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

namespace RecruitmentBLL.Reports.CandidateSourceQuality
{
    // Phase 5 analytics — source-quality report. Whole-tenant aggregate grouped by
    // Candidate.Source; CriteriaDTO is accepted for API-shape consistency with the other two
    // reports (and future SearchKeyword/date-range filters) but is not currently used to narrow
    // this report — see CandidateSourceQualityDTO's doc comment for the bounded row-count reason.
    public class CandidateSourceQualityBLL : ICandidateSourceQualityBLL
    {
        private const int DEFAULT_MAX_RESULT_CAP = 500;

        private readonly ICandidateSourceQualityDAL _dal;

        public CandidateSourceQualityBLL(ICandidateSourceQualityDAL dal)
        {
            _dal = dal;
        }

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

                GB5Trace.Step("query-candidate-source-quality", new { firstNumber, cappedMaxResult });
                return await _dal.GetCandidateSourceQuality(firstNumber, cappedMaxResult, login, ct).ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("candidate-source-quality-failed", ex);
                throw;
            }
        }

        public async IAsyncEnumerable<CandidateSourceQualityDTO> GetCandidateSourceQualityStream(
            int firstNumber, int maxResult, CriteriaDTO? criteriaDTO, LoginDTO login,
            [EnumeratorCancellation] CancellationToken ct)
        {
            GB5Trace.Step("stream-candidate-source-quality", new { firstNumber, maxResult });

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