/*******************************************************************************
 * 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.views.tasklist;

import java.net.MalformedURLException;
import java.net.URL;
import java.text.DateFormat;
import java.text.MessageFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.resources.IMarker;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;

import org.eclipse.swt.graphics.Image;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.jface.util.Assert;
import org.eclipse.jface.viewers.IBasicPropertyConstants;

/**
 * Utility class for accessing marker attributes.
 */
class MarkerUtil implements IMarkerConstants {
	
	private static Map imageDescriptors;
	
	private static ImageRegistry imageRegistry = new ImageRegistry();
	
	private static MessageFormat line =
		new MessageFormat(TaskListMessages.getString("TaskList.line")); //$NON-NLS-1$;
		
	private static MessageFormat lineAndLocation =
		new MessageFormat(TaskListMessages.getString("TaskList.lineAndLocation")); //$NON-NLS-1$
	
	static {
		createImageDescriptors();
	}
	
	
	/**
	 * Don't allow instantiation.
	 */
	private MarkerUtil() {
	}

	/**
	 * Creates an image descriptor for the image file referred to by the
	 * given relative path (relative to the icons directory for the plug-in).
	 */
	static ImageDescriptor createImageDescriptor(String relativePath) {
		String iconPath = "icons/full/";//$NON-NLS-1$
		try {
			URL URL_BASIC = TaskList.getPlugin().getDescriptor().getInstallURL();
			URL url = new URL(URL_BASIC, iconPath + relativePath);
			return ImageDescriptor.createFromURL(url);
		} catch (MalformedURLException e) {
			Assert.isTrue(false);
			return null;
		}
	}

	/**
	 * Creates the map of image descriptors.
	 */
	static void createImageDescriptors() {
		String LOCAL = "clcl16/";//$NON-NLS-1$
		String LOCAL_GREY = "elcl16/";//$NON-NLS-1$
		String LOCAL_DISABLED = "dlcl16/";//$NON-NLS-1$
		String OBJ = "obj16/";//$NON-NLS-1$
		
		imageDescriptors = new HashMap(51);
		imageDescriptors.put("header_complete", createImageDescriptor("obj16/header_complete.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("header_priority", createImageDescriptor("obj16/header_priority.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("task", 			createImageDescriptor(OBJ + "taskmrk_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("error", 			createImageDescriptor(OBJ + "error_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("warn", 			createImageDescriptor(OBJ + "warn_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("info", 			createImageDescriptor(OBJ + "info_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("hprio", 			createImageDescriptor(OBJ + "hprio_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("lprio", 			createImageDescriptor(OBJ + "lprio_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("complete_tsk", 	createImageDescriptor(OBJ + "complete_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("incomplete_tsk",	createImageDescriptor(OBJ + "incomplete_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("gotoobj", 		createImageDescriptor(LOCAL + "gotoobj_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("gotoobj_grey", 	createImageDescriptor(LOCAL_GREY + "gotoobj_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("addtsk", 			createImageDescriptor(LOCAL + "addtsk_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("addtsk_grey", 	createImageDescriptor(LOCAL_GREY + "addtsk_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("addtsk_disabled", createImageDescriptor(LOCAL_DISABLED + "addtsk_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showcomplete", 	createImageDescriptor(LOCAL + "showcomplete_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("selected_mode", 	createImageDescriptor(LOCAL + "selected_mode.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("selected_mode_grey", createImageDescriptor(LOCAL_GREY + "selected_mode.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("selected_mode_disabled", createImageDescriptor(LOCAL_DISABLED + "selected_mode.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showchild_mode",	createImageDescriptor(LOCAL + "showchild_mode.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showchild_mode_grey", createImageDescriptor(LOCAL_GREY + "showchild_mode.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showchild_mode_disabled",	createImageDescriptor(LOCAL_DISABLED + "showchild_mode.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showerr_grey", 	createImageDescriptor(LOCAL_GREY + "showerr_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showerr_disabled", createImageDescriptor(LOCAL_DISABLED + "showerr_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showwarn_grey", 	createImageDescriptor(LOCAL_GREY + "showwarn_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showwarn_disabled", createImageDescriptor(LOCAL_DISABLED + "showwarn_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showtsk_grey",	createImageDescriptor(LOCAL_GREY + "showtsk_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("showtsk_disabled", createImageDescriptor(LOCAL_DISABLED + "showtsk_tsk.gif"));//$NON-NLS-2$//$NON-NLS-1$
		imageDescriptors.put("filter", 			createImageDescriptor(LOCAL + "filter_ps.gif"));//$NON-NLS-2$//$NON-NLS-1$
	}

	/**
	 * Returns the ending character offset of the given marker.
	 */
	public static int getCharEnd(IMarker marker) {
		return marker.getAttribute(IMarker.CHAR_END, -1);
	}

	/**
	 * Returns the starting character offset of the given marker.
	 */
	public static int getCharStart(IMarker marker) {
		return marker.getAttribute(IMarker.CHAR_START, -1);
	}

	/**
	 * Returns the icon to be used in the tasklist
	 * for the complete state of a task. Returns null
	 * for markers that are not tasks.
	 */
	public static Image getCompleteImage(IMarker marker) {
		if (isMarkerType(marker, IMarker.TASK)) {
			if (isComplete(marker))
				return getImage("complete_tsk");//$NON-NLS-1$
			else if (!isReadOnly(marker)) // don't show a check box for read-only tasks
				return getImage("incomplete_tsk");//$NON-NLS-1$
		}
		return null;
	}

	/**
	 * Returns the text to be used for the complete state of a task. 
	 * Returns the empty string for markers that are not tasks.
	 */
	public static String getCompleteText(IMarker marker) {
		if (isMarkerType(marker, IMarker.TASK)) {
			if (isComplete(marker)) 
				return TaskListMessages.getString("TaskList.completed"); //$NON-NLS-1$
			else	
				return TaskListMessages.getString("TaskList.notCompleted"); //$NON-NLS-1$
		}
		return ""; //$NON-NLS-1$
	}

	/**
	 * Returns the text to be used for the kind of marker.
	 */
	public static String getKindText(IMarker marker) {
		if (isMarkerType(marker, IMarker.TASK)) {
			return TaskListMessages.getString("TaskList.task"); //$NON-NLS-1$
		}
		switch (getSeverity(marker)) {
			case IMarker.SEVERITY_ERROR:
				return TaskListMessages.getString("TaskList.error"); //$NON-NLS-1$
			case IMarker.SEVERITY_WARNING:
				return TaskListMessages.getString("TaskList.warning"); //$NON-NLS-1$
			case IMarker.SEVERITY_INFO:
				return TaskListMessages.getString("TaskList.info"); //$NON-NLS-1$
		}
		return ""; //$NON-NLS-1$
	}

	/**
	 * Returns the container name if it is defined, or empty string if not.
	 */
	public static String getContainerName(IMarker marker) {
		IPath path = marker.getResource().getFullPath();
		int n = path.segmentCount() - 1; // n is the number of segments in container, not path
		if (n <= 0)
			return ""; //$NON-NLS-1$
		int len = 0;
		for (int i = 0; i < n; ++i)
			len += path.segment(i).length();
		// account for /'s
		if (n > 1)
			len += n-1;
		StringBuffer sb = new StringBuffer(len);
		for (int i = 0; i < n; ++i) {
			if (i != 0)
				sb.append('/');
			sb.append(path.segment(i));
		}
		return sb.toString();
	}
	
	/**
	 * Returns the image with the given key, or <code>null</code> if not found.
	 */
	static Image getImage(String key) {
		Image image = (Image) imageRegistry.get(key);
		if (image == null) {
			ImageDescriptor desc = getImageDescriptor(key);
			if (desc != null) {
				image = desc.createImage(false);
				if (image == null) {
					System.err.println("TaskList: Error creating image for " + key);//$NON-NLS-1$
				}
				imageRegistry.put(key, image);
			}
		}
		return image;
	}

	/**
	 * Returns the image that should be used to visually represent
	 * the marker, based on its type and priority.
	 */
	static public Image getImage(IMarker marker) {
		if (isMarkerType(marker, IMarker.PROBLEM)) {
			switch (getSeverity(marker)) {
				case IMarker.SEVERITY_ERROR:
					return getImage("error");//$NON-NLS-1$
				case IMarker.SEVERITY_WARNING:
					return getImage("warn");//$NON-NLS-1$
				case IMarker.SEVERITY_INFO:
					return getImage("info");//$NON-NLS-1$
			}
		}
		else if (isMarkerType(marker, IMarker.TASK)) {
			return getImage("task");//$NON-NLS-1$
		}
		return null;
	}

	/**
	 * Returns the image descriptor with the given key, or <code>null</code> if not found.
	 */
	static ImageDescriptor getImageDescriptor(String key) {
		ImageDescriptor desc = (ImageDescriptor) imageDescriptors.get(key);
		if (desc == null) {
			System.err.println("TaskList: No image descriptor for " + key); //$NON-NLS-1$
		}
		return desc;
	}

	/**
	 * Returns the text for the line and location column given the marker.
	 */
	public static String getLineAndLocation(IMarker marker) {
		int lineNumber = getLineNumber(marker);
		String location = getLocation(marker);
		return getLineAndLocation(lineNumber, location);
	}

	/**
	 * Returns the text for the line and location column given the line number and location text.
	 */
	public static String getLineAndLocation(int lineNumber, String location) {
		if (lineNumber == -1) {
			if (location.equals("")) {//$NON-NLS-1$
				return "";//$NON-NLS-1$
			}
			else {
				return location;
			}
		}
		else {
			if (location.equals("")) {//$NON-NLS-1$
				return line.format(new Object[] { Integer.toString(lineNumber) });
			}
			else {
				return lineAndLocation.format(new Object[] { Integer.toString(lineNumber), location });
			}
		}
	}

	/**
	 * Returns the line number of the given marker.
	 */
	public static int getLineNumber(IMarker marker) {
		return marker.getAttribute(IMarker.LINE_NUMBER, -1);
	}

	/**
	 * Returns the text for the location field.
	 */
	public static String getLocation(IMarker marker) {
		return marker.getAttribute(IMarker.LOCATION, "");//$NON-NLS-1$
	}

	/**
	 * Returns the message attribute of the given marker,
	 * or the empty string if the message attribute is not defined.
	 */
	public static String getMessage(IMarker marker) {
		return marker.getAttribute(IMarker.MESSAGE, "");//$NON-NLS-1$
	}

	/**
	 * Returns the numeric value of the given string, which is assumed to represent a numeric value.
	 *
	 * @return <code>true</code> if numeric, <code>false</code> if not
	 */
	static public int getNumericValue(String value) {
		boolean negative = false;
		int i = 0;
		int len = value.length();
		
		// skip any leading '#'
		// workaround for 1GCE69U: ITPJCORE:ALL - Java problems should not have '#' in location.
		if (i < len && value.charAt(i) == '#') 
			++i;
	
		if (i < len && value.charAt(i) == '-') {
			negative = true;
			++i;
		}
		
		int result = 0;
		while (i < len) {
			int digit = Character.digit(value.charAt(i++), 10);
			if (digit < 0) {
				return result;
			}
			result = result * 10 + digit;
		}
		if (negative) {
			result = -result;
		}
		return result;
	}

	/**
	 * Returns the priority of the given marker.  Default is PRIORITY_NORMAL.
	 */
	public static int getPriority(IMarker marker) {
		return marker.getAttribute(IMarker.PRIORITY, IMarker.PRIORITY_NORMAL);
	}

	/**
	 * Returns an image that should visually represent marker's priority
	 * in the tasklist.
	 */
	public static Image getPriorityImage(IMarker marker) {
		switch (getPriority(marker)) {
			case IMarker.PRIORITY_HIGH:
				return getImage("hprio");//$NON-NLS-1$
			case IMarker.PRIORITY_NORMAL:
				return null;  // no image for normal priority
			case IMarker.PRIORITY_LOW:
				return getImage("lprio");//$NON-NLS-1$
		}
		return null;
	}

	/**
	 * Returns the text for the given marker's priority.
	 */
	public static String getPriorityText(IMarker marker) {
		if (!isMarkerType(marker, IMarker.TASK))
			return ""; //$NON-NLS-1$
		
		switch (getPriority(marker)) {
			case IMarker.PRIORITY_HIGH:
				return TaskListMessages.getString("TaskList.high"); //$NON-NLS-1$
			case IMarker.PRIORITY_NORMAL:
				return TaskListMessages.getString("TaskList.normal"); //$NON-NLS-1$
			case IMarker.PRIORITY_LOW:
				return TaskListMessages.getString("TaskList.low"); //$NON-NLS-1$
		}
		return ""; //$NON-NLS-1$		
	}

	/**
	 * Implements IProvider interface by supporting a number of
	 * properties required for visual representation of markers
	 * in the tasklist.
	 */
	static public Object getProperty(Object object, String key) {
		IMarker marker = (IMarker) object;
		
		// optimizations:
		// - check properties needed for TaskListLabelProvider first,
		//   then those needed for cell modifiers
		// - use == instead of equals for efficiency
		if (IBasicPropertyConstants.P_IMAGE == key) {
			return getImage(marker);
		}
		if (IMarkerConstants.P_COMPLETE_IMAGE == key) {
			return getCompleteImage(marker);
		}
		if (IMarkerConstants.P_PRIORITY_IMAGE == key) {
			return getPriorityImage(marker);
		}
		if (IMarker.MESSAGE == key) {
			return getMessage(marker);
		}
		if (IMarkerConstants.P_RESOURCE_NAME == key) {
			return getResourceName(marker);
		}
		if (IMarkerConstants.P_CONTAINER_NAME == key) {
			return getContainerName(marker);
		}
		if (IMarkerConstants.P_LINE_AND_LOCATION == key) {
			return getLineAndLocation(marker);
		}
		if (IMarker.PRIORITY == key) {
			// this property is used only by cell editor, where order is High, Normal, Low
			return new Integer(IMarker.PRIORITY_HIGH-getPriority(marker));
		}
		if (IMarker.DONE == key) {
			return isComplete(marker) ? Boolean.TRUE : Boolean.FALSE;
		}
		if (IBasicPropertyConstants.P_TEXT == key) {
			return getMessage(marker);
		}
		return null;
	}

	/**
	 * Returns name if it is defined, or
	 * blank string if not.
	 */
	public static String getResourceName(IMarker marker) {
		return marker.getResource().getName();
	}

	/**
	 * Returns the severity of the given marker.  Default is SEVERITY_WARNING.
	 */
	public static int getSeverity(IMarker marker) {
		return marker.getAttribute(IMarker.SEVERITY, IMarker.SEVERITY_WARNING);
	}

	/**
	 * A helper method that returns true if the given
	 * marker is marked as complete in the tasklist.
	 * Only tasks can be complete.
	 */
	public static boolean isComplete(IMarker marker) {
		return marker.getAttribute(IMarker.DONE, false);
	}

	/**
	 * Returns whether the given marker is editable.
	 * Only tasks which have not been marked as read-only are editable.
	 */
	public static boolean isEditable(IMarker marker) {
		return isMarkerType(marker, IMarker.TASK) && !isReadOnly(marker);
	}

	/**
	 * Returns whether the given marker is of the given type (either directly or indirectly).
	 */
	public static boolean isMarkerType(IMarker marker, String type) {
		try {
			return marker.isSubtypeOf(type);
		}
		catch (CoreException e) {
			return false;
		}
	}

	/**
	 * Returns whether the given marker is read-only.
	 */
	public static boolean isReadOnly(IMarker marker) {
		return !marker.getAttribute(IMarker.USER_EDITABLE, true);
	}

	/**
	 * Returns the creation time of the marker as a string.
	 */
	public static String getCreationTime(IMarker marker) {
		try {
			return DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.MEDIUM).format(new Date(marker.getCreationTime()));
		} catch (CoreException e) {
			return null;
		}
	}
}