/*
 * 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 + "]";
 }
}