using System.Text.RegularExpressions;
using AnalyticsDAL.CustomCode.Warehouse;
using AnalyticsDAL.DTO.Warehouse;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.Resource.Response;
using GB5Shared.Telemetry;
using GB5Shared.Validation;
using Microsoft.Extensions.Logging;

namespace AnalyticsBLL.Warehouse
{
    public class WarehouseFactDimensionBLL : IWarehouseFactDimensionBLL
    {
        // Identifiers stored in MWAREHOUSEFACTDIMENSION are used at runtime to build SQL JOINs —
        // validate them here so a typo in an admin form fails loudly at save-time, not at query time.
        private static readonly Regex SafeIdentifier = new(@"^[A-Za-z0-9_]+$", RegexOptions.Compiled);

        private readonly IWarehouseFactDimensionDAL         _dal;
        private readonly IValidation                        _validation;
        private readonly ILogger<WarehouseFactDimensionBLL> _logger;

        public WarehouseFactDimensionBLL(
            IWarehouseFactDimensionDAL         dal,
            IValidation                        validation,
            ILogger<WarehouseFactDimensionBLL> logger)
        {
            _dal        = dal;
            _validation = validation;
            _logger     = logger;
        }

        public async Task<string> GetByFactAsync(int factId, LoginDTO login, CancellationToken ct)
        {
            try
            {
                var rows = await _dal.GetByFactAsync(factId, login, ct).ConfigureAwait(false);
                return System.Text.Json.JsonSerializer.Serialize(rows);
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("get-fact-dimensions-failed", ex);
                _logger.LogError(ex, "GetByFact failed for FactId {FactId}", factId);
                throw;
            }
        }

        public async Task<string> SaveAsync(WarehouseFactDimensionDTO dto, LoginDTO login, CancellationToken ct)
        {
            try
            {
                GB5Trace.Step("validate-fact-dimension", new { dto.FactDimensionId, dto.FactId });
                await _validation.NotEmpty(dto.DimensionTable, nameof(dto.DimensionTable)).ConfigureAwait(false);
                await _validation.NotEmpty(dto.FactFkColumn,   nameof(dto.FactFkColumn))  .ConfigureAwait(false);
                await _validation.NotEmpty(dto.DimJoinColumn,  nameof(dto.DimJoinColumn)) .ConfigureAwait(false);

                if (!SafeIdentifier.IsMatch(dto.DimensionTable))
                    throw new ArgumentException($"DimensionTable '{dto.DimensionTable}' is not a valid SQL identifier.");
                if (!SafeIdentifier.IsMatch(dto.FactFkColumn))
                    throw new ArgumentException($"FactFkColumn '{dto.FactFkColumn}' is not a valid SQL identifier.");
                if (!SafeIdentifier.IsMatch(dto.DimJoinColumn))
                    throw new ArgumentException($"DimJoinColumn '{dto.DimJoinColumn}' is not a valid SQL identifier.");
                if (dto.FactId == 0)
                    throw new ArgumentException("FactId is required.");

                var isNew = dto.FactDimensionId == 0;

                if (isNew)
                {
                    GB5Trace.Step("insert-fact-dimension", new { dto.FactId, dto.DimensionTable });
                    var newId = await _dal.InsertAsync(dto, login, ct).ConfigureAwait(false);
                    return $"{SuccessResponse.SaveSuccessMessage} {newId}";
                }

                GB5Trace.Step("update-fact-dimension", new { dto.FactDimensionId });
                await _dal.UpdateAsync(dto, login, ct).ConfigureAwait(false);
                return $"{SuccessResponse.UpdateSuccessMessage} {dto.FactDimensionId}";
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("save-fact-dimension-failed", ex);
                _logger.LogError(ex, "SaveFactDimension failed for FactId {FactId}", dto.FactId);
                throw;
            }
        }

        public async Task<string> DeleteAsync(int factDimensionId, LoginDTO login, CancellationToken ct)
        {
            try
            {
                GB5Trace.Step("delete-fact-dimension", new { factDimensionId });
                await _dal.DeleteAsync(factDimensionId, login, ct).ConfigureAwait(false);
                return SuccessResponse.DeleteSuccessMessage;
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("delete-fact-dimension-failed", ex);
                _logger.LogError(ex, "DeleteFactDimension failed for FactDimensionId {FactDimensionId}", factDimensionId);
                throw;
            }
        }
    }
}