سرویس دایا (Mock یا Real)
            var dayaResults = await _dayaApiService.CheckLoanStatusAsync(request.NationalCodes, cancellationToken);
            
            foreach (var dayaResult in dayaResults)
            {
                try
                {
                    results.Add(new DayaLoanStatusItem
                    {
                        NationalCode = dayaResult.NationalCode,
                        Status = dayaResult.Status,
                        ContractNumber = dayaResult.ContractNumber,
                        Message = "استعلام موفق"
                    });
                    
                    // ذخیره یا به‌روزرسانی در دیتابیس
                    var existingContract = await _context.DayaLoanContracts
                        .FirstOrDefaultAsync(d => d.NationalCode == dayaResult.NationalCode, cancellationToken);
                    
                    if (existingContract != null)
                    {
                        var previousStatus = existingContract.Status;
                        existingContract.LastCheckDate = DateTime.Now;
                        existingContract.Status = dayaResult.Status;
                        existingContract.ContractNumber = dayaResult.ContractNumber;
                        
                        // بررسی تغییر وضعیت به PendingReceive یا Received
                        // فقط اگر قبلاً پردازش نشده باشد
                        if (!existingContract.IsProcessed && 
                            !string.IsNullOrEmpty(dayaResult.ContractNumber) &&
                            (dayaResult.Status == DayaLoanStatus.PendingReceive || dayaResult.Status == DayaLoanStatus.Received))
                        {
                            await ProcessDayaLoanReceivedAsync(existingContract.UserId, dayaResult.ContractNumber, cancellationToken);
                            existingContract.IsProcessed = true;
                            
                            _logger.LogInformation(
                                "Daya loan processed for User {UserId}, ContractNumber: {ContractNumber}, Amount: {Amount}",
                                existingContract.UserId, dayaResult.ContractNumber, DAYA_LOAN_AMOUNT);
                        }
                    }
                    else
                    {
                        var user = await _context.Users
                            .FirstOrDefaultAsync(u => u.NationalCode == dayaResult.NationalCode, cancellationToken);
                        
                        if (user != null)
                        {
                            var isProcessed = false;
                            
                            // اگر وضعیت PendingReceive یا Received بود و قرارداد دارد، فوری پردازش کن
                            if (!string.IsNullOrEmpty(dayaResult.ContractNumber) &&
                                (dayaResult.Status == DayaLoanStatus.PendingReceive || dayaResult.Status == DayaLoanStatus.Received))
                            {
                                await ProcessDayaLoanReceivedAsync(user.Id, dayaResult.ContractNumber, cancellationToken);
                                isProcessed = true;
                                
                                _logger.LogInformation(
                                    "Daya loan processed for new contract - User {UserId}, ContractNumber: {ContractNumber}, Amount: {Amount}",
                                    user.Id, dayaResult.ContractNumber, DAYA_LOAN_AMOUNT);
                            }
                            
                            var newContract = new DayaLoanContract
                            {
                                UserId = user.Id,
                                NationalCode = dayaResult.NationalCode,
                                Status = dayaResult.Status,
                                ContractNumber = dayaResult.ContractNumber,
                                LastCheckDate = DateTime.Now,
                                IsProcessed = isProcessed
                            };
                            
                            await _context.DayaLoanContracts.AddAsync(newContract, cancellationToken);
                        }
                    }
                    
                    await _context.SaveChangesAsync(cancellationToken);
                }
                catch (Exception ex)
                {
                    _logger.LogError(ex, "Error processing Daya result for {NationalCode}", dayaResult.NationalCode);
                }
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error calling Daya API service");
            
            // در صورت خطا، نتایج خالی برمی‌گردانیم
            foreach (var nationalCode in request.NationalCodes)
            {
                results.Add(new DayaLoanStatusItem
                {
                    NationalCode = nationalCode,
                    Status = DayaLoanStatus.PendingReceive,
                    ContractNumber = null,
                    Message = $"خطا در استعلام: {ex.Message}"
                });
            }
        }
        
        return new CheckDayaLoanStatusResponseDto
        {
            Results = results,
            TotalChecked = request.NationalCodes.Count,
            SuccessCount = results.Count(r => r.ContractNumber != null)
        };
    }
    
    /// <summary>
    /// پردازش دریافت وام دایا برای کاربر
    /// 1. شارژ کیف پول (Balance + DiscountBalance)
    /// 2. ثبت تراکنش
    /// 3. ثبت لاگ کیف پول
    /// 4. به‌روزرسانی وضعیت کاربر
    /// </summary>
    private async Task ProcessDayaLoanReceivedAsync(long userId, string contractNumber, CancellationToken cancellationToken)
    {
        // پیدا کردن کاربر
        var user = await _context.Users
            .FirstOrDefaultAsync(u => u.Id == userId, cancellationToken);
        
        if (user == null)
        {
            _logger.LogWarning("User {UserId} not found for Daya loan processing", userId);
            return;
        }
        
        // بررسی اینکه قبلاً دریافت نکرده باشد
        if (user.HasReceivedDayaCredit)
        {
            _logger.LogWarning("User {UserId} has already received Daya credit", userId);
            return;
        }
        
        // پیدا کردن یا ایجاد کیف پول کاربر
        var wallet = await _context.UserWallets
            .FirstOrDefaultAsync(w => w.UserId == userId, cancellationToken);
        
        if (wallet == null)
        {
            wallet = new UserWallet
            {
                UserId = userId,
                Balance = 0,
                NetworkBalance = 0,
                DiscountBalance = 0
            };
            await _context.UserWallets.AddAsync(wallet, cancellationToken);
            await _context.SaveChangesAsync(cancellationToken);
        }
        
        // 1. شارژ کیف پول - هم موجودی اصلی و هم موجودی تخفیف
        var previousBalance = wallet.Balance;
        var previousDiscountBalance = wallet.DiscountBalance;
        
        wallet.Balance += DAYA_LOAN_AMOUNT;
        wallet.DiscountBalance += DAYA_LOAN_AMOUNT;
        
        // 2. ثبت تراکنش - RefId = شماره قرارداد، Status = 0 (Success)، Type = 2 (DepositExternal1)
        var transaction = new Transaction
        {
            Amount = DAYA_LOAN_AMOUNT,
            Description = $"شارژ کیف پول از وام دایا - قرارداد {contractNumber}",
            PaymentStatus = PaymentStatus.Success, // 0
            PaymentDate = DateTime.Now,
            RefId = contractNumber,
            Type = TransactionType.DepositExternal1 // 2
        };
        
        await _context.Transactions.AddAsync(transaction, cancellationToken);
        await _context.SaveChangesAsync(cancellationToken);
        
        // 3. ثبت لاگ کیف پول با شناسه تراکنش
        var walletLog = new UserWalletChangeLog
        {
            WalletId = wallet.Id,
            CurrentBalance = wallet.Balance,
            ChangeValue = DAYA_LOAN_AMOUNT,
            CurrentNetworkBalance = wallet.NetworkBalance,
            ChangeNerworkValue = 0,
            CurrentDiscountBalance = wallet.DiscountBalance,
            ChangeDiscountValue = DAYA_LOAN_AMOUNT,
            IsIncrease = true,
            RefrenceId = transaction.Id
        };
        
        await _context.UserWalletChangeLogs.AddAsync(walletLog, cancellationToken);
        
        // 4. به‌روزرسانی وضعیت کاربر
        user.HasReceivedDayaCredit = true;
        user.DayaCreditReceivedAt = DateTime.Now;
        user.PackagePurchaseMethod = PackagePurchaseMethod.DayaLoan; // 1
        
        await _context.SaveChangesAsync(cancellationToken);
        
        _logger.LogInformation(
            "Daya loan fully processed for User {UserId}: " +
            "Wallet Balance {PreviousBalance} -> {NewBalance}, " +
            "DiscountBalance {PreviousDiscountBalance} -> {NewDiscountBalance}, " +
            "Transaction Id: {TransactionId}",
            userId, previousBalance, wallet.Balance, 
            previousDiscountBalance, wallet.DiscountBalance, 
            transaction.Id);
    }
}