/*******************************************************************************
 * Copyright (c) 2000, 2005 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.ui.views.tasklist;

import java.util.ArrayList;
import java.util.HashMap;

import org.eclipse.core.resources.IMarker;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.Platform;

/**
 * Maintains a model of all known marker types.
 */
class MarkerTypesModel {
    /**
     * Maps from marker type id to MarkerType.
     */
    private HashMap types;

    /**
     * Creates a new marker types model.
     */
    public MarkerTypesModel() {
        types = readTypes();
    }

    /**
     * Returns the marker type with the given id, or <code>null</code> if there is no such marker type.
     */
    public MarkerType getType(String id) {
        return (MarkerType) types.get(id);
    }

    /**
     * Returns all known marker types.
     */
    public MarkerType[] getTypes() {
        MarkerType[] result = new MarkerType[types.size()];
        types.values().toArray(result);
        return result;
    }

    /**
     * Returns the label for the given marker type.
     * Workaround until we have labels in XML.
     */
    private String getWellKnownLabel(String type) {
        if (type.equals(IMarker.PROBLEM))
            return "Problem";//$NON-NLS-1$
        if (type.equals(IMarker.TASK))
            return "Task";//$NON-NLS-1$
        if (type.equals("org.eclipse.jdt.core.problem"))//$NON-NLS-1$
            return "Java Problem";//$NON-NLS-1$
        return type;
    }

    /**
     * Reads the marker types from the registry.
     */
    private HashMap readTypes() {
        HashMap types = new HashMap();
        IExtensionPoint point = Platform.getExtensionRegistry().getExtensionPoint(
                ResourcesPlugin.PI_RESOURCES, ResourcesPlugin.PT_MARKERS);
        if (point != null) {
            // Gather all registered marker types.
            IExtension[] extensions = point.getExtensions();
            for (int i = 0; i < extensions.length; ++i) {
                IExtension ext = extensions[i];
                String id = ext.getUniqueIdentifier();
                String label = ext.getLabel();
                if (label.equals("")) {//$NON-NLS-1$
                    label = getWellKnownLabel(id);
                }
                ArrayList supersList = new ArrayList();
                IConfigurationElement[] configElements = ext
                        .getConfigurationElements();
                for (int j = 0; j < configElements.length; ++j) {
                    IConfigurationElement elt = configElements[j];
                    if (elt.getName().equalsIgnoreCase("super")) {//$NON-NLS-1$
                        String sup = elt.getAttribute("type");//$NON-NLS-1$
                        if (sup != null) {
                            supersList.add(sup);
                        }
                    }
                }
                String[] superTypes = new String[supersList.size()];
                supersList.toArray(superTypes);
                MarkerType type = new MarkerType(this, id, label, superTypes);
                types.put(id, type);
            }
        }
        return types;
    }
}