package net.hellmann.platform.authproxy.proxy.filter;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static net.hellmann.platform.authproxy.proxy.header.Header.*;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;

;

@Component
public class RemoveDangerousHeader extends ZuulFilter {

    private static final Logger LOGGER = LoggerFactory.getLogger(RemoveDangerousHeader.class);


    private final static List<String> IGNORED_HEADER = Arrays.asList("x-auth-secret", "x-auth-cn",
            HELLMANN_USER, HELLMANN_REQUEST_ID, SERVICE_TO_SERVICE,
            HELLMANN_USER_HEADER, HELLMANN_USER_HEADER_SIG,
            PERMISSIONS_FOR_USER, PERMISSIONS_FOR_USER_SIG, SECRET_KEY);

    @Override
    public String filterType() {
        return PRE_TYPE;
    }

    @Override
    public int filterOrder() {
        // RUN EARLY BEFORE ROUTE FILTER ADD ALL SECURITY HEADER
        return 1000;
    }


    @Override
    public boolean shouldFilter() {
        RequestContext context = RequestContext.getCurrentContext();
        return context.getThrowable() == null
                && (context.getZuulRequestHeaders() != null && !context.getZuulRequestHeaders().isEmpty());
    }

    @Override
    public Object run() {
        RequestContext context = RequestContext.getCurrentContext();

        HttpServletRequest request = context.getRequest();



        Map<String, String> filteredResponseHeaders = new HashMap<>();
        Map<String, String> zuulRequestHeaders = context.getZuulRequestHeaders();
        if (zuulRequestHeaders != null) {
            for (String headerKey : zuulRequestHeaders.keySet()) {
                if (!IGNORED_HEADER.contains(headerKey)) {
                    filteredResponseHeaders.put(headerKey, zuulRequestHeaders.get(headerKey));
                } else {
                    LOGGER.info("Remove outside header " + headerKey + " value : " + zuulRequestHeaders.get(headerKey));
                }
            }
        }
        context.remove("zuulRequestHeaders");
        context.put("zuulRequestHeaders", filteredResponseHeaders);
        return null;
    }


}