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/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core;

import java.io.OutputStream;
import java.util.Arrays;

import ch.qos.logback.core.joran.spi.ConsoleTarget;
import ch.qos.logback.core.status.Status;
import ch.qos.logback.core.status.WarnStatus;
import ch.qos.logback.core.util.EnvUtil;
import ch.qos.logback.core.util.OptionHelper;

/**
 * ConsoleAppender appends log events to System.out or
 * System.err using a layout specified by the user. The default
 * target is System.out.
 * 
 * For more information about this appender, please refer to the online manual
 * at http://logback.qos.ch/manual/appenders.html#ConsoleAppender
 *
 * @author Ceki Gülcü
 * @author Tom SH Liu
 * @author Ruediger Dohna
 */

public class ConsoleAppender extends OutputStreamAppender {

    protected ConsoleTarget target = ConsoleTarget.SystemOut;
    protected boolean withJansi = false;

    private final static String WindowsAnsiOutputStream_CLASS_NAME = "org.fusesource.jansi.WindowsAnsiOutputStream";

    /**
     * Sets the value of the Target option. Recognized values are
     * "System.out" and "System.err". Any other value will be ignored.
     */
    public void setTarget(String value) {
        ConsoleTarget t = ConsoleTarget.findByName(value.trim());
        if (t == null) {
            targetWarn(value);
        } else {
            target = t;
        }
    }

    /**
     * Returns the current value of the target property. The default value
     * of the option is "System.out".
     * 
     * See also {@link #setTarget}.
     */
    public String getTarget() {
        return target.getName();
    }

    private void targetWarn(String val) {
        Status status = new WarnStatus("[" + val + "] should be one of " + Arrays.toString(ConsoleTarget.values()), this);
        status.add(new WarnStatus("Using previously set target, System.out by default.", this));
        addStatus(status);
    }

    @Override
    public void start() {
        OutputStream targetStream = target.getStream();
        // enable jansi only on Windows and only if withJansi set to true
        if (EnvUtil.isWindows() && withJansi) {
            targetStream = getTargetStreamForWindows(targetStream);
        }
        setOutputStream(targetStream);
        super.start();
    }

    private OutputStream getTargetStreamForWindows(OutputStream targetStream) {
        try {
            addInfo("Enabling JANSI WindowsAnsiOutputStream for the console.");
            Object windowsAnsiOutputStream = OptionHelper.instantiateByClassNameAndParameter(WindowsAnsiOutputStream_CLASS_NAME, Object.class, context,
                            OutputStream.class, targetStream);
            return (OutputStream) windowsAnsiOutputStream;
        } catch (Exception e) {
            addWarn("Failed to create WindowsAnsiOutputStream. Falling back on the default stream.", e);
        }
        return targetStream;
    }

    /**
     * @return
     */
    public boolean isWithJansi() {
        return withJansi;
    }

    /**
     * If true, this appender will output to a stream which
     *
     * @param withJansi
     * @since 1.0.5
     */
    public void setWithJansi(boolean withJansi) {
        this.withJansi = withJansi;
    }

}