package com.paymentlink.config;

import com.paymentlink.exception.RegionBlockedException;
import com.paymentlink.model.dto.CountryInfo;
import com.paymentlink.service.GeoIpService;
import com.paymentlink.service.RegionService;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;

@Component
public class LocalizationInterceptor implements HandlerInterceptor {

    private static final Logger logger = LoggerFactory.getLogger(LocalizationInterceptor.class);

    private final GeoIpService geoIpService;
    private final RegionService regionService;

    @Value("${region.blocking.enabled:true}")
    private boolean regionBlockingEnabled;

    public LocalizationInterceptor(GeoIpService geoIpService, RegionService regionService) {
        this.geoIpService = geoIpService;
        this.regionService = regionService;
    }

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
        // Check if client already has region preference (from cookie or header)
        String clientRegion = request.getHeader("X-User-Region");
        
        CountryInfo countryInfo;
        
        if (clientRegion != null && !clientRegion.isEmpty()) {
            // Client already selected a region, use that instead of GeoIP
            logger.debug("Using client-selected region: {}", clientRegion);
            countryInfo = regionService.getRegion(clientRegion) != null 
                ? buildCountryInfoFromRegion(regionService.getRegion(clientRegion))
                : geoIpService.getCountryFromRequest(request);
        } else {
            // Only do GeoIP lookup if no region preference exists
            // This typically happens once on first visit
            countryInfo = geoIpService.getCountryFromRequest(request);
            logger.debug("GeoIP lookup performed for first-time visitor from IP");
        }

        // Set country info in request attributes for controllers to use
        request.setAttribute("countryCode", countryInfo.getCountryCode());
        request.setAttribute("countryName", countryInfo.getCountryName());
        request.setAttribute("languageCode", countryInfo.getLanguageCode());
        request.setAttribute("currencyCode", countryInfo.getCurrencyCode());

        logger.debug("Request from country: {} ({}), language: {}, currency: {}",
                countryInfo.getCountryName(),
                countryInfo.getCountryCode(),
                countryInfo.getLanguageCode(),
                countryInfo.getCurrencyCode());

        // Check if region blocking is enabled
        if (regionBlockingEnabled) {
            // Check if country is enabled
            if (countryInfo.getEnabled() == null || !countryInfo.getEnabled()) {
                boolean isEnabled = regionService.isCountryEnabled(countryInfo.getCountryCode());
                if (!isEnabled) {
                    logger.warn("Blocked request from disabled region: {} ({})",
                            countryInfo.getCountryName(),
                            countryInfo.getCountryCode());
                    throw new RegionBlockedException(countryInfo.getCountryCode(), countryInfo.getCountryName());
                }
            }
        }

        return true;
    }
    
    private CountryInfo buildCountryInfoFromRegion(com.paymentlink.model.entity.Region region) {
        return CountryInfo.builder()
                .countryCode(region.getCountryCode())
                .countryName(region.getCountryName())
                .languageCode(region.getLanguageCode())
                .currencyCode(region.getCurrencyCode())
                .enabled(region.getEnabled())
                .build();
    }
}