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 TaxValidationRule(IDistributorRepository distributorRepository) : IValidationRule
    {
        private readonly IDistributorRepository _distributorRepository = distributorRepository;
        private const string RULE_NAME = "Tax Validation";
        private const string PIS_ERROR = "PIS amount doesn't match the expected value. ";
        private const string COFINS_ERROR = "COFINS amount doesn't match the expected value.";
        private const decimal TOLERANCE = 0.01m;
        public int Priority => 2;

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

            var totalBeforeTaxes = request.TUSDAmount + request.TEAmount;
            var expectedPIS = totalBeforeTaxes * (distributorInfo.PISPercentage / 100);
            var expectedCOFINS = totalBeforeTaxes * (distributorInfo.COFINSPercentage / 100);

            if (Math.Abs(request.PISAmount - expectedPIS) > TOLERANCE)
            {
                isValid = false;
                message.Append(PIS_ERROR);
            }

            if (request.COFINSAmount != expectedCOFINS)
            {
                isValid = false;
                message.Append(COFINS_ERROR);
            }

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