/*
 * Copyright (c) 2017 the original author or authors.
 * 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
 */

package org.eclipse.buildship.core.workspace.internal;

import java.util.ArrayList;
import java.util.Collection;

import org.gradle.tooling.BuildAction;
import org.gradle.tooling.BuildController;
import org.gradle.tooling.model.gradle.GradleBuild;

/**
 * Build action to query a model for all participants in a composite.
 *
 * @param <T> The requested model type
 * @author Donat Csikos
 */
public final class CompositeModelQuery<T> implements BuildAction<Collection<T>> {

    private static final long serialVersionUID = 1L;

    private final Class<T> modelType;

    public CompositeModelQuery(Class<T> modelType) {
        this.modelType = modelType;
    }

    @Override
    public Collection<T> execute(BuildController controller) {
        Collection<T> models = new ArrayList<T>();
        collectRootModels(controller, controller.getBuildModel(), models);
        return models;
    }

    private void collectRootModels(BuildController controller, GradleBuild build, Collection<T> models) {
        models.add(controller.getModel(build.getRootProject(), this.modelType));

        for (GradleBuild includedBuild : build.getIncludedBuilds()) {
            collectRootModels(controller, includedBuild, models);
        }
    }
}