/*-
 * ============LICENSE_START=======================================================
 * onap
 * ================================================================================
 * Copyright (C) 2016 - 2017 ONAP
 * ================================================================================
 * 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
 * 
 *      http://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.
 * ============LICENSE_END=========================================================
 */

package org.onap.ccsdk.sli.core.utils;

import java.io.File;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Optional;
import org.osgi.framework.FrameworkUtil;

/**
 * Resolves dblib properties files relative to the directory identified by the JRE property
 * <code>dblib.properties</code>.
 */
public class JREFileResolver implements PropertiesFileResolver {

    /**
     * Key for JRE argument representing the configuration directory
     */
    private static final String DBLIB_JRE_PROPERTY_KEY = "dblib.properties";

    private final String successMessage;
    private final Class clazz;

    public JREFileResolver(final String successMessage, final Class clazz) {
        this.successMessage = successMessage;
        this.clazz = clazz;
    }

    /**
     * Parse a properties file location based on JRE argument
     *
     * @return an Optional File containing the location if it exists, or an empty Optional
     */
    @Override
    public Optional<File> resolveFile(final String filename) {
        final URL jreArgumentUrl = FrameworkUtil.getBundle(this.clazz)
                .getResource(DBLIB_JRE_PROPERTY_KEY);
        try {
            if (jreArgumentUrl == null) {
                return Optional.empty();
            }
            final Path dblibPath = Paths.get(jreArgumentUrl.toURI());
            return Optional.of(dblibPath.resolve(filename).toFile());
        } catch(final URISyntaxException e) {
            return Optional.empty();
        }
    }

    @Override
    public String getSuccessfulResolutionMessage() {
        return this.successMessage;
    }
}