package network;

import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import network.exceptions.*;

//Ref: https://stackoverflow.com/questions/2793150/how-to-use-java-net-urlconnection-to-fire-and-handle-http-requests
public class Net {
    public static String urlStringBuilder(String url, String... paras) throws ParaMismatchException {
        String urlString = url;
        String charset = "UTF-8";
        if ((paras.length % 2) != 0) {
            throw new ParaMismatchException("Except even paras, but have " + paras.length);
        }
        if (paras.length != 0) {
            urlString += "?";
            try {
                for (int i = 0; i < paras.length - 3; i = i + 2) {
                    urlString += paras[i] + "=" + URLEncoder.encode(paras[i + 1], charset) + "&";
                }
                urlString += paras[paras.length - 2] + "=" + URLEncoder.encode(paras[paras.length - 1], charset);
            } catch (UnsupportedEncodingException e) {
                System.out.println("Error during encoding url: Unsupported encoding");
                e.printStackTrace();
            }
        }
        return urlString;
    }

    public static InputStream urlToInputStream(String url) throws IOException {
        try {
            return (new URL(url).openStream());
        } catch (IOException e) {
            throw e;
        }
    }
}