/*******************************************************************************
 * Copyright (c) 2006, 2007 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.pde.internal.ui.util;

import java.util.HashSet;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;

/**
 * PDELabelUtility
 *
 */
public class PDELabelUtility {

	/**
	 * Get the field label text from the label widget created before the
	 * control (assumption).  Use this method when the control's label is
	 * variable or if the label's text is set elsewhere.  Note:  Hyperlink 
	 * label text will not be detected.
	 * @param control
	 * @return
	 */
	public static String getFieldLabel(Control control) {
		// Note:  Does not handle hyperlink labels

		// Get the children of the control's parent
		// The control itself should be in there
		// Assuming the control's label is in there as well
		Control[] controls = control.getParent().getChildren();
		// Ensure has controls
		if (controls.length == 0) {
			return null;
		}
		// Me = control
		// Track the index of myself 
		int myIndex = -1;
		// Linearly search controls for myself
		for (int i = 0; i < controls.length; i++) {
			if (controls[i] == control) {
				// Found myself
				myIndex = i;
				break;
			}
		}
		// Ensure I was found and am not the first widget
		if (myIndex <= 0) {
			return null;
		}
		// Assume label is the control created before me
		int labelIndex = myIndex - 1;
		// Ensure the label index points to a label
		if ((controls[labelIndex] instanceof Label) == false) {
			return null;
		}
		// Get the label text
		String labelText = ((Label) controls[labelIndex]).getText();
		// Get rid of the trailing colon (if any)
		int colonIndex = labelText.indexOf(':');
		if (colonIndex >= 0) {
			labelText = labelText.replaceAll(":", ""); //$NON-NLS-1$ //$NON-NLS-2$
		}
		// Get rid of mnemonics (if any)
		int ampIndex = labelText.indexOf('&');
		if (ampIndex >= 0) {
			labelText = labelText.replaceAll("&", ""); //$NON-NLS-1$ //$NON-NLS-2$
		}

		return labelText;
	}

	/**
	 * @param qualification
	 * @param message
	 * @return
	 */
	public static String qualifyMessage(String qualification, String message) {
		StringBuffer buffer = new StringBuffer();
		buffer.append(qualification);
		buffer.append(':');
		buffer.append(' ');
		buffer.append(message);
		return buffer.toString();
	}

	/**
	 * @param base
	 * @param set
	 */
	private static void addNumberToBase(StringBuffer base, boolean bracketed, HashSet set) {
		if (set.size() > 0) {
			// Limit on the number of auto-generated item numbers to check for
			int limit = 100;
			// Check the set for the numbers encountered and generate the 
			// lowest number accordingly
			if (set.contains(new Integer(0)) == false) {
				// Use base
			} else {
				for (int x = 1; x < limit; x++) {
					// Check if the number was already used to auto-generate an
					// existing item
					if (set.contains(new Integer(x)) == false) {
						if (bracketed)
							base.append(" ("); //$NON-NLS-1$
						base.append(x);
						if (bracketed)
							base.append(")"); //$NON-NLS-1$
						break;
					}
				}
			}
		}
	}

	/**
	 * @param base
	 * @param set
	 * @param title
	 */
	private static void compareTitleWithBase(String base, boolean bracketed, HashSet set, String title) {
		// Check to see it the name starts with the prefix
		if (title.toLowerCase().startsWith(base.toLowerCase())) {
			// with brackets add on is: space, (, #, )
			int minSizeNumAddOn = 4;
			if (!bracketed)
				// without brackets and space add on is just number
				minSizeNumAddOn = 1;
			// We found a possible auto-generated name
			// Determine number
			if (title.length() >= (base.length() + minSizeNumAddOn)) {
				String numPart;
				if (bracketed && title.charAt(base.length()) == ' ') {
					// We skipped the space since we already checked
					numPart = title.substring(base.length() + 1);
				} else if (!bracketed) {
					// without brackets, the numPart is everything after the prefix
					numPart = title.substring(base.length());
				} else {
					// We are using brackets and there was no space
					return;
				}
				if (bracketed) {
					if (numPart.charAt(0) == '(') {
						// We are using brackets and confirmed that the open bracket exists
						// move on to just the number part
						numPart = numPart.substring(1);
					} else {
						// We are using brackets and there is no opening bracket
						return;
					}
				}
				// We found an auto-generated name
				StringBuffer buffer = new StringBuffer();
				// Parse the number between the brackets
				for (int j = 0; j < numPart.length(); j++) {
					char current = numPart.charAt(j);
					// Make sure its a digit
					if (Character.isDigit(current)) {
						buffer.append(current);
					} else {
						if (!bracketed || numPart.charAt(j) != ')' || j != numPart.length() - 1) {
							// without brackets, a non digits means this will not conflict
							// with brackets, anything other than a ')' means this will not conflict
							// with brackets, if this is not the last character it will not conflict
							return;
						}
						// if all conditions passed, this is the last loop, no need to break
					}
				}
				// Convert the number we found into an actual number
				if (buffer.length() > 0) {
					set.add(new Integer(buffer.toString()));
				}

			} else {
				// No number to parse
				// Assume it is just base
				set.add(new Integer(0));
			}
		}
	}

	/**
	 * @return
	 */
	public static String generateName(String[] names, String base) {
		return generateName(names, base, true);
	}

	/**
	 * <p>Generates a name that does not conflict with any of the given names with one of two forms:
	 * <ol>
"<base> (#)"
"<base>#"
	 * The number will be omitted if the base name alone is available.</p>
	 * 
	 * @param names
	 * 			the existing names that should not be conflicted
	 * @param base
	 * 			the base name to add numbers to
	 * @param bracketed
	 * 			if true use the first form, otherwise use the second
	 * @return
	 * 			the non-conflicting name
	 */
	public static String generateName(String[] names, String base, boolean bracketed) {
		StringBuffer result = new StringBuffer(base);
		// Used to track auto-generated numbers used
		HashSet set = new HashSet();

		// Linear search O(n).  
		// Performance hit unnoticeable because number of items per cheatsheet
		// should be minimal.
		for (int i = 0; i < names.length; i++) {
			PDELabelUtility.compareTitleWithBase(base, bracketed, set, names[i]);
		}
		// Add an auto-generated number
		PDELabelUtility.addNumberToBase(result, bracketed, set);

		return result.toString();
	}

	// Gets the base from a name that was generated by the generateName method.
	public static String getBaseName(String name, boolean bracketed) {
		String result = name;
		if (bracketed) {
			if (result.charAt(result.length() - 1) != ')')
				return name;
			result = result.substring(0, result.length() - 1);
		}
		while (Character.isDigit(result.charAt(result.length() - 1)))
			result = result.substring(0, result.length() - 1);
		if (bracketed) {
			if (!result.substring(result.length() - 2).equals(" (")) //$NON-NLS-1$
				return name;
			result = result.substring(0, result.length() - 2);
		}
		return result;
	}
}