MetacardResourceStatus.java

/**
 * Copyright (c) Codice Foundation
 * <p>
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 * <p>
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */
package ddf.catalog.core.resourcestatus.metacard;

import java.util.List;
import java.util.Objects;
import java.util.Optional;

import org.codice.ddf.configuration.SystemInfo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import ddf.catalog.cache.ResourceCacheInterface;
import ddf.catalog.cache.impl.CacheKey;
import ddf.catalog.data.Metacard;
import ddf.catalog.data.Result;
import ddf.catalog.data.impl.AttributeImpl;
import ddf.catalog.operation.QueryResponse;
import ddf.catalog.operation.ResourceRequest;
import ddf.catalog.operation.impl.ResourceRequestById;
import ddf.catalog.plugin.PluginExecutionException;
import ddf.catalog.plugin.PostQueryPlugin;
import ddf.catalog.plugin.StopProcessingException;
import ddf.catalog.resource.data.ReliableResource;

/**
 * {@link PostQueryPlugin} that checks the {@link ddf.catalog.cache.impl.ResourceCache} for existence
 * of each {@link Metacard}'s related {@link ddf.catalog.resource.Resource} and
 * adds an {@link ddf.catalog.data.Attribute} to each {@link Metacard} in the {@link QueryResponse}.
 */
public class MetacardResourceStatus implements PostQueryPlugin {

    private static final Logger LOGGER = LoggerFactory.getLogger(MetacardResourceStatus.class);

    private static final String INTERNAL_LOCAL_RESOURCE = "internal.local-resource";

    private static final String LOCAL_CONTENT_SCHEME = "content:";

    private ResourceCacheInterface cache;

    public MetacardResourceStatus(ResourceCacheInterface cache) {
        this.cache = cache;
    }

    @Override
    public QueryResponse process(QueryResponse input)
            throws PluginExecutionException, StopProcessingException {
        List<Result> results = input.getResults();

        results.stream()
                .map(Result::getMetacard)
                .filter(Objects::nonNull)
                .forEach(this::addResourceLocalAttribute);

        return input;
    }

    private void addResourceLocalAttribute(Metacard metacard) {
        boolean isResourceLocal = false;
        if (!hasResourceUri(metacard)) {
            isResourceLocal = false;
        } else {
            isResourceLocal = isResourceLocal(metacard);
        }
        metacard.setAttribute(
                new AttributeImpl(INTERNAL_LOCAL_RESOURCE, isResourceLocal));
    }

    private boolean isResourceLocal(Metacard metacard) {
        return (doesSourceIdMatchLocalSiteName(metacard) && isResourceUriLocal(metacard))
                || isResourceCached(metacard, new ResourceRequestById(metacard.getId()));
    }
    
    private boolean isResourceCached(Metacard metacard, ResourceRequest resourceRequest) {
        String key = getCacheKey(metacard, resourceRequest);
        ReliableResource cachedResource = (ReliableResource) cache.getValid(key, metacard);
        return cachedResource != null;
    }

    private boolean hasResourceUri(Metacard metacard) {
        Optional<String> resourceUri = Optional.ofNullable(metacard.getResourceURI())
                .map(uri -> uri.toString());
        return resourceUri.isPresent();
    }

    private boolean isResourceUriLocal(Metacard metacard) {
        return hasResourceUri(metacard) && metacard.getResourceURI()
                .toString()
                .startsWith(LOCAL_CONTENT_SCHEME);
    }

    private boolean doesSourceIdMatchLocalSiteName(Metacard metacard) {
        Optional<String> sourceId = Optional.ofNullable(metacard.getSourceId());

        if (sourceId.isPresent()) {
            String sourceIdLowerCase = sourceId.get()
                    .toLowerCase();
            return sourceIdLowerCase.equals(getLocalSiteName());
        } else {
            LOGGER.debug(
                    "Unable to determine if the source id in metacard {} matches the local site name because the metacard did not contain a source id attribute.",
                    metacard.getId());
            return false;
        }
    }

    private String getCacheKey(Metacard metacard, ResourceRequest resourceRequest) {
        CacheKey cacheKey = new CacheKey(metacard, resourceRequest);
        return cacheKey.generateKey();
    }

    String getLocalSiteName() {
        return SystemInfo.getSiteName()
                .toLowerCase();
    }
}