using BizProcessBLL.Interfaces;
using FastEndpoints;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Framework.ResponseStandard;
using GB5Shared.FastEndPoint;
using static GB5Shared.GB5Constant.Constant;

namespace BizProcessSL.Endpoints.Reports
{
    // Phase 9a -- "Process Traceability Report" PDF, same rendering pipeline/rationale as
    // GetProcessControlCopy.cs. Renders Phase 7's instance-trace result (visited/current/future
    // stages) as a formatted document -- no new data-gathering, a document view of data
    // GetProcessInstanceTrace already computes.
    public class GetProcessTraceabilityReport : BaseEndpoint<GetProcessTraceabilityReport.Parameters, ResponseStandardDTO<object>>
    {
        private readonly IBizProcessBLL _bll;

        public GetProcessTraceabilityReport(IBizProcessBLL bll) => _bll = bll;

        public override void Configure()
        {
            Get("/BizProcess/Reports/GetProcessTraceabilityReport");
            AllowAnonymous();
        }

        public record Parameters(
            [property: FromHeader] string Login,
            [property: QueryParam] int BizProcessVariantId,
            [property: QueryParam] int PivotAllocationId
        );

        protected override string? GetCacheKey(Parameters req, LoginDTO login) => null;

        protected override async Task<ResponseStandardDTO<object>> ExecuteAsync(Parameters req, LoginDTO login, CancellationToken ct)
        {
            try
            {
                var pdfBytes = await _bll.GetProcessTraceabilityReportPdf(req.BizProcessVariantId, req.PivotAllocationId, login, ct).ConfigureAwait(false);

                using var ms = new MemoryStream(pdfBytes);
                await HttpContext.Response.SendStreamAsync(ms, $"ProcessTraceabilityReport_{req.PivotAllocationId}.pdf", ms.Length, "application/pdf", cancellation: ct);

                return null!;
            }
            catch (Exception ex)
            {
                return await GB5Shared.ResponseStandard.Response.CreateExceptionError<string>(ex, CacheKeyLevel.NOT_REQUIRED, login, ex.Message, 500);
            }
        }
    }
}