/**
 * <p>
 * Copyright © 2009-2010, Bruce-Robert Pocock
 * </p>
 * <p>
 * Based upon public domain sample code provided by Authorize.net
 * </p>
 * <p>
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or (at
 * your option) any later version.
 * </p>
 * <p>
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 * </p>
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 * </p>
 * 
 * @author brpocock
 */



package net.authorize.arb.http;

/*
 * SSL Handshake and Certificate retrieval based on Sun Microsystems
 * InstallCert.java example
 * http://blogs.sun.com/andreas/resource/InstallCert.java
 */

import java.io.*;
import java.net.Socket;
import java.security.KeyStore;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.*;

import org.starhope.appius.game.AppiusClaudiusCaecus;

/**
 * 
 * TODO: The documentation for this type (HttpUtil) is incomplete.
 * (brpocock, Sep 23, 2009)
 * 
 * @author brpocock
 * 
 */
public class HttpUtil {

	/**
	 * 
	 * TODO: The documentation for this type (SavingTrustManager) is
	 * incomplete. (brpocock, Nov 19, 2009)
	 * 
	 */
	private static class SavingTrustManager implements X509TrustManager {
		/**
		 * TODO: document this field
		 * 
		 * chain (SavingTrustManager)
		 */
		X509Certificate [] chain;
		/**
		 * TODO: document this field
		 * 
		 * tm (SavingTrustManager)
		 */
		private final X509TrustManager tm;

		/**
		 * @param tm1 WRITEME
		 */
		SavingTrustManager (final X509TrustManager tm1) {
			tm = tm1;
		}

		/**
		 * This is an overriding method.
		 * 
		 * @see javax.net.ssl.X509TrustManager#checkClientTrusted(java.security.cert.X509Certificate[],
		 *      java.lang.String)
		 */
		public void checkClientTrusted (
				final X509Certificate [] certChain,
				final String authType) throws CertificateException {
			throw new UnsupportedOperationException ();
		}

		/**
		 * This is an overriding method.
		 * 
		 * @see javax.net.ssl.X509TrustManager#checkServerTrusted(java.security.cert.X509Certificate[],
		 *      java.lang.String)
		 */
		public void checkServerTrusted (
				final X509Certificate [] certChain,
				final String authType) throws CertificateException {
			chain = certChain;
			tm.checkServerTrusted (certChain, authType);
		}

		/**
		 * This is an overriding method.
		 * 
		 * @see javax.net.ssl.X509TrustManager#getAcceptedIssuers()
		 */
		public X509Certificate [] getAcceptedIssuers () {
			throw new UnsupportedOperationException ();
		}
	}

	/**
	 * TODO: document this field (brpocock, Sep 23, 2009)
	 * 
	 * CERTIFICATE_FILE (HttpUtil)
	 */
	public final static String CERTIFICATE_FILE = "Authorize.Net.certs";

	/**
	 * TODO: document this field (brpocock, Nov 19, 2009)
	 * 
	 * default_password (HttpUtil)
	 */
	private static final String default_password = "example-passphrase";

	/**
	 * TODO: document this field (brpocock, Sep 23, 2009)
	 * 
	 * HTTP_PORT (HttpUtil)
	 */
	public final static int HTTP_PORT = 80;
	/**
	 * TODO: document this field (brpocock, Sep 23, 2009)
	 * 
	 * HTTPS_PORT (HttpUtil)
	 */
	public final static int HTTPS_PORT = 443;

	/**
	 * TODO: document this field (brpocock, Nov 19, 2009)
	 * 
	 * hostProperty (HttpUtil)
	 */
	private String hostProperty = null;
	/**
	 * TODO: document this field (brpocock, Nov 19, 2009)
	 * 
	 * is_secure (HttpUtil)
	 */
	private boolean is_secure = false;
	/**
	 * TODO: document this field (brpocock, Nov 19, 2009)
	 * 
	 * keys (HttpUtil)
	 */
	private KeyStore keys = null;

	/**
	 * TODO: document this field (brpocock, Nov 19, 2009)
	 * 
	 * pathProperty (HttpUtil)
	 */
	private String pathProperty = null;

	/**
	 * @param url WRITEME
	 */
	public HttpUtil (final java.net.URL url) {
		hostProperty = url.getHost ();
		pathProperty = url.getPath ();
		final String protocol = url.getProtocol ();
		if (protocol.equals ("https")) {
			is_secure = true;
		}
	}

	/**
	 * TODO: document this method (brpocock, Sep 23, 2009)
	 * 
	 */
	public void cleanup () {
		final File file = new File (HttpUtil.CERTIFICATE_FILE);
		if (file.exists ()) {
			// System.out.println("Cleaning up certificates");
			final boolean deleted = file.delete ();
			if (!deleted) {
				// FIXME
			}
		}
	}

	/**
	 * TODO: document this method (brpocock, Nov 19, 2009)
	 * 
	 * @param socket WRITEME
	 * @param path WRITEME
	 * @param post_data WRITEME
	 * @return WRITEME
	 * @throws IOException WRITEME
	 */
	private String doSocketTransfer (final Socket socket,
			final String path, final String post_data)
	throws IOException {
		String line;
		final StringBuffer sb = new StringBuffer ();
		String method = "GET";
		if (post_data != null) {
			method = "POST";
		}
		final BufferedWriter out = new BufferedWriter (
				new OutputStreamWriter (socket.getOutputStream ()));
		final BufferedReader in = new BufferedReader (
				new InputStreamReader (socket.getInputStream ()));
		out.write (method + " " + path + " HTTP/1.0\n");
		if (post_data != null) {
			out.write ("Content-Length: "
					+ Integer.toString (post_data.length ()) + "\n");
			out.write ("Content-Type: text/xml; charset=\"utf-8\"\n");
		}
		out.write ("\n");
		if (post_data != null) {
			out.write (post_data);
		}
		out.flush ();

		while ( (line = in.readLine ()) != null) {
			sb.append (line + "\r\n");
		}
		out.close ();
		in.close ();
		socket.close ();
		return sb.toString ();
	}

	/**
	 * TODO: document this method (brpocock, Nov 19, 2009)
	 * 
	 * @param thatHost WRITEME
	 * @param path WRITEME
	 * @param post_data WRITEME
	 * @return WRITEME
	 */
	private String GetHttpSocket (final String thatHost,
			final String path, final String post_data) {
		Socket socket = null;
		try {
			socket = new Socket (thatHost, HttpUtil.HTTP_PORT);
			socket.setSoTimeout (10000);
			try {
				return doSocketTransfer (socket, path, post_data);
			} catch (final Exception e) {
				System.out.println ();
				AppiusClaudiusCaecus.reportBug (e);
			}
		} catch (final Exception e) {
			System.out.println ("Error: " + e);
		} finally {
			try {
				if (null != socket) {
					socket.close ();
				}
			} catch (final IOException e) {
				AppiusClaudiusCaecus.reportBug (e);
			}
		}
		return null;
	}

	/**
	 * 
	 * TODO: document this method (brpocock, Oct 13, 2009)
	 * 
	 * @param certificate_password WRITEME
	 * @return WRITEME
	 */
	private KeyStore getKeyStore (final char [] certificate_password) {
		if (keys != null)
			return keys;
		InputStream in = null;
		try {
			final File file = new File (HttpUtil.CERTIFICATE_FILE);
			final KeyStore ks = KeyStore.getInstance (KeyStore
					.getDefaultType ());
			if (file.exists () == false)
				// System.out.println("Null keystore");
				return null;
			in = new FileInputStream (file);
			ks.load (in, certificate_password);
			in.close ();
			keys = ks;
		} catch (final Exception e) {
			System.out.println (e);
		} finally {
			if (null != in) {
				try {
					in.close ();
				} catch (final IOException e) {
					AppiusClaudiusCaecus.reportBug (e);
				}
			}
		}
		return keys;
	}

	/**
	 * 
	 * TODO: document this method (brpocock, Oct 13, 2009)
	 * 
	 * @param thatHost WRITEME
	 * @param path WRITEME
	 * @param post_data WRITEME
	 * @return WRITEME
	 */
	private String GetSecureHttpSocket (final String thatHost,
			final String path, final String post_data) {
		return this.GetSecureHttpSocket (HttpUtil.default_password,
				thatHost, path, post_data);
	}

	/**
	 * TODO: document this method (brpocock, Nov 19, 2009)
	 * 
	 * @param password WRITEME
	 * @param host WRITEME
	 * @param path WRITEME
	 * @param post_data WRITEME
	 * @return WRITEME
	 */
	private String GetSecureHttpSocket (final String password,
			final String host, final String path, final String post_data) {
		// Get a Socket factory
		try {

			if (this.initializeKeyStore (password, host) == false)
				return null;
			final SSLContext context = SSLContext.getInstance ("TLS");
			final TrustManagerFactory tmf = TrustManagerFactory
			.getInstance (TrustManagerFactory
					.getDefaultAlgorithm ());
			tmf.init (getKeyStore (password.toCharArray ()));
			final X509TrustManager defaultTrustManager = (X509TrustManager) tmf
			.getTrustManagers () [0];
			final SavingTrustManager tm = new SavingTrustManager (
					defaultTrustManager);
			context.init (null, new TrustManager [] { tm }, null);
			final SSLSocketFactory factory = context
			.getSocketFactory ();
			final SSLSocket socket = (SSLSocket) factory.createSocket (
					host, HttpUtil.HTTPS_PORT);
			socket.setSoTimeout (10000);

			try {
				// System.out.println("Starting SSL handshake...");
				socket.startHandshake ();

				return doSocketTransfer (socket, path, post_data);
			} catch (final SSLException e) {
				System.out.println ();
				e.printStackTrace (System.out);
			}
		} catch (final Exception e) {
			System.out.println ("Error: " + e);
		}
		return null;
	}

	/**
	 * TODO: document this method (brpocock, Sep 23, 2009)
	 * 
	 * @return WRITEME
	 */
	public String getUrl () {
		if (is_secure)
			return this.GetSecureHttpSocket (hostProperty,
					pathProperty, null);
		return GetHttpSocket (hostProperty, pathProperty, null);
	}

	/**
	 * TODO: document this method (brpocock, Sep 23, 2009)
	 * 
	 * @param theHost WRITEME
	 * @return WRITEME
	 */
	public boolean initializeKeyStore (final String theHost) {
		return this.initializeKeyStore (HttpUtil.default_password,
				theHost);
	}

	/**
	 * TODO: document this method (brpocock, Sep 23, 2009)
	 * 
	 * @param password WRITEME
	 * @param host WRITEME
	 * @return WRITEME
	 */
	public boolean initializeKeyStore (final String password,
			final String host) {
		OutputStream out = null;
		try {
			final char [] certificate_password = password
			.toCharArray ();

			KeyStore ks = getKeyStore (certificate_password);
			if (ks != null)
				/*
				 * System.out.println("Loading KeyStore " + file +
				 * "..."); InputStream in = new FileInputStream(file);
				 * 
				 * ks.load(in, certificate_password); in.close();
				 */
				// System.out.println("Keystore exists.");
				return true;

			ks = KeyStore.getInstance (KeyStore.getDefaultType ());

			// Initialize the empty keystore
			//
			ks.load (null, certificate_password);

			final SSLContext context = SSLContext.getInstance ("TLS");
			final TrustManagerFactory tmf = TrustManagerFactory
			.getInstance (TrustManagerFactory
					.getDefaultAlgorithm ());
			tmf.init (ks);
			final X509TrustManager defaultTrustManager = (X509TrustManager) tmf
			.getTrustManagers () [0];
			final SavingTrustManager tm = new SavingTrustManager (
					defaultTrustManager);
			context.init (null, new TrustManager [] { tm }, null);
			final SSLSocketFactory factory = context
			.getSocketFactory ();
			// System.out.println("Opening connection to " + host + ":"
			// + HTTPS_PORT + "...");
			final SSLSocket socket = (SSLSocket) factory.createSocket (
					host, HttpUtil.HTTPS_PORT);

			socket.setSoTimeout (10000);
			try {
				// System.out.println("Starting SSL handshake...");
				socket.startHandshake ();
				socket.close ();
				System.out.println ();
				// System.out.println("No errors, certificate is already trusted");
			} catch (final SSLException e) {
				// System.out.println();
				// e.printStackTrace(System.out);
			}

			final X509Certificate [] chain = tm.chain;
			if (chain == null || chain.length == 0) {
				System.out
				.println ("Could not obtain server certificate chain");
				return false;
			}

			// System.out.println("Cert Chain: " + chain.length);

			for (int i = 0; i < chain.length; i++ ) {
				final X509Certificate cert = chain [i];
				final String alias = host + "-" + (i + 1);
				ks.setCertificateEntry (alias, cert);
			}

			out = new FileOutputStream (HttpUtil.CERTIFICATE_FILE);
			ks.store (out, certificate_password);
			out.close ();

			return true;

		} catch (final Exception e) {
			System.out.println (e);
		} finally {
			if (null != out) {
				try {
					out.close ();
				} catch (final IOException e) {
					// Default catch action, report bug (brpocock, Oct
					// 13, 2009)
					AppiusClaudiusCaecus.reportBug (e);
				}
			}
		}
		return false;
	}

	/**
	 * TODO: document this method (brpocock, Sep 23, 2009)
	 * 
	 * @param data WRITEME
	 * @return WRITEME
	 */
	public String postUrl (final String data) {
		if (is_secure)
			return this.GetSecureHttpSocket (hostProperty,
					pathProperty, data);
		return GetHttpSocket (hostProperty, pathProperty, data);
	}
}