/*
 * 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.plugin;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.maven.RepositoryUtils;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.model.Plugin;
import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.component.annotations.Component;
import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.graph.DependencyFilter;
import org.eclipse.aether.repository.LocalRepository;
import org.eclipse.aether.repository.RemoteRepository;
import org.eclipse.aether.repository.WorkspaceRepository;

/**
 * @author Igor Fedorenko
 * @author Benjamin Bentmann
 */
@Component(role = PluginArtifactsCache.class)
public class DefaultPluginArtifactsCache implements PluginArtifactsCache {
    /**
     * CacheKey
     */
    protected static class CacheKey implements Key {
        private final Plugin plugin;

        private final WorkspaceRepository workspace;

        private final LocalRepository localRepo;

        private final List<RemoteRepository> repositories;

        private final DependencyFilter filter;

        private final int hashCode;

        public CacheKey(
                Plugin plugin,
                DependencyFilter extensionFilter,
                List<RemoteRepository> repositories,
                RepositorySystemSession session) {
            this.plugin = plugin.clone();
            workspace = RepositoryUtils.getWorkspace(session);
            this.localRepo = session.getLocalRepository();
            this.repositories = new ArrayList<>(repositories.size());
            for (RemoteRepository repository : repositories) {
                if (repository.isRepositoryManager()) {
                    this.repositories.addAll(repository.getMirroredRepositories());
                } else {
                    this.repositories.add(repository);
                }
            }
            this.filter = extensionFilter;

            int hash = 17;
            hash = hash * 31 + CacheUtils.pluginHashCode(plugin);
            hash = hash * 31 + Objects.hashCode(workspace);
            hash = hash * 31 + Objects.hashCode(localRepo);
            hash = hash * 31 + RepositoryUtils.repositoriesHashCode(repositories);
            hash = hash * 31 + Objects.hashCode(extensionFilter);
            this.hashCode = hash;
        }

        @Override
        public String toString() {
            return plugin.getId();
        }

        @Override
        public int hashCode() {
            return hashCode;
        }

        @Override
        public boolean equals(Object o) {
            if (o == this) {
                return true;
            }

            if (!(o instanceof CacheKey)) {
                return false;
            }

            CacheKey that = (CacheKey) o;

            return CacheUtils.pluginEquals(plugin, that.plugin)
                    && Objects.equals(workspace, that.workspace)
                    && Objects.equals(localRepo, that.localRepo)
                    && RepositoryUtils.repositoriesEquals(repositories, that.repositories)
                    && Objects.equals(filter, that.filter);
        }
    }

    protected final Map<Key, CacheRecord> cache = new ConcurrentHashMap<>();

    public Key createKey(
            Plugin plugin,
            DependencyFilter extensionFilter,
            List<RemoteRepository> repositories,
            RepositorySystemSession session) {
        return new CacheKey(plugin, extensionFilter, repositories, session);
    }

    public CacheRecord get(Key key) throws PluginResolutionException {
        CacheRecord cacheRecord = cache.get(key);

        if (cacheRecord != null && cacheRecord.getException() != null) {
            throw cacheRecord.getException();
        }

        return cacheRecord;
    }

    public CacheRecord put(Key key, List<Artifact> pluginArtifacts) {
        Objects.requireNonNull(pluginArtifacts, "pluginArtifacts cannot be null");

        assertUniqueKey(key);

        CacheRecord record = new CacheRecord(Collections.unmodifiableList(new ArrayList<>(pluginArtifacts)));

        cache.put(key, record);

        return record;
    }

    protected void assertUniqueKey(Key key) {
        if (cache.containsKey(key)) {
            throw new IllegalStateException("Duplicate artifact resolution result for plugin " + key);
        }
    }

    public CacheRecord put(Key key, PluginResolutionException exception) {
        Objects.requireNonNull(exception, "exception cannot be null");

        assertUniqueKey(key);

        CacheRecord record = new CacheRecord(exception);

        cache.put(key, record);

        return record;
    }

    public void flush() {
        cache.clear();
    }

    protected static int pluginHashCode(Plugin plugin) {
        return CacheUtils.pluginHashCode(plugin);
    }

    protected static boolean pluginEquals(Plugin a, Plugin b) {
        return CacheUtils.pluginEquals(a, b);
    }

    public void register(MavenProject project, Key cacheKey, CacheRecord record) {
        // default cache does not track record usage
    }
}
