using System.Linq;
using FastEndpoints;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Framework.ResponseStandard;
using GB5Shared.FastEndPoint;
using RecruitmentBLL.CandidatePortal;
using RecruitmentSL.Common;
using ErrorResponse = GB5Shared.Resource.Response.ErrorResponse;
using static GB5Shared.GB5Constant.Constant;

namespace RecruitmentSL.EndPoints.CandidatePortal
{
    // CandidatePortal-scheme-protected. ObjectId (CandidateId) is always resolved from the
    // verified JWT claims server-side (CandidatePortalCallerContext) — never client-supplied —
    // so a candidate can never tag an attachment against another candidate's record. Tagged with
    // EntityConstant.OBJECTRECRUITMENTCANDIDATEDOC via ICandidatePortalBLL.UploadDocumentAsync
    // (GB5Shared.Attachment.IAttachmentUploadService).
    public class UploadDocument : BaseEndpoint<UploadDocument.Params, ResponseStandardDTO<object>>
    {
        private const string CandidatePortalScheme = "CandidatePortal";

        private readonly ICandidatePortalBLL _BLL;

        public UploadDocument(ICandidatePortalBLL bll) => _BLL = bll;

        public record Params(
            [property: FromHeader] string  Login,
            [property: QueryParam] string? Remarks
        );

        public override void Configure()
        {
            Post("/CandidatePortal/UploadDocument");
            AllowFileUploads();
            AuthSchemes(CandidatePortalScheme);
        }

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

        protected override async Task<ResponseStandardDTO<object>> ExecuteAsync(
            Params req, LoginDTO login, CancellationToken ct)
        {
            var caller = CandidatePortalCallerContext.FromClaims(HttpContext.User.Claims);
            if (caller.CandidateId <= 0)
                return await GB5Shared.ResponseStandard.Response.CreateErrorResponse<object>(
                    ErrorResponse.AccessDeniedMessage, CacheKeyLevel.NOT_REQUIRED, login, statusCode: 403);

            try
            {
                var file = HttpContext.Request.Form.Files.FirstOrDefault();
                if (file is null || file.Length == 0)
                    throw new ArgumentException("No file provided or file is empty.");

                await using var stream = file.OpenReadStream();

                var result = await _BLL.UploadDocumentAsync(
                    caller.CandidateId, stream, file.FileName, file.ContentType, req.Remarks, login, ct)
                    .ConfigureAwait(false);

                return await GB5Shared.ResponseStandard.Response.CreateSuccessResponse(
                    result, CacheKeyLevel.NOT_REQUIRED, login);
            }
            catch (Exception ex)
            {
                return await GB5Shared.ResponseStandard.Response.CreateExceptionError<string>(
                    ex, CacheKeyLevel.NOT_REQUIRED, login, ex.Message, 400);
            }
        }
    }
}