Copyright (c) 2015 Google Inc 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:
    John Glassmyer  - import group sorting is broken - https://bugs.eclipse.org/430303
/*******************************************************************************
 * Copyright (c) 2015 Google Inc 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:
 *     John Glassmyer <jogl@google.com> - import group sorting is broken - https://bugs.eclipse.org/430303
 *******************************************************************************/
package org.eclipse.jdt.internal.core.dom.rewrite.imports;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

Totally sorts new and existing imports together, discarding the order of existing imports
and omitting duplicate entries.
/**
 * Totally sorts new and existing imports together, discarding the order of existing imports
 * and omitting duplicate entries.
 */
final class ReorderingImportAdder implements ImportAdder {
	private final Comparator<ImportName> importComparator;

	ReorderingImportAdder(Comparator<ImportName> importComparator) {
		this.importComparator = importComparator;
	}

	@Override
	public List<ImportName> addImports(Collection<ImportName> existingImports, Collection<ImportName> importsToAdd) {
		int setCapacity = 2 * (existingImports.size() + importsToAdd.size());
		Set<ImportName> uniqueImportsWithAdditions = new HashSet<ImportName>(setCapacity);
		uniqueImportsWithAdditions.addAll(existingImports);
		uniqueImportsWithAdditions.addAll(importsToAdd);

		List<ImportName> sortedImports = new ArrayList<>(uniqueImportsWithAdditions);
		Collections.sort(sortedImports, this.importComparator);

		return sortedImports;
	}
}