using System.Runtime.CompilerServices;
using GB5Shared.DTO.Framework.Criteria;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.QueryExecutor;
using GB5Shared.Telemetry;
using RecruitmentDAL.CustomeCode.Reports.JobAdSpendPerformance;
using RecruitmentDAL.DTO.Reports;

namespace RecruitmentBLL.Reports.JobAdSpendPerformance
{
    // Phase 6 analytics — job-ad spend performance report. CriteriaDTO.Id doubles as an optional
    // JobRequisitionId filter, same "0/<=0 = unset" sentinel convention as
    // ApplicationCycleTimeBLL.ResolveJobRequisitionIdFilter; a caller who wants every requisition
    // for the tenant simply omits it / leaves it 0.
    public class JobAdSpendPerformanceBLL : IJobAdSpendPerformanceBLL
    {
        private const int DEFAULT_MAX_RESULT_CAP = 500;

        private readonly IJobAdSpendPerformanceDAL _dal;

        public JobAdSpendPerformanceBLL(IJobAdSpendPerformanceDAL dal)
        {
            _dal = dal;
        }

        public async Task<PagedResult<JobAdSpendPerformanceDTO>> GetJobAdSpendPerformance(
            int firstNumber, int maxResult, CriteriaDTO? criteriaDTO, LoginDTO login, CancellationToken ct)
        {
            try
            {
                var jobRequisitionId = ResolveJobRequisitionIdFilter(criteriaDTO);
                var cappedMaxResult = maxResult > 0 ? Math.Min(maxResult, DEFAULT_MAX_RESULT_CAP) : DEFAULT_MAX_RESULT_CAP;

                GB5Trace.Step("query-jobadspend-performance", new { firstNumber, cappedMaxResult, jobRequisitionId });
                return await _dal.GetJobAdSpendPerformance(firstNumber, cappedMaxResult, jobRequisitionId, login, ct).ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("jobadspend-performance-failed", ex);
                throw;
            }
        }

        public async IAsyncEnumerable<JobAdSpendPerformanceDTO> GetJobAdSpendPerformanceStream(
            int firstNumber, int maxResult, CriteriaDTO? criteriaDTO, LoginDTO login,
            [EnumeratorCancellation] CancellationToken ct)
        {
            var jobRequisitionId = ResolveJobRequisitionIdFilter(criteriaDTO);
            GB5Trace.Step("stream-jobadspend-performance", new { firstNumber, maxResult, jobRequisitionId });

            await foreach (var row in _dal.GetJobAdSpendPerformanceStream(jobRequisitionId, login, ct).ConfigureAwait(false))
                yield return row;
        }

        private static int? ResolveJobRequisitionIdFilter(CriteriaDTO? criteriaDTO)
            => criteriaDTO != null && criteriaDTO.Id > 0 ? criteriaDTO.Id : null;
    }
}