using FastEndpoints;
using FrameworkBLL.SchedulerTaskGenerator;
using FrameworkDAL.CustomCode.SchedulerTaskGenerator;
using FrameworkDAL.DTO.SchedulerTaskGenerator;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Framework.ResponseStandard;
using GB5Shared.FastEndPoint;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using static GB5Shared.GB5Constant.Constant;

namespace FrameworkSL.Endpoints.SchedulerTaskGenerator
{
    /// <summary>
    /// Returns all scheduler jobs that are due for execution at the current IST time.
    /// Called internally by the scheduler engine to determine what to dispatch next.
    /// </summary>
    public sealed class GetSchedulerTasksEndpoint
        : BaseEndpoint<GetSchedulerTasksEndpoint.GetSchedulerTasksParameters, ResponseStandardDTO<object>>
    {
        private readonly ISchedulerTaskServiceBLL _schedulerService;
        private readonly ILoginContextProvider _loginProvider;

        public GetSchedulerTasksEndpoint(
            ISchedulerTaskServiceBLL schedulerService,
            ILoginContextProvider loginProvider)
        {
            _schedulerService = schedulerService ?? throw new ArgumentNullException(nameof(schedulerService));
            _loginProvider = loginProvider ?? throw new ArgumentNullException(nameof(loginProvider));
        }

        public override void Configure()
        {
            Get("/Scheduler/GetSchedulerTasks");
            AllowAnonymous(); // Internal scheduler call — no user auth required
        }

        public sealed record GetSchedulerTasksParameters(
            [property: FromHeader] string Login
        );

        protected override async Task<ResponseStandardDTO<object>> ExecuteAsync(
            GetSchedulerTasksParameters req,
            LoginDTO loginDTO,
            CancellationToken ct)
        {
            try
            {
                // ✅ Null-safe: guard loginDTO itself before accessing .DatabaseName
                if (string.IsNullOrWhiteSpace(loginDTO?.DatabaseName))
                    loginDTO = _loginProvider.GetLogin();

                // Compute current IST time at the SL layer before passing to BLL
                var nowIst = TimeZoneInfo.ConvertTimeBySystemTimeZoneId(
                    DateTime.UtcNow, "India Standard Time");

                // Load all jobs that are ready to execute at this moment
                var tasks = await _schedulerService.LoadExecutableTasksAsync(
                    loginDTO, nowIst, ct);

                return await GB5Shared.ResponseStandard.Response.CreateSuccessResponse(
                    tasks.ToList() as object,
                    CacheKeyLevel.USER_LEVEL,
                    loginDTO
                );
            }
            catch (Exception ex)
            {
                // ✅ Consistent generic type: <object> matches the declared return type
                return await GB5Shared.ResponseStandard.Response.CreateExceptionError<object>(
                    ex,
                    CacheKeyLevel.USER_LEVEL,
                    loginDTO,
                    ex.Message,
                    500
                );
            }
        }
    }
}