/*******************************************************************************
 * Copyright (c) 2004, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.ui.internal.intro.impl.model.loader;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.ui.internal.intro.impl.model.IntroStandbyContentPart;
import org.eclipse.ui.internal.intro.impl.model.IntroURLAction;
import org.eclipse.ui.internal.intro.impl.util.Log;
import org.eclipse.ui.internal.intro.impl.util.Util;

/**
 * Class for handling all shared Intro Config Extensions. These are StandbyPart
 * and Command contributions. Once defined these contributions are visible by
 * all intro configs.
 */

public class SharedConfigExtensionsManager {

    private IExtensionRegistry registry;

	// Holds all standbyPart extensions
	private Map<String, IntroStandbyContentPart> standbyParts = new HashMap<>();

	// Holds all command extensions
	private Map<String, IntroURLAction> commands = new HashMap<>();

    /*
     * Prevent creation.
     */
    protected SharedConfigExtensionsManager(IExtensionRegistry registry) {
        this.registry = registry;
    }

    /**
     * Loads all shared config extennsions (ie: standby parts and commands.
     */
    protected void loadSharedConfigExtensions() {
        // simply create model classes for all standbyPart elements under a
        // configExtension.

        long start = 0;
        // if we need to log performance, capture time.
        if (Log.logPerformance)
            start = System.currentTimeMillis();

        IConfigurationElement[] configExtensionElements = registry
            .getConfigurationElementsFor(BaseExtensionPointManager.CONFIG_EXTENSION);

        if (Log.logPerformance)
            Util.logPerformanceTime(
                "quering registry for configExtensions took: ", start); //$NON-NLS-1$

        for (int i = 0; i < configExtensionElements.length; i++) {
            IConfigurationElement element = configExtensionElements[i];
            if (!ModelLoaderUtil.isValidElementName(element,
                IntroStandbyContentPart.TAG_STANDBY_CONTENT_PART)
                    && !ModelLoaderUtil.isValidElementName(element,
                        IntroURLAction.TAG_ACTION))
                // if extension is not a standbypart or command, ignore.
                continue;
            createModelClass(element);
        }
    }


    /**
     * Create an intro standby part or an intro command model class.
     *
     * @param element
     */
    private void createModelClass(IConfigurationElement element) {
        if (element.getName().equals(
            IntroStandbyContentPart.TAG_STANDBY_CONTENT_PART)) {
            IntroStandbyContentPart standbyPartContent = new IntroStandbyContentPart(
                element);
            if (standbyPartContent.getId() == null)
                // no id, ignore.
                return;
            standbyParts.put(standbyPartContent.getId(), standbyPartContent);
        } else {
            IntroURLAction introURLCommand = new IntroURLAction(element);
            if (introURLCommand.getName() == null
                    || introURLCommand.getReplaceValue() == null)
                // no name or resolvedValue, ignore.
                return;
            commands.put(introURLCommand.getName(), introURLCommand);
        }
    }



    /**
     * @return Returns a standbyPart basd on its registred id.
     */
    public IntroStandbyContentPart getStandbyPart(String partId) {
        if (partId == null)
            return null;
        return standbyParts.get(partId);
    }

    /**
     * @return Returns the command from its name.
     */
    public IntroURLAction getCommand(String commandName) {
        if (commandName == null)
            return null;
        return commands.get(commandName);
    }

}
