/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Other licenses:
 * -----------------------------------------------------------------------------
 * Commercial licenses for this work are available. These replace the above
 * Apache-2.0 license and offer limited warranties, support, maintenance, and
 * commercial database integrations.
 *
 * For more information, please visit: https://www.jooq.org/legal/licensing
 *
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 *
 */
package org.jooq.codegen;

import java.io.File;
import java.io.FilenameFilter;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.stream.Stream;

/**
 * A cache for directories and their contents.
 *
 * @author Lukas Eder
 */
public final class Files {

    private final Map<File, String[]> lists;
    private final Set<File> mkdirs;

    public Files() {
        this.lists = new HashMap<>();
        this.mkdirs = new HashSet<>();
    }

    public final String[] list(File dir, FilenameFilter filter) {
        return Stream
            .of(lists.computeIfAbsent(dir, File::list))
            .filter(e -> filter.accept(dir, e))
            .toArray(String[]::new);
    }

    public final void mkdirs(File dir) {
        if (mkdirs.add(dir))
            dir.mkdirs();
    }
}
