using System;
using System.Threading.Tasks;
using AccountsDAL.CustomCode.AccountReports;
using AccountsDAL.DTO.AccountsReports;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.Resource.Response;

namespace AccountsBLL.AccountReports
{
    // New backend enforcement for the "avoid a mistaken open-filter report run" gap identified during
    // migration planning: today (both in legacy and in GB5) MROLEVSMENU's day/record limits and
    // MUSERACCESSRIGHTS.NOOFREADPERIOD are only enforced by the frontend — a REST caller hitting these
    // endpoints directly bypasses them entirely. This closes that gap for the AccountReports family.
    //
    // Menu IDs for these reports are not yet minted in MMENU (no gb5-meta/uscdevsys access this
    // session) — callers pass in a menuId; if no MROLEVSMENU row exists for (RoleId, menuId) this
    // enforces nothing for the day/record-limit check (fail-open) rather than blocking the report
    // outright on an unresolved placeholder id. Replace the placeholder menuId constants in
    // AccountRegisterReportBLL/AccountRegisterSummaryBLL once the real menu entries exist.
    //
    // NOOFREADPERIOD's exact semantics are inferred, not independently verified: the only concrete
    // precedent found (UserAccessRightsDAL.GetUserAccessRightsOnUser, for the sibling NOOFPERIOD
    // column) treats the value 1 as "restrict to the current/latest period only" rather than a literal
    // "N periods back" count. This enforces the same interpretation for report reads. If this ever
    // needs to be a genuine multi-period lookback count, revisit here.
    public class AccountReportAccessControlBLL : IAccountReportAccessControlBLL
    {
        private readonly IAccountReportAccessControlDAL _dal;

        public AccountReportAccessControlBLL(IAccountReportAccessControlDAL dal)
        {
            _dal = dal;
        }

        public async Task EnforceAsync(AccountReportCriteria criteria, int maxResult, int menuId, LoginDTO loginDTO)
        {
            if (criteria.PeriodFromDate == default || criteria.PeriodToDate == default)
                throw new InvalidOperationException(ErrorResponse.PeriodRangeRequiredMessage);

            if (criteria.PeriodFromDate > criteria.PeriodToDate)
                throw new InvalidOperationException(ErrorResponse.PeriodRangeInvertedMessage);

            var limits = await _dal.GetReportAccessLimits(loginDTO.RoleId, menuId, loginDTO).ConfigureAwait(false);
            if (limits != null)
            {
                var requestedDays = (criteria.PeriodToDate.Date - criteria.PeriodFromDate.Date).TotalDays + 1;
                if (limits.DaysLimit > 0 && requestedDays > limits.DaysLimit)
                    throw new InvalidOperationException(ErrorResponse.DaysLimitExceededMessage);

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

            var noOfReadPeriod = await _dal.GetNoOfReadPeriodForUser(loginDTO.UserId, loginDTO).ConfigureAwait(false);
            if (noOfReadPeriod == 1)
            {
                var workPeriod = await _dal.GetPeriodDateRange(loginDTO.WorkPeriodId, loginDTO).ConfigureAwait(false);
                if (workPeriod != null && criteria.PeriodFromDate.Date < workPeriod.FromDate.Date)
                    throw new InvalidOperationException(ErrorResponse.PeriodTooEarlyMessage);
            }
        }

        public async Task EnforceForAsOnDateAsync(AccountReportCriteria criteria, int maxResult, int menuId, LoginDTO loginDTO)
        {
            var limits = await _dal.GetReportAccessLimits(loginDTO.RoleId, menuId, loginDTO).ConfigureAwait(false);
            if (limits != null && limits.RecordsLimit > 0 && maxResult > limits.RecordsLimit)
                throw new InvalidOperationException(ErrorResponse.RecordsLimitExceededMessage);

            var noOfReadPeriod = await _dal.GetNoOfReadPeriodForUser(loginDTO.UserId, loginDTO).ConfigureAwait(false);
            if (noOfReadPeriod == 1)
            {
                var workPeriod = await _dal.GetPeriodDateRange(loginDTO.WorkPeriodId, loginDTO).ConfigureAwait(false);
                if (workPeriod != null && criteria.AsOnDate.Date < workPeriod.FromDate.Date)
                    throw new InvalidOperationException(ErrorResponse.PeriodTooEarlyMessage);
            }
        }
    }
}