/*******************************************************************************
 * Copyright (c) 2008, 2011 Sonatype Inc. and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Sonatype Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.tycho.core.osgitools.targetplatform;

import static java.util.Optional.ofNullable;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.maven.ProjectDependenciesResolver;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.ArtifactUtils;
import org.apache.maven.artifact.resolver.AbstractArtifactResolutionException;
import org.apache.maven.artifact.resolver.MultipleArtifactsNotFoundException;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Requirement;
import org.codehaus.plexus.logging.AbstractLogEnabled;
import org.codehaus.plexus.logging.Logger;
import org.eclipse.tycho.ArtifactKey;
import org.eclipse.tycho.ArtifactType;
import org.eclipse.tycho.DefaultArtifactKey;
import org.eclipse.tycho.ReactorProject;
import org.eclipse.tycho.artifacts.DependencyArtifacts;
import org.eclipse.tycho.artifacts.TargetPlatform;
import org.eclipse.tycho.core.DependencyResolver;
import org.eclipse.tycho.core.DependencyResolverConfiguration;
import org.eclipse.tycho.core.TargetPlatformConfiguration;
import org.eclipse.tycho.core.TychoConstants;
import org.eclipse.tycho.core.TychoProject;
import org.eclipse.tycho.core.maven.MavenDependencyCollector;
import org.eclipse.tycho.core.osgitools.AbstractTychoProject;
import org.eclipse.tycho.core.osgitools.BundleReader;
import org.eclipse.tycho.core.osgitools.DefaultReactorProject;
import org.eclipse.tycho.core.osgitools.OsgiManifest;
import org.eclipse.tycho.core.osgitools.OsgiManifestParserException;
import org.eclipse.tycho.model.Feature;

/**
 * Creates target platform based on local Eclipse installation.
 */
@Component(role = DependencyResolver.class, hint = LocalDependencyResolver.ROLE_HINT, instantiationStrategy = "per-lookup")
public class LocalDependencyResolver extends AbstractLogEnabled implements DependencyResolver {

    public static final String ROLE_HINT = "local";

    @Requirement
    private EclipseInstallationLayout layout;

    @Requirement
    private BundleReader manifestReader;

    @Requirement
    private ProjectDependenciesResolver projectDependenciesResolver;

    @Requirement(role = TychoProject.class)
    private Map<String, TychoProject> projectTypes;

    @Requirement
    private BundleReader bundleReader;

    private boolean isSubdir(File parent, File child) {
        return child.getAbsolutePath().startsWith(parent.getAbsolutePath());
    }

    private void addProjects(MavenSession session, DefaultDependencyArtifacts platform) {
        File parentDir = null;

        for (MavenProject project : session.getProjects()) {
            ReactorProject projectProxy = DefaultReactorProject.adapt(project);
            TychoProject dr = projectTypes.get(project.getPackaging());
            if (dr != null) {
                ArtifactKey key = dr.getArtifactKey(projectProxy);

                platform.removeAll(key.getType(), key.getId());

                platform.addReactorArtifact(key, projectProxy, null, null);

                if (parentDir == null || isSubdir(project.getBasedir(), parentDir)) {
                    parentDir = project.getBasedir();
                }
            }
        }
    }

    @Override
    public void setupProjects(MavenSession session, MavenProject project, ReactorProject reactorProject) {
        // everything is done in resolveDependencies
    }

    @Override
    public TargetPlatform computePreliminaryTargetPlatform(MavenSession session, MavenProject project,
            List<ReactorProject> reactorProjects) {
        // everything is done in resolveDependencies
        return null;
    }

    @Override
    public DependencyArtifacts resolveDependencies(MavenSession session, MavenProject project,
            TargetPlatform resolutionContext, List<ReactorProject> reactorProjects,
            DependencyResolverConfiguration resolverConfiguration) {
        DefaultDependencyArtifacts platform = new DefaultDependencyArtifacts(DefaultReactorProject.adapt(project));

        for (File site : layout.getSites()) {
            for (File plugin : layout.getPlugins(site)) {
                ArtifactKey artifactKey = getArtifactKey(session, plugin);

                if (artifactKey != null) {
                    platform.addArtifactFile(artifactKey, plugin, null);
                }
            }

            for (File feature : layout.getFeatures(site)) {
                Feature desc = Feature.loadFeature(feature);
                ArtifactKey key = new DefaultArtifactKey(ArtifactType.TYPE_ECLIPSE_FEATURE, desc.getId(),
                        desc.getVersion());

                platform.addArtifactFile(key, feature, null);
            }
        }

        addProjects(session, platform);
        addDependencies(session, project, platform);

        if (platform.isEmpty()) {
            getLogger().warn("Could not find any bundles or features in " + layout.getLocation());
        }

        return platform;
    }

    private void addDependencies(MavenSession session, MavenProject project, DefaultDependencyArtifacts platform) {
        TargetPlatformConfiguration configuration = (TargetPlatformConfiguration) project
                .getContextValue(TychoConstants.CTX_TARGET_PLATFORM_CONFIGURATION);

        boolean considerPomDependencies = ofNullable(configuration)//
                .map(TargetPlatformConfiguration::getPomDependencies)
                .map(TargetPlatformConfiguration.POM_DEPENDENCIES_CONSIDER::equals)//
                .orElse(false);
        if (!considerPomDependencies)
            return;

        Map<String, MavenProject> projectIds = new HashMap<>(session.getProjects().size() * 2);
        // make a list of reactor projects
        for (MavenProject p : session.getProjects()) {
            String key = ArtifactUtils.key(p.getGroupId(), p.getArtifactId(), p.getVersion());
            projectIds.put(key, p);
        }
        // handle dependencies that are in reactor
        project.getDependencies().stream()//
                .filter(d -> Artifact.SCOPE_COMPILE.equals(d.getScope()))//
                .map(d -> ArtifactUtils.key(d.getGroupId(), d.getArtifactId(), d.getVersion()))//
                .filter(projectIds::containsKey)//
                .map(projectIds::get)//
                .forEach(dependent -> {
                    ArtifactKey artifactKey = getArtifactKey(session, dependent);
                    if (artifactKey != null) {
                        platform.removeAll(artifactKey.getType(), artifactKey.getId());
                        ReactorProject projectProxy = DefaultReactorProject.adapt(dependent);
                        platform.addReactorArtifact(artifactKey, projectProxy, null, null);
                        if (getLogger().isDebugEnabled()) {
                            getLogger().debug("Add Maven project " + artifactKey);
                        }
                    }
                });
        // handle rest of dependencies
        ArrayList<String> scopes = new ArrayList<>();
        scopes.add(Artifact.SCOPE_COMPILE);
        Collection<Artifact> artifacts;
        try {
            artifacts = projectDependenciesResolver.resolve(project, scopes, session);
        } catch (MultipleArtifactsNotFoundException e) {
            Collection<Artifact> missing = new HashSet<>(e.getMissingArtifacts());

            for (Iterator<Artifact> it = missing.iterator(); it.hasNext();) {
                Artifact a = it.next();
                String key = ArtifactUtils.key(a.getGroupId(), a.getArtifactId(), a.getBaseVersion());
                if (projectIds.containsKey(key)) {
                    it.remove();
                }
            }

            if (!missing.isEmpty()) {
                throw new RuntimeException("Could not resolve project dependencies", e);
            }

            artifacts = e.getResolvedArtifacts();
            artifacts.removeAll(e.getMissingArtifacts());
        } catch (AbstractArtifactResolutionException e) {
            throw new RuntimeException("Could not resolve project dependencies", e);
        }
        for (Artifact artifact : artifacts) {
            String key = ArtifactUtils.key(artifact.getGroupId(), artifact.getArtifactId(), artifact.getBaseVersion());
            if (!projectIds.containsKey(key)) {
                File plugin = artifact.getFile();
                ArtifactKey artifactKey = getArtifactKey(session, plugin);

                if (artifactKey != null) {
                    platform.addArtifactFile(artifactKey, plugin, null);
                    if (getLogger().isDebugEnabled()) {
                        getLogger().debug("Add Maven artifact " + artifactKey);
                    }
                }
            }
        }
    }

    public ArtifactKey getArtifactKey(MavenSession session, MavenProject project) {
        OsgiManifest mf;
        try {
            mf = manifestReader.loadManifest(project.getBasedir());
        } catch (OsgiManifestParserException e) {
            return null;
        }
        return mf.toArtifactKey();
    }

    public ArtifactKey getArtifactKey(MavenSession session, File plugin) {
        OsgiManifest mf = manifestReader.loadManifest(plugin);
        ArtifactKey key = mf.toArtifactKey();
        return key;
    }

    public void setLocation(File location) throws IOException {
        layout.setLocation(location.getAbsoluteFile());
    }

    @Override
    public void injectDependenciesIntoMavenModel(MavenProject project, AbstractTychoProject projectType,
            DependencyArtifacts targetPlatform, Logger logger) {
        // walk depencencies for consistency
        projectType.checkForMissingDependencies(project);

        MavenDependencyCollector dependencyCollector = new MavenDependencyCollector(project, bundleReader, logger);
        projectType.getDependencyWalker(project).walk(dependencyCollector);
    }
}