/* FirefoxPreferencesParser.java
   Copyright (C) 2011 Red Hat, Inc.

This file is part of IcedTea.

IcedTea 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, version 2.

IcedTea 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.

You should have received a copy of the GNU General Public License along with
IcedTea; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is making a
combined work based on this library. Thus, the terms and conditions of the GNU
General Public License cover the whole combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent modules, and
to copy and distribute the resulting executable under terms of your choice,
provided that you also meet, for each linked independent module, the terms and
conditions of the license of that module. An independent module is a module
which is not derived from or based on this library. If you modify this library,
you may extend this exception to your version of the library, but you are not
obligated to do so. If you do not wish to do so, delete this exception
statement from your version.
*/

package net.sourceforge.jnlp.proxy.browser;

import net.adoptopenjdk.icedteaweb.logging.Logger;
import net.adoptopenjdk.icedteaweb.logging.LoggerFactory;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * <p>
 * A parser for Firefox's preferences file. It can 'parse' Firefox's
 * preferences file and expose the preferences in a simple to use format.
 * </p>
 * Sample usage:
 * <pre><code>
 * FirefoxPreferencesParser p = new FirefoxPreferencesParser(prefsFile);
 * p.parse();
 * Map&lt;String,String&gt; prefs = p.getPreferences();
 * System.out.println("blink allowed: " + prefs.get("browser.blink_allowed"));
 * </code></pre>
 */
public final class FirefoxPreferencesParser implements PreferencesParser {

    private final static Logger LOG = LoggerFactory.getLogger(FirefoxPreferencesParser.class);

    Map<String, String> prefs = null;

    /**
     * Parse the preferences file
     * @throws IOException if an exception occurs while reading the
     * preferences file.
     */
    public void parse() throws IOException {
        /*
         * The Firefox preference file is actually in javascript. It does seem
         * to be nicely formatted, so it should be possible to hack reading it.
         * The correct way of course is to use a javascript library and extract
         * the user_pref object
         */
        prefs = new HashMap<String, String>();

        File prefsFile = FirefoxPreferencesFinder.find();
        BufferedReader reader = new BufferedReader(new FileReader(prefsFile));

        try {
            while (true) {
                String line = reader.readLine();
                // end of stream
                if (line == null) {
                    break;
                }

                line = line.trim();
                if (line.startsWith("user_pref")) {

                    /*
                     * each line is of the form: user_pref("key",value); where value
                     * can be a string in double quotes or an integer or float or
                     * boolean
                     */

                    boolean foundKey = false;
                    boolean foundValue = false;

                    // extract everything inside user_pref( and );
                    String pref = line.substring("user_pref(".length(), line.length() - 2);
                    // key and value are separated by a ,
                    int firstCommaPos = pref.indexOf(',');
                    if (firstCommaPos >= 1) {
                        String key = pref.substring(0, firstCommaPos).trim();
                        if (key.startsWith("\"") && key.endsWith("\"")) {
                            key = key.substring(1, key.length() - 1);
                            if (key.trim().length() > 0) {
                                foundKey = true;
                            }
                        }

                        if (pref.length() > firstCommaPos + 1) {
                            String value = pref.substring(firstCommaPos + 1).trim();
                            if (value.startsWith("\"") && value.endsWith("\"")) {
                                value = value.substring(1, value.length() - 1).trim();
                            }
                            foundValue = true;

                            if (foundKey && foundValue) {
                                //ItwLogger.getLogger().printOutLn("added (\"" + key + "\", \"" + value + "\")");
                                prefs.put(key, value);
                            }
                        }
                    }
                }
            }
        } finally {
            reader.close();
        }
        LOG.info("Read {} entries from Firefox's preferences", prefs.size());
    }

    /**
     * Get the firefox preferences as a map (key,value pair). Note that
     * all values (including integers and booleans) are stored as a string, so
     * conversion to an appropriate type may be required.
     *
     * @return a map containing firefox' preferences
     */
    public Map<String, String> getPreferences() {
        HashMap<String, String> newMap = new HashMap<String, String>();
        newMap.putAll(prefs);
        return newMap;
    }

}
