package eu.openaire.urls_controller.util;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.env.Environment;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.URL;

public class UriBuilder {

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

    public static String baseUrl = null;

    public UriBuilder(Environment environment)
    {
        baseUrl = "http";
        String sslEnabled = environment.getProperty("server.ssl.enabled");
        if (sslEnabled == null) { // It's expected to not exist if there is no SSL-configuration.
            logger.warn("No property \"server.ssl.enabled\" was found in \"application.properties\". Continuing with plain HTTP..");
            sslEnabled = "false";
        }
        baseUrl += sslEnabled.equals("true") ? "s" : "";
        baseUrl += "://";

        String hostName = getPublicIP();
        if ( hostName == null )
            hostName = InetAddress.getLoopbackAddress().getHostName();   // Non-null.

        baseUrl += hostName;
        String serverPort = environment.getProperty("server.port");
        if (serverPort == null) { // This is unacceptable!
            logger.error("No property \"server.port\" was found in \"application.properties\"!");
            System.exit(-1);    // Well, I guess the Spring Boot would not start in this case anyway.
        }
        baseUrl += ":" + serverPort;

        String baseInternalPath = environment.getProperty("server.servlet.context-path");
        if ( baseInternalPath != null ) {
            if ( !baseInternalPath.startsWith("/") )
                baseUrl += "/";
            baseUrl += baseInternalPath;
            if ( !baseInternalPath.endsWith("/") )
                baseUrl += "/";
        } else {
            logger.warn("No property \"server.servlet.context-path\" was found in \"application.properties\"!");    // Yes it's expected.
            baseUrl += "/";
        }

        logger.debug("ServerBaseURL: " + baseUrl);
    }

    private static String getPublicIP()
    {
        String publicIpAddress = "";
        URL url_name;
        try {
            url_name = new URL("https://api.ipify.org/");
        } catch (MalformedURLException mue) {
            logger.warn(mue.getMessage());
            return null;
        }
        try (BufferedReader bf = new BufferedReader(new InputStreamReader(url_name.openStream()))) {
            publicIpAddress = bf.readLine().trim();
        } catch (Exception e) {
            logger.warn("Cannot get the publicIP address for this machine!", e);
            return null;
        }
        return publicIpAddress;
    }

    public static String getBaseUrl() {
        return baseUrl;
    }

    public static void setBaseUrl(String baseUrl) {
        UriBuilder.baseUrl = baseUrl;
    }

}