/*

 * Copyright (c) 2004, 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 sun.net;

import java.net.URL;

/**

 * ProgressSource represents the source of progress changes.

 *

 * @author Stanley Man-Kit Ho

 */

public class ProgressSource

{

    public enum State { NEW, CONNECTED, UPDATE, DELETE };

    // URL

    private URL url;

    // URL method

    private String method;

    // Content type

    private String contentType;

    // bytes read

    private long progress = 0;

    // last bytes read

    private long lastProgress = 0;

    //bytes expected

    private long expected = -1;

    // the last thing to happen with this source

    private State state;

    // connect flag

    private boolean connected = false;

    // threshold for notification

    private int threshold = 8192;

    // progress monitor

    private ProgressMonitor progressMonitor;

    /**

     * Construct progress source object.

     */

    public ProgressSource(URL url, String method) {

        this(url, method, -1);

    }

    /**

     * Construct progress source object.

     */

    public ProgressSource(URL url, String method, long expected)  {

        this.url = url;

        this.method = method;

        this.contentType = "content/unknown";

        this.progress = 0;

        this.lastProgress = 0;

        this.expected = expected;

        this.state = State.NEW;

        this.progressMonitor = ProgressMonitor.getDefault();

        this.threshold = progressMonitor.getProgressUpdateThreshold();

    }

    public boolean connected() {

        if (!connected) {

            connected = true;

            state = State.CONNECTED;

            return false;

        }

        return true;

    }

    /**

     * Close progress source.

     */

    public void close() {

        state = State.DELETE;

    }

    /**

     * Return URL of progress source.

     */

    public URL getURL() {

        return url;

    }

    /**

     * Return method of URL.

     */

    public String getMethod()  {

        return method;

    }

    /**

     * Return content type of URL.

     */

    public String getContentType()  {

        return contentType;

    }

    // Change content type

    public void setContentType(String ct)  {

        contentType = ct;

    }

    /**

     * Return current progress.

     */

    public long getProgress()  {

        return progress;

    }

    /**

     * Return expected maximum progress; -1 if expected is unknown.

     */

    public long getExpected() {

        return expected;

    }

    /**

     * Return state.

     */

    public State getState() {

        return state;

    }

    /**

     * Begin progress tracking.

     */

    public void beginTracking() {

        progressMonitor.registerSource(this);

    }

    /**

     * Finish progress tracking.

     */

    public void finishTracking() {

        progressMonitor.unregisterSource(this);

    }

    /**

     * Update progress.

     */

    public void updateProgress(long latestProgress, long expectedProgress) {

        lastProgress = progress;

        progress = latestProgress;

        expected = expectedProgress;

        if (connected() == false)

            state = State.CONNECTED;

        else

            state = State.UPDATE;

        // The threshold effectively divides the progress into

        // different set of ranges:

        //

        //      Range 0: 0..threshold-1,

        //      Range 1: threshold .. 2*threshold-1

        //      ....

        //      Range n: n*threshold .. (n+1)*threshold-1

        //

        // To determine which range the progress belongs to, it

        // would be calculated as follow:

        //

        //      range number = progress / threshold

        //

        // Notification should only be triggered when the current

        // progress and the last progress are in different ranges,

        // i.e. they have different range numbers.

        //

        // Using this range scheme, notification will be generated

        // only once when the progress reaches each range.

        //

        if (lastProgress / threshold != progress / threshold)   {

            progressMonitor.updateProgress(this);

        }

        // Detect read overrun

        if (expected != -1) {

            if (progress >= expected && progress != 0)

                close();

        }

    }

    public Object clone() throws CloneNotSupportedException {

        return super.clone();

    }

    public String toString()    {

        return getClass().getName() + "[url=" + url + ", method=" + method + ", state=" + state

            + ", content-type=" + contentType + ", progress=" + progress + ", expected=" + expected + "]";

    }

}