/*
 * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.lib;

import static java.nio.charset.StandardCharsets.UTF_8;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;

/**
 * A simple progress reporter printing on a stream.
 */
public class TextProgressMonitor extends BatchingProgressMonitor {
	private final Writer out;

	private boolean write;

	/**
	 * Initialize a new progress monitor.
	 */
	public TextProgressMonitor() {
		this(new PrintWriter(new OutputStreamWriter(System.err, UTF_8)));
	}

	/**
	 * Initialize a new progress monitor.
	 *
	 * @param out
	 *            the stream to receive messages on.
	 */
	public TextProgressMonitor(Writer out) {
		this.out = out;
		this.write = true;
	}

	/** {@inheritDoc} */
	@Override
	protected void onUpdate(String taskName, int workCurr) {
		StringBuilder s = new StringBuilder();
		format(s, taskName, workCurr);
		send(s);
	}

	/** {@inheritDoc} */
	@Override
	protected void onEndTask(String taskName, int workCurr) {
		StringBuilder s = new StringBuilder();
		format(s, taskName, workCurr);
		s.append("\n"); //$NON-NLS-1$
		send(s);
	}

	private void format(StringBuilder s, String taskName, int workCurr) {
		s.append("\r"); //$NON-NLS-1$
		s.append(taskName);
		s.append(": "); //$NON-NLS-1$
		while (s.length() < 25)
			s.append(' ');
		s.append(workCurr);
	}

	/** {@inheritDoc} */
	@Override
	protected void onUpdate(String taskName, int cmp, int totalWork, int pcnt) {
		StringBuilder s = new StringBuilder();
		format(s, taskName, cmp, totalWork, pcnt);
		send(s);
	}

	/** {@inheritDoc} */
	@Override
	protected void onEndTask(String taskName, int cmp, int totalWork, int pcnt) {
		StringBuilder s = new StringBuilder();
		format(s, taskName, cmp, totalWork, pcnt);
		s.append("\n"); //$NON-NLS-1$
		send(s);
	}

	private void format(StringBuilder s, String taskName, int cmp,
			int totalWork, int pcnt) {
		s.append("\r"); //$NON-NLS-1$
		s.append(taskName);
		s.append(": "); //$NON-NLS-1$
		while (s.length() < 25)
			s.append(' ');

		String endStr = String.valueOf(totalWork);
		String curStr = String.valueOf(cmp);
		while (curStr.length() < endStr.length())
			curStr = " " + curStr; //$NON-NLS-1$
		if (pcnt < 100)
			s.append(' ');
		if (pcnt < 10)
			s.append(' ');
		s.append(pcnt);
		s.append("% ("); //$NON-NLS-1$
		s.append(curStr);
		s.append("/"); //$NON-NLS-1$
		s.append(endStr);
		s.append(")"); //$NON-NLS-1$
	}

	private void send(StringBuilder s) {
		if (write) {
			try {
				out.write(s.toString());
				out.flush();
			} catch (IOException err) {
				write = false;
			}
		}
	}
}