using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using FrameworkDAL.CustomCode.DrillDown;
using FrameworkDAL.DTO.DrillDown;
using GB5Shared.DTO.Framework.AutoNumber;
using GB5Shared.DTO.Framework.Criteria;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.GenerateAutoNumber;
using GB5Shared.ResponseStandard;
using GB5Shared.Validation;

namespace FrameworkBLL.DrillDown
{
    public class DrillDownBLL : IDrillDownBLL
    {
        private readonly IDrillDownDAL _DrillDownDAL;
        private readonly AutoNumber _AutoNumber;
        private readonly IValidation _Validation;

        public DrillDownBLL(IDrillDownDAL DrillDownDAL, AutoNumber AutoNumber, IValidation Validation)
        {
            _DrillDownDAL = DrillDownDAL;
            _AutoNumber = AutoNumber;
            _Validation = Validation;
        }

        public async Task<string> GetDrillDown(int DrillDownId, LoginDTO LoginDTO)
        {
            try
            {
                return await _DrillDownDAL.GetDrillDown(DrillDownId, LoginDTO);
            }
            catch (Exception)
            {
                throw;
            }
        }

        public async Task<string> SaveDrillDown(DrillDownDTO DrillDownDTO, LoginDTO loginDTO)
        {
            if (DrillDownDTO == null)
                throw new ArgumentNullException(nameof(DrillDownDTO));

            AutoNumberDTO? autoNumberDTO = null;
            try
            {
                await _Validation.NotEmpty(DrillDownDTO.DrillDownCode, nameof(DrillDownDTO.DrillDownCode));
                await _Validation.NotEmpty(DrillDownDTO.DrillDownDescription, nameof(DrillDownDTO.DrillDownDescription));
                DrillDownDTO.DrillDownModifiedById = loginDTO.UserId;
                DrillDownDTO.DrillDownModifiedOn = DateTime.UtcNow;

                int count = 1;
                if (DrillDownDTO.DrillDownId == 0)
                {
                    autoNumberDTO = await _AutoNumber.GetAutoNumber(count, "DRILLDOWN", loginDTO);
                    DrillDownDTO.DrillDownId = autoNumberDTO.StartNumber;

                    DrillDownDTO.DrillDownCreatedById = loginDTO.UserId;
                    DrillDownDTO.DrillDownCreatedOn = DateTime.UtcNow;

                    if (DrillDownDTO.DrillDownDetailArray != null && DrillDownDTO.DrillDownDetailArray.Count > 0)
                    {
                        // Detail IDs get their own AutoNumber reservation — the parent's own
                        // DrillDownId must never be mutated here (it was previously incremented
                        // once per child via `DrillDownDTO.DrillDownId++`, corrupting the parent's
                        // own primary key by +N before it was even saved).
                        var detailAutoNumberDTO = await _AutoNumber.GetAutoNumber(
                            DrillDownDTO.DrillDownDetailArray.Count, "DRILLDOWNDETAIL", loginDTO);
                        int nextDetailId = detailAutoNumberDTO.StartNumber;

                        foreach (var child in DrillDownDTO.DrillDownDetailArray)
                        {
                            child.DrillDownDetailId = nextDetailId++;
                            child.DrillDownId = DrillDownDTO.DrillDownId;
                        }
                    }

                    await _DrillDownDAL.SaveDrillDown(DrillDownDTO, loginDTO);

                    return $"DrillDown saved successfully with DrillDownId {DrillDownDTO.DrillDownId}.";
                }
                else
                {
                    await _DrillDownDAL.UpdateDrillDown(DrillDownDTO, loginDTO);

                    return $"DrillDown updated successfully with DrillDownId {DrillDownDTO.DrillDownId}.";
                }
            }
            catch
            {
                if (autoNumberDTO != null && DrillDownDTO.DrillDownId > 0)
                    await _AutoNumber.RollbackAutoNumber("DRILLDOWN", DrillDownDTO.DrillDownId, loginDTO);

                throw;
            }
        }

        public async Task<Result<string>> DeleteDrillDown(int DrillDownId, LoginDTO LoginDTO)
        {
            try
            {
                return await _DrillDownDAL.DeleteDrillDown(DrillDownId, LoginDTO);
            }
            catch (Exception)
            {
                throw;
            }
        }

        public async Task<string> GetSelectListDrillDown(int FirstNumber, int MaxResult, CriteriaDTO CriteriaDTO, LoginDTO LoginDTO)
        {
            try
            {
                return await _DrillDownDAL.GetSelectListDrillDown(FirstNumber, MaxResult, CriteriaDTO, LoginDTO);
            }
            catch (Exception ex)
            {
                throw new Exception("Error in GetSelectListDrillDown", ex);
            }
        }
    }
}