/*

 * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.net.www.http;

import java.io.*;

import java.util.ArrayList;

import java.util.logging.Level;

import java.util.logging.Logger;

import sun.net.NetProperties;

import java.util.regex.*;

/**

 * Main class of the HTTP traffic capture tool.

 * Captures are triggered by the sun.net.http.captureRules system property.

 * If set, it should point to a file containing the capture rules.

 * Format for the file is simple:

 * - 1 rule per line

 * - Lines starting with a # are considered comments and ignored

 * - a rule is a pair of a regular expression and file pattern, separated by a comma

 * - The regular expression is applied to URLs, if it matches, the traffic for

 *   that URL will be captured in the associated file.

 * - if the file name contains a '%d', then that sequence will be replaced by a

 *   unique random number for each URL. This allow for multi-threaded captures

 *   of URLs matching the same pattern.

 * - Rules are checked in sequence, in the same order as in the file, until a

 *   match is found or the end of the list is reached.

 *

 * Examples of rules:

 * www\.sun\.com , sun%d.log

 * yahoo\.com\/.*asf , yahoo.log

 *

 * @author jccollet

 */

public class HttpCapture {

    private File file = null;

    private boolean incoming = true;

    private BufferedWriter out = null;

    private static boolean initialized = false;

    private static volatile ArrayList<Pattern> patterns = null;

    private static volatile ArrayList<String> capFiles = null;

    private static synchronized void init() {

        initialized = true;

        String rulesFile = java.security.AccessController.doPrivileged(

            new java.security.PrivilegedAction<String>() {

                public String run() {

                    return NetProperties.get("sun.net.http.captureRules");

                }

            });

        if (rulesFile != null && !rulesFile.isEmpty()) {

            BufferedReader in;

            try {

                in = new BufferedReader(new FileReader(rulesFile));

            } catch (FileNotFoundException ex) {

                return;

            }

            try {

                String line = in.readLine();

                while (line != null) {

                    line = line.trim();

                    if (!line.startsWith("#")) {

                        // skip line if it's a comment

                        String[] s = line.split(",");

                        if (s.length == 2) {

                            if (patterns == null) {

                                patterns = new ArrayList<Pattern>();

                                capFiles = new ArrayList<String>();

                            }

                            patterns.add(Pattern.compile(s[0].trim()));

                            capFiles.add(s[1].trim());

                        }

                    }

                    line = in.readLine();

                }

            } catch (IOException ioe) {

            } finally {

                try {

                    in.close();

                } catch (IOException ex) {

                }

            }

        }

    }

    private static synchronized boolean isInitialized() {

        return initialized;

    }

    private HttpCapture(File f, java.net.URL url) {

        file = f;

        try {

            out = new BufferedWriter(new FileWriter(file, true));

            out.write("URL: " + url + "\n");

        } catch (IOException ex) {

            Logger.getLogger(HttpCapture.class.getName()).log(Level.SEVERE, null, ex);

        }

    }

    public synchronized void sent(int c) throws IOException {

        if (incoming) {

            out.write("\n------>\n");

            incoming = false;

            out.flush();

        }

        out.write(c);

    }

    public synchronized void received(int c) throws IOException {

        if (!incoming) {

            out.write("\n<------\n");

            incoming = true;

            out.flush();

        }

        out.write(c);

    }

    public synchronized void flush() throws IOException {

        out.flush();

    }

    public static HttpCapture getCapture(java.net.URL url) {

        if (!isInitialized()) {

            init();

        }

        if (patterns == null || patterns.isEmpty()) {

            return null;

        }

        String s = url.toString();

        for (int i = 0; i < patterns.size(); i++) {

            Pattern p = patterns.get(i);

            if (p.matcher(s).find()) {

                String f = capFiles.get(i);

                File fi;

                if (f.indexOf("%d") >= 0) {

                    java.util.Random rand = new java.util.Random();

                    do {

                        String f2 = f.replace("%d", Integer.toString(rand.nextInt()));

                        fi = new File(f2);

                    } while (fi.exists());

                } else {

                    fi = new File(f);

                }

                return new HttpCapture(fi, url);

            }

        }

        return null;

    }

}