/*

 * Copyright (c) 2016, 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;

import java.io.IOException;

import java.io.Reader;

import java.nio.file.Files;

import java.nio.file.Path;

import java.text.ParseException;

import java.util.ArrayList;

import java.util.Collections;

import java.util.LinkedHashMap;

import java.util.List;

import java.util.Map;

import java.util.Objects;

import jdk.jfr.internal.JVMSupport;

import jdk.jfr.internal.jfc.JFC;

/**

 * A collection of settings and metadata describing the configuration.

 *

 * @since 9

 */

public final class Configuration {

    private final Map<String, String> settings;

    private final String label;

    private final String description;

    private final String provider;

    private final String contents;

    private final String name;

    // package private

    Configuration(String name, String label, String description, String provider, Map<String, String> settings, String contents) {

        this.name = name;

        this.label = label;

        this.description = description;

        this.provider = provider;

        this.settings = settings;

        this.contents = contents;

    }

    /**

     * Returns the settings that specifies how a recording is configured.

     * <p>

     * Modifying the returned {@code Map} object doesn't change the

     * configuration.

     *

     * @return settings, not {@code null}

     */

    public Map<String, String> getSettings() {

        return new LinkedHashMap<String, String>(settings);

    }

    /**

     * Returns an identifying name (for example, {@code "default" or "profile")}.

     *

     * @return the name, or {@code null} if it doesn't exist

     */

    public String getName() {

        return this.name;

    }

    /**

     * Returns a human-readable name (for example, {@code "Continuous" or "Profiling"}}.

     *

     * @return the label, or {@code null} if it doesn't exist

     */

    public String getLabel() {

        return this.label;

    }

    /**

     * Returns a short sentence that describes the configuration (for example

     * {@code "Low

     * overhead configuration safe for continuous use in production

     * environments"})

     *

     * @return the description, or {@code null} if it doesn't exist

     */

    public String getDescription() {

        return description;

    }

    /**

     * Returns who created the configuration (for example {@code "OpenJDK"}).

     *

     * @return the provider, or {@code null} if it doesn't exist

     */

    public String getProvider() {

        return provider;

    }

    /**

     * Returns a textual representation of the configuration (for example, the

     * contents of a JFC file).

     *

     * @return contents, or {@code null} if it doesn't exist

     *

     * @see Configuration#getContents()

     */

    public String getContents() {

        return contents;

    }

    /**

     * Reads a configuration from a file.

     *

     * @param path the file that contains the configuration, not {@code null}

     * @return the read {@link Configuration}, not {@code null}

     * @throws ParseException if the file can't be parsed

     * @throws IOException if the file can't be read

     * @throws SecurityException if a security manager exists and its

     *         {@code checkRead} method denies read access to the file.

     *

     * @see java.io.File#getPath()

     * @see java.lang.SecurityManager#checkRead(java.lang.String)

     */

    public static Configuration create(Path path) throws IOException, ParseException {

        Objects.requireNonNull(path);

        JVMSupport.ensureWithIOException();

        try (Reader reader = Files.newBufferedReader(path)) {

            return JFC.create(JFC.nameFromPath(path), reader);

        }

    }

    /**

     * Reads a configuration from a character stream.

     *

     * @param reader a {@code Reader} that provides the configuration contents, not

     *        {@code null}

     * @return a configuration, not {@code null}

     * @throws IOException if an I/O error occurs while trying to read contents

     *         from the {@code Reader}

     * @throws ParseException if the file can't be parsed

     */

    public static Configuration create(Reader reader) throws IOException, ParseException {

        Objects.requireNonNull(reader);

        JVMSupport.ensureWithIOException();

        return JFC.create(null, reader);

    }

    /**

     * Returns a predefined configuration.

     * <p>

     * See {@link Configuration#getConfigurations()} for available configuration

     * names.

     *

     * @param name the name of the configuration (for example, {@code "default"} or

     *        {@code "profile"})

     * @return a configuration, not {@code null}

     *

     * @throws IOException if a configuration with the given name does not

     *         exist, or if an I/O error occurs while reading the

     *         configuration file

     * @throws ParseException if the configuration file can't be parsed

     */

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

        JVMSupport.ensureWithIOException();

        return JFC.getPredefined(name);

    }

    /**

     * Returns an immutable list of predefined configurations for this Java Virtual Machine (JVM).

     *

     * @return the list of predefined configurations, not {@code null}

     */

    public static List<Configuration> getConfigurations() {

        if (JVMSupport.isNotAvailable()) {

            return new ArrayList<>();

        }

        return Collections.unmodifiableList(JFC.getConfigurations());

    }

}