using System;
using System.Threading.Tasks;
using Compliance.Domain.Models;
using Compliance.DTOs;
using Compliance.Infrastructure.Repositories;
using System.Text;

namespace Compliance.Services.ValidationRules
{
    public class TariffValidationRule(IDistributorRepository distributorRepository) : IValidationRule
    {
        private readonly IDistributorRepository _distributorRepository = distributorRepository;
        private const string RULE_NAME = "Tariff Validation";
        private const string TUSD_ERROR = "TUSD amount doesn't match the expected value based on consumption and tariff";
        public int Priority => 1;

        public async Task<ValidationResult> ValidateAsync(
            BillComplianceRequest request,
            DistributorInformation distributorInfo,
            Client clientInfo)
        {
            var tariffInfo = await _distributorRepository.GetTariffInformationAsync(
                request.DistributorName,
                request.Month) ?? throw new InvalidOperationException("Tariff information not found");
            var isValid = true;
            var message = new StringBuilder();

            if (request.TUSDAmount != request.ConsumptionAmount * tariffInfo.TUSDValue)
            {
                isValid = false;
                message.Append(TUSD_ERROR);
            }

            return new ValidationResult
            {
                IsValid = isValid,
                RuleName = RULE_NAME,
                Message = message.ToString()
            };
        }
    }
}