/*******************************************************************************
 * Copyright (c) 2015-2018 Skymind, Inc.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Apache License, Version 2.0 which is available 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 ******************************************************************************/

package org.datavec.api.io.labels;

import org.apache.commons.io.FilenameUtils;
import org.datavec.api.writable.Text;
import org.datavec.api.writable.Writable;

import java.io.File;
import java.net.URI;

/**
 * Returns a label derived from the base name of the path. Splits the base name
 * of the path with the given regex pattern, and returns the patternPosition'th
 * element of the array.
 *
 * @author saudet
 */
public class PatternPathLabelGenerator implements PathLabelGenerator {
    protected String pattern; // Pattern to split and segment file name, pass in regex
    protected int patternPosition = 0;

    public PatternPathLabelGenerator(String pattern) {
        this.pattern = pattern;
    }

    public PatternPathLabelGenerator(String pattern, int patternPosition) {
        this.pattern = pattern;
        this.patternPosition = patternPosition;
    }

    @Override
    public Writable getLabelForPath(String path) {
        // Label is in the filename
        return new Text(FilenameUtils.getBaseName(path).split(pattern)[patternPosition]);
    }

    @Override
    public Writable getLabelForPath(URI uri) {
        return getLabelForPath(new File(uri).toString());
    }

    @Override
    public boolean inferLabelClasses() {
        return true;
    }
}
