package org.parabot.environment.api.utils;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import org.parabot.core.io.ProgressListener;
import org.parabot.core.io.SizeInputStream;

/**
 * 
 * A WebUtil class fetches data from an URL
 * 
 * @author Everel
 * 
 */
public class WebUtil {
	private static String agent = "Mozilla/5.0 (Wind0ws NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.112 Safari/535.1";

	/**
	 * Agent to set at a URL connection
	 * 
	 * @param userAgent
	 */
	public static void setUserAgent(final String userAgent) {
		agent = userAgent;
	}

	/**
	 * Gets useragent
	 * 
	 * @return useragent
	 */
	public static String getUserAgent() {
		return agent;
	}

	/**
	 * Fetches content of a page
	 * 
	 * @param location
	 * @return contents of page
	 * @throws MalformedURLException
	 */
	public static String getContents(final String location)
			throws MalformedURLException {
		return getContents(new URL(location));
	}

	/**
	 * Get contents from URL
	 * 
	 * @param url
	 * @return page contents
	 */
	public static String getContents(final URL url) {
		return getContents(getConnection(url));
	}

	/**
	 * Gets contents from URLConnection
	 * 
	 * @param urlConnection
	 * @return page contents
	 */
	public static String getContents(URLConnection urlConnection) {
		try {
			final BufferedReader in = getReader(urlConnection);
			final StringBuilder builder = new StringBuilder();
			String line;
			while ((line = in.readLine()) != null) {
				builder.append(line);
			}
			in.close();
			return builder.toString();
		} catch (Throwable t) {
			t.printStackTrace();
		}
		return null;
	}

	/**
	 * Gets buffered reader from string url
	 * 
	 * @param url
	 * @return bufferedreader
	 */
	public static BufferedReader getReader(final String url) {
		try {
			return getReader(new URL(url));
		} catch (MalformedURLException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * Gets BufferedReader from URL
	 * 
	 * @param url
	 * @return BufferedReader from URL
	 */
	public static BufferedReader getReader(final URL url) {
		return getReader(getConnection(url));
	}

	public static BufferedReader getReader(final URLConnection urlConnection) {
		try {
			return new BufferedReader(new InputStreamReader(
					urlConnection.getInputStream()));
		} catch (Throwable t) {
			t.printStackTrace();
		}
		return null;
	}

	/**
	 * Gets inputstream from url
	 * 
	 * @param url
	 * @return inputstream from url
	 */
	public static InputStream getInputStream(final URL url) {
		final URLConnection con = getConnection(url);
		try {
			return con.getInputStream();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * Opens a connection
	 * 
	 * @param url
	 * @return URLConnection to URL
	 */
	public static URLConnection getConnection(final URL url) {
		try {
			final URLConnection con = url.openConnection();
			con.setRequestProperty("User-Agent", agent);
			return con;
		} catch (Throwable t) {
			t.printStackTrace();
		}
		return null;
	}

	/**
	 * Downloads a file on the internet
	 * @param url
	 * @param destination
	 * @param listener
	 */
	public static void downloadFile(final URL url, final File destination,
			final ProgressListener listener) {
		try {
			final URLConnection connection = getConnection(url);
			int size = connection.getContentLength();
			SizeInputStream sizeInputStream = new SizeInputStream(
					connection.getInputStream(), size, listener);
			BufferedInputStream in = new BufferedInputStream(sizeInputStream);
			FileOutputStream fileOut = new FileOutputStream(destination);
			try {
				byte data[] = new byte[1024];
				int count;
				while ((count = in.read(data, 0, 1024)) != -1) {
					fileOut.write(data, 0, count);
				}
			} finally {
				if (in != null)
					in.close();
				if (fileOut != null)
					fileOut.close();
			}
		} catch (Throwable t) {
			t.printStackTrace();
		}
	}

}