/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.internal.dialogs;

import java.io.IOException;
import java.util.ArrayList;

import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.resource.JFaceColors;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.program.Program;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.internal.AboutItem;
import org.eclipse.ui.internal.WorkbenchMessages;
 
/**
 * Abstract superclass of about dialogs 
 */ 
 
public abstract class ProductInfoDialog extends Dialog{
	private static final String ATT_HTTP = "http://"; //$NON-NLS-1$
	private AboutItem item;
	private boolean webBrowserOpened;
	private String webBrowser = null;
	private Cursor handCursor;
	private Cursor busyCursor;
	private boolean mouseDown = false;
	private boolean dragEvent = false;
	
/**
 * Create an instance of this Dialog
 */
public ProductInfoDialog(Shell parentShell) {
	super(parentShell);
}

/**
 * Adds listeners to the given styled text
 */
protected void addListeners(StyledText styledText) {
	styledText.addMouseListener(new MouseAdapter() {
		public void mouseDown(MouseEvent e) {
			if (e.button != 1) {
				return;
			}
			mouseDown = true;
		}
		public void mouseUp(MouseEvent e) {
			mouseDown = false;
			StyledText text = (StyledText)e.widget;
			int offset = text.getCaretOffset();
			if (dragEvent) {
				// don't activate a link during a drag/mouse up operation
				dragEvent = false;
				if (item != null && item.isLinkAt(offset)) {
					text.setCursor(handCursor);
				}
			} else if (item != null && item.isLinkAt(offset)) {	
				text.setCursor(busyCursor);
				openLink(item.getLinkAt(offset));
				StyleRange selectionRange = getCurrentRange(text);
				text.setSelectionRange(selectionRange.start, selectionRange.length);
				text.setCursor(null);
			}
		}
	});
	
	styledText.addMouseMoveListener(new MouseMoveListener() {
		public void mouseMove(MouseEvent e) {
			// Do not change cursor on drag events
			if (mouseDown) {
				if (!dragEvent) {
					StyledText text = (StyledText)e.widget;
					text.setCursor(null);
				}
				dragEvent = true;
				return;
			}
			StyledText text = (StyledText)e.widget;
			int offset = -1;
			try {
				offset = text.getOffsetAtLocation(new Point(e.x, e.y));
			} catch (IllegalArgumentException ex) {
				// leave value as -1
			}
			if (offset == -1)
				text.setCursor(null);
			else if (item != null && item.isLinkAt(offset)) 
				text.setCursor(handCursor);
			else 
				text.setCursor(null);
		}
	});

	styledText.addTraverseListener(new TraverseListener() {
		public void keyTraversed(TraverseEvent e) {
			StyledText text = (StyledText)e.widget;
			switch (e.detail) {
			case SWT.TRAVERSE_ESCAPE:
				e.doit = true;
				break;
			case SWT.TRAVERSE_TAB_NEXT:
				//Previously traverse out in the backward direction?
				Point nextSelection = text.getSelection();
				int charCount = text.getCharCount();
				if ((nextSelection.x == charCount) && (nextSelection.y == charCount)){
					text.setSelection(0);
				}
				StyleRange nextRange  = findNextRange(text);
				if (nextRange == null) {
					// Next time in start at beginning, also used by 
					// TRAVERSE_TAB_PREVIOUS to indicate we traversed out
					// in the forward direction
					text.setSelection(0);
					e.doit = true;
				} else {
					text.setSelectionRange(nextRange.start, nextRange.length);
					e.doit = true;
					e.detail = SWT.TRAVERSE_NONE;
				}
				break;
			case SWT.TRAVERSE_TAB_PREVIOUS:
				//Previously traverse out in the forward direction?
				Point previousSelection = text.getSelection();
				if ((previousSelection.x == 0) && (previousSelection.y == 0))
					text.setSelection(text.getCharCount());
				StyleRange previousRange = findPreviousRange(text);
				if (previousRange == null) {
					// Next time in start at the end, also used by 
					// TRAVERSE_TAB_NEXT to indicate we traversed out
					// in the backward direction
					text.setSelection(text.getCharCount());
					e.doit = true;
				}
				else {
					text.setSelectionRange(previousRange.start, previousRange.length);
					e.doit = true;
					e.detail = SWT.TRAVERSE_NONE;
				}
				break;
			default:
				break;
			}
		}
	});
	
	//Listen for Tab and Space to allow keyboard navigation
	styledText.addKeyListener(new KeyAdapter() {
		public void keyPressed (KeyEvent event){
			StyledText text = (StyledText)event.widget;
			if(event.character == ' ' || event.character == SWT.CR){
				if(item != null){
					//Be sure we are in the selection
					int offset = text.getSelection().x + 1;

					if (item.isLinkAt(offset)) {	
						text.setCursor(busyCursor);
						openLink(item.getLinkAt(offset));
						StyleRange selectionRange = getCurrentRange(text);
						text.setSelectionRange(selectionRange.start, selectionRange.length);
						text.setCursor(null);
					}
				}
				return;
			}	
		}
	});
}

/**
 * Gets the busy cursor.
 * @return the busy cursor
 */
protected Cursor getBusyCursor() {
	return busyCursor;
}

/**
 * Sets the busy cursor.
 * @param busyCursor the busy cursor
 */
protected void setBusyCursor(Cursor busyCursor) {
	this.busyCursor = busyCursor;
}

/**
 * Gets the hand cursor.
 * @return Returns a hand cursor
 */
protected Cursor getHandCursor() {
	return handCursor;
}

/**
 * Sets the hand cursor.
 * @param handCursor The hand cursor to set
 */
protected void setHandCursor(Cursor handCursor) {
	this.handCursor = handCursor;
}

/**
 * Gets the about item.
 * @return the about item
 */
protected AboutItem getItem() {
	return item;
}

/**
 * Sets the about item.
 * @param item about item
 */
protected void setItem(AboutItem item) {
	this.item = item;
}

/**
 * Find the range of the current selection.
 */
protected StyleRange getCurrentRange(StyledText text){
	StyleRange[] ranges = text.getStyleRanges();
	int currentSelectionEnd = text.getSelection().y;
	int currentSelectionStart = text.getSelection().x;
	
	for (int i = 0; i < ranges.length; i++) {
		if((currentSelectionStart >= ranges[i].start) && 
			(currentSelectionEnd <= (ranges[i].start + ranges[i].length))) {
			return ranges[i];
		}
	}
	return null;
}

/**
 * Find the next range after the current 
 * selection.
 */
protected StyleRange findNextRange(StyledText text){
	StyleRange[] ranges = text.getStyleRanges();
	int currentSelectionEnd = text.getSelection().y;

	for (int i = 0; i < ranges.length; i++) {
		if(ranges[i].start >= currentSelectionEnd)
			return ranges[i];
	}
	return null;
}

/**
 * Find the previous range before the current selection.
 */
protected StyleRange findPreviousRange(StyledText text){
	StyleRange[] ranges = text.getStyleRanges();
	int currentSelectionStart = text.getSelection().x;

	for (int i = ranges.length - 1; i > -1; i--) {
		if((ranges[i].start + ranges[i].length - 1) < currentSelectionStart)
			return ranges[i];
	}
	return null;
}

//TODO: Move browser support from Help system, remove this method
private Process openWebBrowser(String href) throws IOException{
	Process p = null;
	if (webBrowser == null) {
		try {
			webBrowser = "netscape"; //$NON-NLS-1$
			p = Runtime.getRuntime().exec(webBrowser + "  " + href); //$NON-NLS-1$;
		} catch (IOException e) {
			p = null;
			webBrowser = "mozilla"; //$NON-NLS-1$
		}
	}
	 
	if (p==null) {
		try {
			p = Runtime.getRuntime().exec(webBrowser + " " + href); //$NON-NLS-1$;
		} catch (IOException e) {
			p = null;
			throw e;
		}
	}
	return p;
}

/**
 * display an error message
 */
private void openWebBrowserError(Display display) {
	display.asyncExec(new Runnable() {
		public void run() {
			MessageDialog.openError(getShell(), WorkbenchMessages.getString("ProductInfoDialog.errorTitle"), //$NON-NLS-1$
			WorkbenchMessages.getString("ProductInfoDialog.unableToOpenWebBrowser")); //$NON-NLS-1$
		}
	});
}
/**
 * Open a link
 */
protected void openLink(String href) {
	// format the href for an html file (file:///<filename.html>
	// required for Mac only.
	if (href.startsWith("file:")) { //$NON-NLS-1$
		href = href.substring(5);
		while (href.startsWith("/")) { //$NON-NLS-1$
			href = href.substring(1);
		}
		href = "file:///" + href; //$NON-NLS-1$
	}
	final String localHref = href;
	
	final Display d = Display.getCurrent();
	String platform = SWT.getPlatform();
	
	if ("win32".equals(platform)) { //$NON-NLS-1$
		Program.launch(localHref);
	} else if ("carbon".equals(platform)) { //$NON-NLS-1$
		try {
			Runtime.getRuntime().exec("/usr/bin/open " + localHref); //$NON-NLS-1$
		} catch (IOException e) {
			openWebBrowserError(d);
		}
	} else {
		Thread launcher = new Thread("About Link Launcher") {//$NON-NLS-1$
			public void run() {
				try {
					if (webBrowserOpened) {
						Runtime.getRuntime().exec(webBrowser + " -remote openURL(" + localHref + ")"); //$NON-NLS-1$ //$NON-NLS-2$
					} else {
						Process p = openWebBrowser(localHref);
						webBrowserOpened = true;
						try {
							if (p != null)
								p.waitFor();
						} catch (InterruptedException e) {
							openWebBrowserError(d);
						} finally {
							webBrowserOpened = false;
						}
					}
				} catch (IOException e) {
					openWebBrowserError(d);
				}
			}
		};
		launcher.start();
	}
}

/**
 * Sets the styled text's bold ranges
 */
protected void setBoldRanges(StyledText styledText, int[][] boldRanges) {
	for (int i = 0; i < boldRanges.length; i++) {
		StyleRange r = new StyleRange(boldRanges[i][0], boldRanges[i][1], null, null, SWT.BOLD);
		styledText.setStyleRange(r);
	}
}

/**
 * Sets the styled text's link (blue) ranges
 */
protected void setLinkRanges(StyledText styledText, int[][] linkRanges) {
	Color fg = JFaceColors.getHyperlinkText(styledText.getShell().getDisplay());
	for (int i = 0; i < linkRanges.length; i++) {
		StyleRange r = new StyleRange(linkRanges[i][0], linkRanges[i][1], fg, null);
		styledText.setStyleRange(r);
	}
}

/**
 * Scan the contents of the about text
 */
protected AboutItem scan(String s) {
	int max = s.length();
	int i = s.indexOf(ATT_HTTP);
	ArrayList linkRanges = new ArrayList();
	ArrayList links = new ArrayList();
	while (i != -1) {
		int start = i;
		// look for the first whitespace character
		boolean found = false;
		i += ATT_HTTP.length();
		while (!found && i < max) {
			found = Character.isWhitespace(s.charAt(i++));
		}
		if (i!=max) i--;
		linkRanges.add(new int[] {start, i - start});
		links.add(s.substring(start, i));
		i = s.indexOf(ATT_HTTP, i);
	}
	return new AboutItem(
			s,
			(int[][])linkRanges.toArray(new int[linkRanges.size()][2]),
			(String[])links.toArray(new String[links.size()]));
}

}