PrismLauncher/libraries/launcher/org/prismlauncher/utils/logging/Log.java

// SPDX-License-Identifier: GPL-3.0-only
/*
 *  PolyMC - Minecraft Launcher
 *  Copyright (C) 2022 TheKodeToad <TheKodeToad@proton.me>
 *
 *  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, version 3.
 *
 *  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.
 *
 *  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 obliged to do so. If you do not wish to do
 *  so, delete this exception statement from your version.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package org.prismlauncher.utils.logging;

import java.io.PrintStream;

/**
 * Used to print messages with different levels used to colourise the output.
 * Used instead of a logging framework, as the launcher knows how to parse these
 * messages.
 */
public final class Log {

    private static final PrintStream ERROR_PREFIX = new PrintStream(System.err) {
        @Override
        public void println(String x) {
            error(x);
        }

        @Override
        public void println(Object x) {
            error(String.valueOf(x));
        }
    }, FATAL_PREFIX = new PrintStream(System.err) {
        @Override
        public void println(String x) {
            fatal(x);
        }

        @Override
        public void println(Object x) {
            fatal(String.valueOf(x));
        }
    };

    private static final boolean DEBUG = Boolean.getBoolean("org.prismlauncher.debug");

    private Log() {
    }

    public static void blankLine() {
        System.out.println();
    }

    public static void launcher(String message) {
        log(message, Level.LAUNCHER);
    }

    public static void error(String message) {
        log(message, Level.ERROR);
    }

    public static void debug(String message) {
        if (!DEBUG)
            return;

        log(message, Level.DEBUG);
    }

    public static void info(String message) {
        log(message, Level.INFO);
    }

    public static void warning(String message) {
        log(message, Level.WARNING);
    }

    public static void error(String message, Throwable e) {
        error(message);
        e.printStackTrace(ERROR_PREFIX);
    }

    public static void fatal(String message) {
        log(message, Level.FATAL);
    }

    public static void fatal(String message, Throwable e) {
        fatal(message);
        e.printStackTrace(FATAL_PREFIX);
    }

    /**
     * Logs a message with the prefix !![LEVEL]!.
     *
     * @param message The message
     * @param level   The level
     */
    public static void log(String message, Level level) {
        String prefix = "!![" + level.name + "]!";
        // prefix first line
        message = prefix + message;
        // prefix subsequent lines
        message = message.replace("\n", "\n" + prefix);

        if (level.stderr)
            System.err.println(message);
        else
            System.out.println(message);
    }

}