using GB5Shared.DTO.Framework.Login;
using GB5Shared.EntityHandler;
using GB5Shared.QueryExecutor;
using GB5Shared.Resource.Response;
using PIEDAL.CustomCode.Proposal;
using PIEDAL.DTO.Proposal;
using static GB5Shared.GB5Constant.Constant;

namespace PIEBLL.Proposal;

public class PIEProposalBLL : IPIEProposalBLL
{
    private readonly IPIEProposalDAL                              _PIEProposalDAL;
    private readonly IQueryExecutor                               _QueryExecutor;
    private readonly BaseEntityAppService<PIELearningProposalDTO> _BaseEntityAppService;

    public PIEProposalBLL(
        IPIEProposalDAL pieProposalDAL,
        IQueryExecutor queryExecutor,
        BaseEntityAppService<PIELearningProposalDTO> baseEntityAppService)
    {
        _PIEProposalDAL       = pieProposalDAL;
        _QueryExecutor        = queryExecutor;
        _BaseEntityAppService = baseEntityAppService;
    }

    // ── Read ──────────────────────────────────────────────────────────────────

    public async Task<PIELearningProposalDTO?> GetPIEProposalAsync(
        Guid proposalId, LoginDTO login, CancellationToken ct)
        => await _PIEProposalDAL.GetPIEProposalAsync(proposalId, login, ct).ConfigureAwait(false);

    // ── Writes ────────────────────────────────────────────────────────────────

    public async Task<string> CreatePIEProposalAsync(
        PIELearningProposalDTO dto, LoginDTO login, CancellationToken ct)
    {
        if (dto is null) throw new ArgumentNullException(nameof(dto));

        if (dto.ProposalType is not (1 or 2 or 3))
            throw new ArgumentException("ProposalType must be 1 (AEO), 2 (Manual), or 3 (Scheduled).");
        if (string.IsNullOrWhiteSpace(dto.ProposalDescription))
            throw new ArgumentException("ProposalDescription is required.");

        if (dto.ProposalId == Guid.Empty)
            dto.ProposalId = Guid.NewGuid();

        var Trans = await _QueryExecutor.BeginTransactionAsync(login).ConfigureAwait(false);
        try
        {
            await _BaseEntityAppService.ExecuteSaveAsync(
                EntityConstant.OBJECTPIEPROPOSAL,
                EventTypeConstant.SAVEPIEPROPOSALEVENTTYPEID,
                dto, login,
                async tx =>
                {
                    await _PIEProposalDAL.InsertPIEProposalAsync(dto, login, tx, ct);
                    return 0; // PIEProposal uses a Guid PK — no int object ID to report back
                },
                null,
                BIZTRANSACTIONCLASSCONSTANT.PIEPROPOSAL,
                BizTransactionConstant.PIEPROPOSAL,
                Trans).ConfigureAwait(false);

            await _QueryExecutor.CommitAsync(Trans).ConfigureAwait(false);

            return SuccessResponse.SaveSuccess;
        }
        catch (Exception ex)
        {
            GB5Shared.Telemetry.GB5Trace.MarkFailed("create-pie-proposal-failed", ex);
            await _QueryExecutor.RollbackAsync(Trans).ConfigureAwait(false);
            throw;
        }
    }

    public async Task<string> ReviewPIEProposalAsync(
        PIEReviewProposalDTO dto, LoginDTO login, CancellationToken ct)
    {
        if (dto is null) throw new ArgumentNullException(nameof(dto));

        // Status 2=Approved 3=Rejected 4=Deferred
        if (dto.Status is not (2 or 3 or 4))
            throw new ArgumentException("Review status must be 2 (Approved), 3 (Rejected), or 4 (Deferred).");

        // Fetch to confirm it still exists and is pending (status check is in QB)
        var existing = await _PIEProposalDAL.GetPIEProposalAsync(dto.ProposalId, login, ct).ConfigureAwait(false);
        if (existing is null)
            throw new InvalidOperationException("Learning proposal not found.");

        if (existing.Status != 1)
            throw new InvalidOperationException(
                "Only Pending proposals (status=1) can be reviewed.");

        var Trans = await _QueryExecutor.BeginTransactionAsync(login).ConfigureAwait(false);
        try
        {
            await _BaseEntityAppService.ExecuteSaveAsync(
                EntityConstant.OBJECTPIEPROPOSAL,
                EventTypeConstant.REVIEWPIEPROPOSALEVENTTYPEID,
                new PIELearningProposalDTO { ProposalId = dto.ProposalId },
                login,
                async tx => { await _PIEProposalDAL.ReviewPIEProposalAsync(
                    dto, login.UserId, login, tx, ct); return 0; },
                null,
                BIZTRANSACTIONCLASSCONSTANT.PIEPROPOSAL,
                BizTransactionConstant.PIEPROPOSAL,
                Trans).ConfigureAwait(false);

            await _QueryExecutor.CommitAsync(Trans).ConfigureAwait(false);

            return SuccessResponse.UpdateSuccess;
        }
        catch (Exception ex)
        {
            GB5Shared.Telemetry.GB5Trace.MarkFailed("review-pie-proposal-failed", ex);
            await _QueryExecutor.RollbackAsync(Trans).ConfigureAwait(false);
            throw;
        }
    }

    public async Task<string> DeletePIEProposalAsync(
        Guid proposalId, LoginDTO login, CancellationToken ct)
    {
        var Trans = await _QueryExecutor.BeginTransactionAsync(login).ConfigureAwait(false);
        try
        {
            await _BaseEntityAppService.ExecuteSaveAsync(
                EntityConstant.OBJECTPIEPROPOSAL,
                EventTypeConstant.SAVEPIEPROPOSALEVENTTYPEID,
                new PIELearningProposalDTO { ProposalId = proposalId },
                login,
                async tx => { await _PIEProposalDAL.DeletePIEProposalAsync(proposalId, login, tx, ct); return 0; },
                null,
                BIZTRANSACTIONCLASSCONSTANT.PIEPROPOSAL,
                BizTransactionConstant.PIEPROPOSAL,
                Trans).ConfigureAwait(false);

            await _QueryExecutor.CommitAsync(Trans).ConfigureAwait(false);

            return SuccessResponse.DeleteSuccessMessage;
        }
        catch (Exception ex)
        {
            GB5Shared.Telemetry.GB5Trace.MarkFailed("delete-pie-proposal-failed", ex);
            await _QueryExecutor.RollbackAsync(Trans).ConfigureAwait(false);
            throw;
        }
    }
}