using System.IO;
using FastEndpoints;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Framework.ResponseStandard;
using GB5Shared.FastEndPoint;
using WiBLL.WiScanCode;
using WiDAL.DTOs;
using static GB5Shared.GB5Constant.Constant;

namespace WiSL.EndPoints.WiScanCode
{
    // Tenant-scoped — mirrors TMSSL's DownloadCertificate.cs pattern (BaseEndpoint +
    // HttpContext.Response.SendStreamAsync + return null!) rather than an anonymous
    // byte-stream endpoint, since generating a code requires login.ClientId to check
    // the target entity actually belongs to this tenant before handing out a scannable code.
    public class GenerateScanCode : BaseEndpoint<GenerateScanCode.Parameters, ResponseStandardDTO<object>>
    {
        private readonly IWiScanCodeBLL _bll;

        public GenerateScanCode(IWiScanCodeBLL bll)
        {
            _bll = bll;
        }

        public override void Configure()
        {
            Get("/Wi/GenerateScanCode");
            AllowAnonymous();
        }

        public record Parameters(
            [property: FromHeader] string Login,
            [property: QueryParam] ScanCodeType CodeType,
            [property: QueryParam] int EntityId,
            [property: QueryParam] int? PixelsPerModule
        );

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

        protected override async Task<ResponseStandardDTO<object>> ExecuteAsync(
            Parameters req, LoginDTO login, CancellationToken ct)
        {
            try
            {
                var png = await _bll.GenerateScanCode(req.CodeType, req.EntityId, req.PixelsPerModule ?? 20, login, ct)
                    .ConfigureAwait(false);

                using var ms = new MemoryStream(png);
                await HttpContext.Response.SendStreamAsync(ms, $"{req.CodeType}_{req.EntityId}.png", ms.Length, "image/png", cancellation: ct);

                return null!;
            }
            catch (InvalidOperationException ex)
            {
                return await GB5Shared.ResponseStandard.Response.CreateExceptionError<string>(ex, CacheKeyLevel.NOT_REQUIRED, login, ex.Message, 404);
            }
            catch (Exception ex)
            {
                return await GB5Shared.ResponseStandard.Response.CreateExceptionError<string>(ex, CacheKeyLevel.NOT_REQUIRED, login, ex.Message, 500);
            }
        }
    }
}