/*

 * Copyright (c) 2012, 2018, Oracle and/or its affiliates. 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.  Oracle designates this

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

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.jfr.internal.jfc;

import java.io.CharArrayReader;

import java.io.CharArrayWriter;

import java.io.IOException;

import java.io.Reader;

import java.text.ParseException;

import jdk.internal.org.xml.sax.InputSource;

import jdk.internal.org.xml.sax.SAXException;

import jdk.internal.util.xml.SAXParser;

import jdk.internal.util.xml.impl.SAXParserImpl;

import jdk.jfr.Configuration;

import jdk.jfr.internal.PrivateAccess;

/**

 * Parses a JDK Flight Recorder Configuration file (.jfc)

 */

final class JFCParser {

    static final String FILE_EXTENSION = ".jfc";

    private static final int MAXIMUM_FILE_SIZE = 1024 * 1024;

    public static Configuration createConfiguration(String name, Reader reader) throws IOException, ParseException {

        return createConfiguration(name, readContent(reader));

    }

    public static Configuration createConfiguration(String name, String content) throws IOException, ParseException {

        try {

            JFCParserHandler ch = new JFCParserHandler();

            parseXML(content, ch);

            return PrivateAccess.getInstance().newConfiguration(name, ch.label, ch.description, ch.provider, ch.settings, content);

        } catch (IllegalArgumentException iae) {

            throw new ParseException(iae.getMessage(), -1);

        } catch (SAXException e) {

            ParseException pe =  new ParseException("Error reading JFC file. " + e.getMessage(), -1);

            pe.initCause(e);

            throw pe;

        }

    }

    private static void parseXML(String content, JFCParserHandler ch) throws SAXException, IOException {

        CharArrayReader r = new CharArrayReader(content.toCharArray());

        SAXParser parser = new SAXParserImpl();

        parser.parse(new InputSource(r), ch);

    }

    private static String readContent(Reader r) throws IOException {

        CharArrayWriter writer = new CharArrayWriter(1024);

        int count = 0;

        int ch;

        while ((ch = r.read()) != -1) {

            writer.write(ch);

            count++;

            if (count >= MAXIMUM_FILE_SIZE) {

                throw new IOException("Presets with more than " + MAXIMUM_FILE_SIZE + " characters can't be read.");

            }

        }

        return new String(writer.toCharArray());

    }

}