/**

 * Copyright (c) 2010 Symbian Foundation and/or its subsidiary(-ies).

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of the License "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

 *

 * Initial Contributors:

 * Symbian Foundation - initial contribution.

 * Contributors:

 * Description:

 * Overview:

 * Details:

 * Platforms/Drives/Compatibility:

 * Assumptions/Requirement/Pre-requisites:

 * Failures and causes:

 */

package org.symbian.tools.tmw.core.internal.projects;

import org.eclipse.core.expressions.EvaluationContext;

import org.eclipse.core.expressions.EvaluationResult;

import org.eclipse.core.expressions.Expression;

import org.eclipse.core.expressions.ExpressionConverter;

import org.eclipse.core.resources.IProject;

import org.eclipse.core.runtime.CoreException;

import org.eclipse.core.runtime.IConfigurationElement;

import org.symbian.tools.tmw.core.TMWCore;

import org.symbian.tools.tmw.core.projects.IMTWProject;

import org.symbian.tools.tmw.core.projects.IMTWProjectProvider;

public class ProjectProvider implements IMTWProjectProvider {

    private final IConfigurationElement element;

    private final Expression expression;

    private IMTWProjectProvider provider;

    public ProjectProvider(IConfigurationElement element) throws CoreException {

        this.element = element;

        IConfigurationElement[] children = element.getChildren("enablement");

        if (children.length == 1) {

            expression = ExpressionConverter.getDefault().perform(children[0]);

        } else {

            expression = null;

            if (children.length > 1) {

                TMWCore.log(

                        "Project extension in plugin %s has several <enablement> elements. All expressions will be ignored.",

                        element.getNamespaceIdentifier());

            }

        }

    }

    public IMTWProject create(IProject project) {

        return getProvider().create(project);

    }

    private IMTWProjectProvider getProvider() {

        if (provider == null) {

            try {

                provider = (IMTWProjectProvider) element.createExecutableExtension("class");

            } catch (CoreException e) {

                throw new RuntimeException(e);

            }

        }

        return provider;

    }

    public boolean isSupportedProject(final IProject project) {

        try {

            final EvaluationResult result = expression.evaluate(new EvaluationContext(null, project));

            if (!EvaluationResult.FALSE.equals(result)) {

                return getProvider().isSupportedProject(project);

            }

        } catch (CoreException e) {

            TMWCore.log(null, e);

        }

        return false;

    }

}