using GB5Shared.DTO.Framework.Login;
using GoodBooks.PAY.PAYBLL.Cashback;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace GoodBooks.PAY.PAYSL.Services
{
    // ─────────────────────────────────────────────────────────────────────────
    //  CashbackPayoutJob
    //
    //  .NET 9 BackgroundService using PeriodicTimer.
    //  Polls TCASHBACKLEDGER every N minutes (default 15) for pending payouts.
    //  Delegates to ICashbackLedgerBLL.ProcessPendingPayoutsAsync which handles:
    //    Mode 1 — CreditNote:    IFinanceIntegrationService.PostCreditNoteAsync
    //    Mode 2 — GatewayPayout: NotImplementedException (Phase 2)
    //    Mode 3 — Wallet:        NotImplementedException (Phase 2)
    //    Mode 4 — LoyaltyPoints: ICustomerLoyaltyBLL.EarnPointsAsync
    // ─────────────────────────────────────────────────────────────────────────
    public sealed class CashbackPayoutJob : BackgroundService
    {
        private readonly IServiceScopeFactory          _scopeFactory;
        private readonly IConfiguration                _config;
        private readonly ILogger<CashbackPayoutJob>   _logger;

        public CashbackPayoutJob(
            IServiceScopeFactory        scopeFactory,
            IConfiguration              config,
            ILogger<CashbackPayoutJob>  logger)
        {
            _scopeFactory = scopeFactory;
            _config       = config;
            _logger       = logger;
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            int intervalMins = _config.GetValue<int>("PayJobs:CashbackPayoutIntervalMinutes", 15);

            _logger.LogInformation(
                "CashbackPayoutJob starting — interval {IntervalMins}m", intervalMins);

            using var timer = new PeriodicTimer(TimeSpan.FromMinutes(intervalMins));

            while (await timer.WaitForNextTickAsync(stoppingToken))
            {
                _logger.LogInformation("CashbackPayoutJob tick at {UtcNow:u}", DateTime.UtcNow);

                try
                {
                    using var scope = _scopeFactory.CreateScope();
                    var bll = scope.ServiceProvider.GetRequiredService<ICashbackLedgerBLL>();

                    var systemLogin = BuildSystemLogin();
                    await bll.ProcessPendingPayoutsAsync(systemLogin, stoppingToken).ConfigureAwait(false);

                    _logger.LogInformation("CashbackPayoutJob cycle completed at {UtcNow:u}", DateTime.UtcNow);
                }
                catch (Exception ex) when (ex is not OperationCanceledException)
                {
                    _logger.LogError(ex, "CashbackPayoutJob cycle failed.");
                    // Continue — next tick will retry
                }
            }
        }

        private LoginDTO BuildSystemLogin() => new()
        {
            ClientId     = _config.GetValue<int>("PayJobs:SystemTenantId", -1),
            DatabaseName = _config["PayJobs:SystemDatabaseName"] ?? "GoodBooks_Main",
            UserId       = -1
        };
    }
}