using GB5Shared.DTO.Framework.AutoNumber;
using GB5Shared.DTO.Framework.Criteria;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.GenerateAutoNumber;
using GB5Shared.Resource.Response;
using GB5Shared.Validation;
using System.ComponentModel.DataAnnotations;
using TMSDAL.CustomCode.PaperSection;
using TMSDAL.DTO.Assessment;

namespace TMSBLL.PaperSection
{
    public class PaperSectionBLL : IPaperSectionBLL
    {
        private readonly IPaperSectionDAL _PaperSectionDAL;
        private readonly AutoNumber _AutoNumber;
        private readonly IValidation _Validation;

        public PaperSectionBLL(
            IPaperSectionDAL paperSectionDAL,
            AutoNumber autoNumber,
            IValidation validation)
        {
            _PaperSectionDAL = paperSectionDAL;
            _AutoNumber = autoNumber;
            _Validation = validation;
        }


        // ═══════════════════════════════════════════════════════════════════════
        // GET
        // ═══════════════════════════════════════════════════════════════════════

        public async Task<string> GetPaperSection(int paperSectionId, LoginDTO loginDTO)
        {
            try
            {
                return await _PaperSectionDAL.GetPaperSection(paperSectionId, loginDTO);
            }
            catch (Exception) { throw; }
        }

        public async Task<string> GetPaperSectionList(int assessmentPaperId, LoginDTO loginDTO)
        {
            try
            {
                return await _PaperSectionDAL.GetPaperSectionList(assessmentPaperId, loginDTO);
            }
            catch (Exception) { throw; }
        }

        public async Task<string> GetSelectListPaperSection(CriteriaDTO criteriaDTO, LoginDTO loginDTO)
            => await _PaperSectionDAL.GetSelectListPaperSection(criteriaDTO, loginDTO);


        // ═══════════════════════════════════════════════════════════════════════
        // SAVE / UPDATE
        // ═══════════════════════════════════════════════════════════════════════

        public async Task<string> SavePaperSection(PaperSectionDTO dto, LoginDTO loginDTO)
        {
            if (dto == null) throw new ArgumentNullException(nameof(dto));
            AutoNumberDTO? autoNumberDTO = null;

            try
            {
                // ── Validations ──────────────────────────────────────────────
                await _Validation.NotEmpty(dto.SectionTitle, nameof(dto.SectionTitle));

                string message;

                if (dto.PaperSectionId == 0)
                {
                    // ── INSERT ───────────────────────────────────────────────
                    autoNumberDTO = await _AutoNumber.GetAutoNumber(1, "PAPERSECTION", loginDTO);
                    dto.PaperSectionId = autoNumberDTO.StartNumber;

                    await _PaperSectionDAL.SavePaperSection(dto, loginDTO);
                    message = string.Format(SuccessResponse.SaveSuccessWithName, dto.SectionTitle);
                }
                else
                {
                    // ── UPDATE ───────────────────────────────────────────────
                    await _PaperSectionDAL.UpdatePaperSection(dto, loginDTO);
                    message = string.Format(SuccessResponse.UpdateSuccessWithName, dto.SectionTitle);
                }

                return message;
            }
            catch (ValidationException vex)
            {
                throw new Exception(vex.Message);
            }
            catch (Exception)
            {
                // ── Rollback AutoNumber on failure ───────────────────────────
                if (autoNumberDTO != null && dto.PaperSectionId > 0)
                    await _AutoNumber.RollbackAutoNumber("PAPERSECTION", dto.PaperSectionId, loginDTO);
                throw;
            }
        }


        // ═══════════════════════════════════════════════════════════════════════
        // DELETE
        // ═══════════════════════════════════════════════════════════════════════

        public async Task<string> DeletePaperSection(int paperSectionId, LoginDTO loginDTO)
        {
            try
            {
                return await _PaperSectionDAL.DeletePaperSection(paperSectionId, loginDTO);
            }
            catch (Exception) { throw; }
        }

        public async Task<string> DeletePaperSectionsByPaper(int assessmentPaperId, LoginDTO loginDTO)
        {
            try
            {
                int rows = await _PaperSectionDAL.DeletePaperSectionsByPaper(assessmentPaperId, loginDTO);
                return rows > 0
                    ? $"{SuccessResponse.DeleteSuccessMessage} {rows} section(s) removed."
                    : ErrorResponse.DeleteNotFoundMessage;
            }
            catch (Exception) { throw; }
        }
    }
}