using System;
using System.Threading;
using System.Threading.Tasks;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.Resource.Response;
using TMSDAL.CustomCode.Reports;
using TMSDAL.DTO.Reports;

namespace TMSBLL.Reports
{
    // Backend enforcement for MROLEVSMENU's day/record limits, mirroring
    // AccountsBLL.AccountReports.AccountReportAccessControlBLL -- a REST caller hitting a TMS report
    // endpoint directly must not be able to bypass limits the frontend would otherwise enforce.
    // Lighter than the Accounts version: most TMS reports are point-in-time registers, not
    // period-ledger reports, so a date range is optional here (DaysLimit is only checked when the
    // caller actually supplied one), and there is no NOOFREADPERIOD equivalent (that concept is
    // specific to Accounts' financial-period model).
    public class TmsReportAccessControlBLL : ITmsReportAccessControlBLL
    {
        private readonly ITmsReportAccessControlDAL _dal;

        public TmsReportAccessControlBLL(ITmsReportAccessControlDAL dal)
        {
            _dal = dal;
        }

        public async Task EnforceAsync(TmsReportCriteria criteria, int maxResult, int menuId, LoginDTO loginDTO, CancellationToken ct)
        {
            var limits = await _dal.GetReportAccessLimits(loginDTO.RoleId, menuId, loginDTO, ct).ConfigureAwait(false);
            if (limits == null)
                return;

            if (limits.DaysLimit > 0 && criteria.FromDate.HasValue && criteria.ToDate.HasValue)
            {
                var requestedDays = (criteria.ToDate.Value.Date - criteria.FromDate.Value.Date).TotalDays + 1;
                if (requestedDays > limits.DaysLimit)
                    throw new InvalidOperationException(ErrorResponse.DaysLimitExceededMessage);
            }

            if (limits.RecordsLimit > 0 && maxResult > limits.RecordsLimit)
                throw new InvalidOperationException(ErrorResponse.RecordsLimitExceededMessage);
        }
    }
}