using System;
using System.ComponentModel.DataAnnotations;
using System.Threading;
using System.Threading.Tasks;
using RecruitmentDAL.DTO.ManpowerBudget;
using GB5Shared.DaprCache;
using GB5Shared.DTO.Framework.AutoNumber;
using GB5Shared.DTO.Framework.Criteria;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.EntityHandler;
using GB5Shared.GenerateAutoNumber;
using GB5Shared.Resource.Response;
using GB5Shared.Telemetry;
using GB5Shared.Validation;
using Microsoft.Extensions.Logging;
using RecruitmentDAL.CustomeCode.ManpowerBudget;
using static GB5Shared.GB5Constant.Constant;

namespace RecruitmentBLL.ManpowerBudget
{
    public class ManpowerBudgetBLL : IManpowerBudgetBLL
    {
        // FISCALQUARTER (TMANPOWERBUDGET, migration
        // 20260905_Recruitment_Phase6_ManpowerBudget_SqlServer): 0=whole-year 1..4=quarter.
        private const byte FISCALQUARTER_ANNUAL = 0;
        private const byte FISCALQUARTER_MAX = 4;

        private readonly IManpowerBudgetDAL _ManpowerBudgetDAL;
        private readonly AutoNumber _AutoNumber;
        private readonly IValidation _Validation;
        private readonly KeyInvalidate _KeyInvalidate;
        private readonly BaseEntityAppService<ManpowerBudgetDTO> _BaseEntityAppService;
        private readonly ILogger<ManpowerBudgetBLL> _Logger;

        public ManpowerBudgetBLL(
            IManpowerBudgetDAL manpowerBudgetDAL,
            AutoNumber autoNumber,
            IValidation validation,
            KeyInvalidate keyInvalidate,
            BaseEntityAppService<ManpowerBudgetDTO> baseEntityAppService,
            ILogger<ManpowerBudgetBLL> logger)
        {
            _ManpowerBudgetDAL = manpowerBudgetDAL;
            _AutoNumber = autoNumber;
            _Validation = validation;
            _KeyInvalidate = keyInvalidate;
            _BaseEntityAppService = baseEntityAppService;
            _Logger = logger;
        }

        public async Task<string> GetManpowerBudget(int ManpowerBudgetId, LoginDTO LoginDTO, CancellationToken ct)
        {
            try
            {
                return await _ManpowerBudgetDAL.GetManpowerBudget(ManpowerBudgetId, LoginDTO, ct)
                    .ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("get-manpowerbudget-failed", ex);
                _Logger.LogError(ex, "GetManpowerBudget failed for ManpowerBudgetId {ManpowerBudgetId}", ManpowerBudgetId);
                throw;
            }
        }

        public async Task<string> SaveManpowerBudget(ManpowerBudgetDTO ManpowerBudgetDTO, LoginDTO LoginDTO, CancellationToken ct)
        {
            if (ManpowerBudgetDTO == null)
                throw new ArgumentNullException(nameof(ManpowerBudgetDTO));

            AutoNumberDTO? autoNumberDTO = null;

            try
            {
                GB5Trace.Step("validate-manpowerbudget", new { ManpowerBudgetDTO.ManpowerBudgetId });

                if (ManpowerBudgetDTO.DepartmentId <= 0)
                {
                    throw new ValidationException(
                        $"{nameof(ManpowerBudgetDTO.DepartmentId)} must reference a valid MDEPARTMENT row.");
                }

                if (ManpowerBudgetDTO.FiscalYear <= 0)
                {
                    throw new ValidationException(
                        $"{nameof(ManpowerBudgetDTO.FiscalYear)} must be a valid year. Received: {ManpowerBudgetDTO.FiscalYear}.");
                }

                if (ManpowerBudgetDTO.FiscalQuarter > FISCALQUARTER_MAX)
                {
                    throw new ValidationException(
                        $"{nameof(ManpowerBudgetDTO.FiscalQuarter)} must be 0 (whole year) or 1-4 (quarter). Received: {ManpowerBudgetDTO.FiscalQuarter}.");
                }

                if (ManpowerBudgetDTO.ApprovedHeadcount < 0)
                {
                    throw new ValidationException(
                        $"{nameof(ManpowerBudgetDTO.ApprovedHeadcount)} cannot be negative.");
                }

                if (ManpowerBudgetDTO.ApprovedBudgetAmount < 0)
                {
                    throw new ValidationException(
                        $"{nameof(ManpowerBudgetDTO.ApprovedBudgetAmount)} cannot be negative.");
                }

                bool isNew = ManpowerBudgetDTO.ManpowerBudgetId == 0;

                // Consumed counters are only ever advanced by JobRequisitionBLL.ApproveJobRequisition's
                // IncrementManpowerBudgetConsumed follow-up call — never accepted from a caller-supplied
                // save payload, so a new budget row always starts at zero consumption and an update to
                // an existing row never lets a caller silently reset/inflate what's already been consumed.
                if (isNew)
                {
                    ManpowerBudgetDTO.ConsumedHeadcount = 0;
                    ManpowerBudgetDTO.ConsumedBudgetAmount = 0;
                }
                else
                {
                    var existingJson = await _ManpowerBudgetDAL.GetManpowerBudget(ManpowerBudgetDTO.ManpowerBudgetId, LoginDTO, ct).ConfigureAwait(false);
                    var existing = Newtonsoft.Json.JsonConvert.DeserializeObject<ManpowerBudgetDTO>(existingJson);
                    ManpowerBudgetDTO.ConsumedHeadcount = existing?.ConsumedHeadcount ?? 0;
                    ManpowerBudgetDTO.ConsumedBudgetAmount = existing?.ConsumedBudgetAmount ?? 0;
                }

                ManpowerBudgetDTO.ModifiedById = LoginDTO.UserId;
                ManpowerBudgetDTO.ModifiedOn = DateTime.UtcNow;
                ManpowerBudgetDTO.TenantId = LoginDTO.ClientId;

                if (isNew)
                {
                    autoNumberDTO = await _AutoNumber.GetNumberAsync(
                        1,
                        "MANPOWERBUDGET",
                        LoginDTO).ConfigureAwait(false);

                    ManpowerBudgetDTO.ManpowerBudgetId = autoNumberDTO.StartNumber;
                    ManpowerBudgetDTO.CreatedById = LoginDTO.UserId;
                    ManpowerBudgetDTO.CreatedOn = DateTime.UtcNow;
                }

                GB5Trace.Step("save-manpowerbudget", new { ManpowerBudgetDTO.ManpowerBudgetId, isNew });

                await _BaseEntityAppService.ExecuteSaveAsync(
                    EntityConstant.OBJECTRECRUITMENTMANPOWERBUDGET,
                    isNew
                        ? EventTypeConstant.SAVERECRUITMENTMANPOWERBUDGETEVENTTYPEID
                        : EventTypeConstant.UPDATERECRUITMENTMANPOWERBUDGETEVENTTYPEID,
                    ManpowerBudgetDTO,
                    LoginDTO,
                    async tx =>
                    {
                        _ = isNew
                            ? await _ManpowerBudgetDAL.SaveManpowerBudget(ManpowerBudgetDTO, LoginDTO, tx, ct).ConfigureAwait(false)
                            : await _ManpowerBudgetDAL.UpdateManpowerBudget(ManpowerBudgetDTO, LoginDTO, tx, ct).ConfigureAwait(false);
                        return ManpowerBudgetDTO.ManpowerBudgetId;
                    },
                    null, -1, -1, null, isNew).ConfigureAwait(false);

                GB5Trace.Step("event-publish", new
                {
                    EventTypeId = isNew
                        ? EventTypeConstant.SAVERECRUITMENTMANPOWERBUDGETEVENTTYPEID
                        : EventTypeConstant.UPDATERECRUITMENTMANPOWERBUDGETEVENTTYPEID
                });

                var cacheKey = new CacheKeyGeneration().KeyGeneration(
                    ManpowerBudgetDTO.ManpowerBudgetId,
                    EntityConstant.OBJECTRECRUITMENTMANPOWERBUDGET,
                    CacheKeyLevel.CLIENT_LEVEL,
                    LoginDTO);

                await _KeyInvalidate.AllInvalidateCache(cacheKey).ConfigureAwait(false);

                _Logger.LogInformation(
                    "ManpowerBudget {ManpowerBudgetId} {Action} by user {UserId}",
                    ManpowerBudgetDTO.ManpowerBudgetId, isNew ? "saved" : "updated", LoginDTO.UserId);

                return isNew
                    ? $"{SuccessResponse.SaveSuccessMessage} {ManpowerBudgetDTO.ManpowerBudgetId}"
                    : $"{SuccessResponse.UpdateSuccessMessage} {ManpowerBudgetDTO.ManpowerBudgetId}";
            }
            catch (ValidationException vex)
            {
                GB5Trace.MarkFailed("save-manpowerbudget-failed", vex);
                if (autoNumberDTO != null && ManpowerBudgetDTO.ManpowerBudgetId > 0)
                    await _AutoNumber.RollbackAutoNumber("MANPOWERBUDGET", ManpowerBudgetDTO.ManpowerBudgetId, LoginDTO).ConfigureAwait(false);

                throw new Exception(vex.Message);
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("save-manpowerbudget-failed", ex);
                _Logger.LogError(ex, "SaveManpowerBudget failed for ManpowerBudgetId {ManpowerBudgetId}", ManpowerBudgetDTO.ManpowerBudgetId);

                if (autoNumberDTO != null && ManpowerBudgetDTO.ManpowerBudgetId > 0)
                {
                    await _AutoNumber.RollbackAutoNumber(
                        "MANPOWERBUDGET",
                        ManpowerBudgetDTO.ManpowerBudgetId,
                        LoginDTO).ConfigureAwait(false);
                }
                throw;
            }
        }

        public async Task<string> GetSelectListManpowerBudget(CriteriaDTO criteriaDTO, LoginDTO LoginDTO, CancellationToken ct)
        {
            try
            {
                return await _ManpowerBudgetDAL.GetSelectListManpowerBudget(criteriaDTO, LoginDTO, ct)
                    .ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("get-selectlist-manpowerbudget-failed", ex);
                _Logger.LogError(ex, "GetSelectListManpowerBudget failed");
                throw;
            }
        }

        public async Task<string> DeleteManpowerBudget(int ManpowerBudgetId, LoginDTO LoginDTO, CancellationToken ct)
        {
            try
            {
                GB5Trace.Step("delete-manpowerbudget", new { ManpowerBudgetId });

                var result = await _ManpowerBudgetDAL.DeleteManpowerBudget(ManpowerBudgetId, LoginDTO, ct)
                    .ConfigureAwait(false);

                var cacheKey = new CacheKeyGeneration().KeyGeneration(
                    ManpowerBudgetId,
                    EntityConstant.OBJECTRECRUITMENTMANPOWERBUDGET,
                    CacheKeyLevel.CLIENT_LEVEL,
                    LoginDTO);

                await _KeyInvalidate.AllInvalidateCache(cacheKey).ConfigureAwait(false);

                _Logger.LogInformation("ManpowerBudget {ManpowerBudgetId} deleted by user {UserId}", ManpowerBudgetId, LoginDTO.UserId);

                return result;
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("delete-manpowerbudget-failed", ex);
                _Logger.LogError(ex, "DeleteManpowerBudget failed for ManpowerBudgetId {ManpowerBudgetId}", ManpowerBudgetId);
                throw;
            }
        }
    }
}