package geoip

import (
	"log/slog"
	"net"
	"yobbly-gateway-go/internal/logger"

	"github.com/oschwald/geoip2-golang"
)

// GeoIPService предоставляет методы для поиска GeoIP.
type GeoIPService struct {
	reader           *geoip2.Reader
	blockedCountries map[string]struct{}
}

// NewGeoIPService создает новый GeoIPService.
func NewGeoIPService(dbPath string, blockedCountries []string) (*GeoIPService, error) {
	op := "geoip.NewGeoIPService"
	log := logger.NewLoggerWithOp(op)

	reader, err := geoip2.Open(dbPath)
	if err != nil {
		log.Error("failed to open GeoIP database", slog.String("db_path", dbPath), slog.Any("error", err))
		return nil, err
	}

	blockedMap := make(map[string]struct{})
	for _, country := range blockedCountries {
		blockedMap[country] = struct{}{}
	}

	log.Info("GeoIP service initialized", slog.String("db_path", dbPath), slog.Any("blocked_countries", blockedCountries))
	return &GeoIPService{
			reader:           reader,
			blockedCountries: blockedMap,
		},
		nil
}

// IsCountryBlocked проверяет, принадлежит ли данный IP-адрес заблокированной стране.
func (s *GeoIPService) IsCountryBlocked(ipStr string) (bool, string) {
	op := "geoip.IsCountryBlocked"
	log := logger.NewLoggerWithOp(op)

	ip := net.ParseIP(ipStr)
	if ip == nil {
		log.Warn("invalid IP address for GeoIP lookup", slog.String("ip", ipStr))
		return false, ""
	}

	record, err := s.reader.Country(ip)
	if err != nil {
		// Логируем ошибку, но не блокируем, аналогично поведению Python
		log.Error("GeoIP lookup failed", slog.String("ip", ipStr), slog.Any("error", err))
		return false, ""
	}

	countryCode := record.Country.IsoCode
	log.Debug("GeoIP lookup result", slog.String("ip", ipStr), slog.String("country_code", countryCode))

	if _, ok := s.blockedCountries[countryCode]; ok {
		log.Info("access denied for blocked country", slog.String("ip", ipStr), slog.String("country_code", countryCode))
		return true, countryCode
	}

	return false, countryCode
}

// Close закрывает ридер базы данных GeoIP.
func (s *GeoIPService) Close() error {
	op := "geoip.Close"
	log := logger.NewLoggerWithOp(op)

	log.Info("closing GeoIP service")
	return s.reader.Close()
}