/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.maven.tools.plugin.scanner;

import javax.inject.Inject;
import javax.inject.Named;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.maven.plugin.descriptor.InvalidPluginDescriptorException;
import org.apache.maven.plugin.descriptor.MojoDescriptor;
import org.apache.maven.tools.plugin.PluginToolsRequest;
import org.apache.maven.tools.plugin.extractor.ExtractionException;
import org.apache.maven.tools.plugin.extractor.GroupKey;
import org.apache.maven.tools.plugin.extractor.MojoDescriptorExtractor;
import org.apache.maven.tools.plugin.extractor.MojoDescriptorExtractorComparator;
import org.codehaus.plexus.logging.AbstractLogEnabled;
import org.codehaus.plexus.logging.Logger;
import org.codehaus.plexus.logging.console.ConsoleLogger;

/**
 * @author jdcasey
 */
@Named
public class DefaultMojoScanner extends AbstractLogEnabled implements MojoScanner {

    private Map<String, MojoDescriptorExtractor> mojoDescriptorExtractors;

    /**
     * The names of the active extractors
     */
    private Set<String> activeExtractors;

    /**
     * Default constructor
     *
     * @param extractors not null
     */
    @Inject
    public DefaultMojoScanner(Map<String, MojoDescriptorExtractor> extractors) {
        this.mojoDescriptorExtractors = extractors;

        this.enableLogging(new ConsoleLogger(Logger.LEVEL_INFO, "standalone-scanner-logger"));
    }

    /**
     * Empty constructor
     */
    public DefaultMojoScanner() {
        // nop
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void populatePluginDescriptor(PluginToolsRequest request)
            throws ExtractionException, InvalidPluginDescriptorException {
        Logger logger = getLogger();

        int numMojoDescriptors = 0;

        List<MojoDescriptorExtractor> orderedExtractors = getOrderedExtractors();

        logger.debug("Using " + orderedExtractors.size() + " mojo extractors.");

        HashMap<String, Integer> groupStats = new HashMap<>();

        for (MojoDescriptorExtractor extractor : orderedExtractors) {
            GroupKey groupKey = extractor.getGroupKey();
            String extractorId = extractor.getName();

            logger.debug("Applying " + extractorId + " mojo extractor");

            List<MojoDescriptor> extractorDescriptors = extractor.execute(request);

            int extractorDescriptorsCount = extractorDescriptors.size();

            logger.info(extractorId + " mojo extractor found " + extractorDescriptorsCount + " mojo descriptor"
                    + (extractorDescriptorsCount > 1 ? "s" : "") + ".");
            numMojoDescriptors += extractorDescriptorsCount;

            if (extractor.isDeprecated() && extractorDescriptorsCount > 0) {
                logger.warn("");
                logger.warn("Deprecated extractor " + extractorId
                        + " extracted " + extractorDescriptorsCount
                        + " descriptor" + (extractorDescriptorsCount > 1 ? "s" : "")
                        + ". Upgrade your Mojo definitions.");
                if (GroupKey.JAVA_GROUP.equals(groupKey.getGroup())) {
                    logger.warn("You should use Mojo Annotations instead of Javadoc tags.");
                }
                logger.warn("");
            }

            if (groupStats.containsKey(groupKey.getGroup())) {
                groupStats.put(groupKey.getGroup(), groupStats.get(groupKey.getGroup()) + extractorDescriptorsCount);
            } else {
                groupStats.put(groupKey.getGroup(), extractorDescriptorsCount);
            }

            for (MojoDescriptor descriptor : extractorDescriptors) {
                logger.debug("Adding mojo: " + descriptor + " to plugin descriptor.");

                descriptor.setPluginDescriptor(request.getPluginDescriptor());

                request.getPluginDescriptor().addMojo(descriptor);
            }
        }

        logger.debug("Discovered descriptors by groups: " + groupStats);

        if (numMojoDescriptors == 0 && !request.isSkipErrorNoDescriptorsFound()) {
            throw new InvalidPluginDescriptorException("No mojo definitions were found for plugin: "
                    + request.getPluginDescriptor().getPluginLookupKey() + ".");
        }
    }

    /**
     * Returns a list of extractors sorted by {@link MojoDescriptorExtractor#getGroupKey()}s, never {@code null}.
     */
    private List<MojoDescriptorExtractor> getOrderedExtractors() throws ExtractionException {
        Set<String> extractors = activeExtractors;

        if (extractors == null) {
            extractors = new HashSet<>(mojoDescriptorExtractors.keySet());
        }

        ArrayList<MojoDescriptorExtractor> orderedExtractors = new ArrayList<>();
        for (String extractorId : extractors) {
            MojoDescriptorExtractor extractor = mojoDescriptorExtractors.get(extractorId);

            if (extractor == null) {
                throw new ExtractionException("No mojo extractor with '" + extractorId + "' id.");
            }

            orderedExtractors.add(extractor);
        }

        Collections.sort(orderedExtractors, MojoDescriptorExtractorComparator.INSTANCE);

        return orderedExtractors;
    }

    @Override
    public void setActiveExtractors(Set<String> extractors) {
        if (extractors == null) {
            this.activeExtractors = null;
        } else {
            this.activeExtractors = new HashSet<>();

            for (String extractor : extractors) {
                if (extractor != null && !extractor.isEmpty()) {
                    this.activeExtractors.add(extractor);
                }
            }
        }
    }
}