AbstractCriteriaLookupManager.java

/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 *
 * 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.
 */

package org.kie.workbench.common.stunner.core.lookup.criteria;

import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.logging.Logger;

import org.kie.workbench.common.stunner.core.lookup.AbstractLookupManager;
import org.kie.workbench.common.stunner.core.lookup.LookupManager;

public abstract class AbstractCriteriaLookupManager<I, T, R extends LookupManager.LookupRequest>
        extends AbstractLookupManager<I, T, R> {

    private static Logger LOGGER = Logger.getLogger(AbstractCriteriaLookupManager.class.getName());

    protected static final String CRITERIA_SEPARATOR = ";";
    protected static final String VALUE_SEPARATOR = "=";
    protected static final String COLLECTION_START_CHAR = "[";
    protected static final String COLLECTION_END_CHAR = "]";
    protected static final String COLLECTION_DELIMITER = ",";

    protected abstract boolean matches(final String key,
                                       final String value,
                                       final I item);

    @Override
    protected boolean matches(final String criteria,
                              final I item) {
        final Map<String, String> criterias = parseCriteria(criteria);
        if (null != criterias) {
            for (final Map.Entry<String, String> entry : criterias.entrySet()) {
                if (!matches(entry.getKey(),
                             entry.getValue(),
                             item)) {
                    return false;
                }
            }
            return true;
        }
        return false;
    }

    public static Map<String, String> parseCriteria(final String criteria) {
        if (null != criteria) {
            final Map<String, String> result = new HashMap<>(criteria.length());
            final String[] criterias = criteria.split(CRITERIA_SEPARATOR);
            for (String c : criterias) {
                final String[] pair = parseCriteriaPair(c);
                if (null != pair) {
                    result.put(pair[0],
                               pair[1]);
                }
            }
            return result;
        }
        return null;
    }

    public static String[] parseCriteriaPair(final String criteria) {
        if (null != criteria) {
            final String[] s = criteria.split(VALUE_SEPARATOR);
            if (s.length == 0) {
                return null;
            }
            if (s.length != 2) {
                throw new IllegalArgumentException("Cannot parse lookup request criteria [pair='" + criteria + "']");
            }
            return new String[]{s[0].trim(), s[1]};
        }
        return null;
    }

    protected Set<String> toSet(final String s) {
        if (s != null && !s.startsWith(COLLECTION_START_CHAR)) {
            return new HashSet<>(0);
        } else if (s != null && s.startsWith(COLLECTION_START_CHAR) && s.endsWith(COLLECTION_END_CHAR)) {
            final String toParse = s.substring(1,
                                               s.length() - 2);
            final String[] parsed = toParse.split(COLLECTION_DELIMITER);
            final HashSet<String> result = new HashSet<>(parsed.length);
            for (String p : parsed) {
                result.add(p.trim());
            }
            return result;
        }
        return null;
    }

    protected static <T> boolean isIntersect(final Collection<T> c1,
                                             final Collection<T> c2) {
        if (c1 == null && c2 == null) {
            return true;
        } else if (c1 == null) {
            return false;
        } else {
            for (T t : c1) {
                if (c2.contains(t)) {
                    return true;
                }
            }
            return false;
        }
    }
}