/*
 * Copyright 2015 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.
 * 
 *      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.scanner;

import org.drools.compiler.kie.builder.impl.InternalKieModule;
import org.drools.compiler.kproject.xml.DependencyFilter;
import org.eclipse.aether.artifact.Artifact;
import org.kie.api.builder.KieModule;
import org.kie.api.builder.ReleaseId;
import org.kie.internal.utils.ClassLoaderResolver;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.ProtectionDomain;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;


public class MavenClassLoaderResolver implements ClassLoaderResolver {
    private static final ProtectionDomain  PROTECTION_DOMAIN;
    
    private static final Logger logger = LoggerFactory.getLogger(MavenClassLoaderResolver.class);

    static {
        PROTECTION_DOMAIN = (ProtectionDomain) AccessController.doPrivileged( new PrivilegedAction() {

            public Object run() {
                return MavenClassLoaderResolver.class.getProtectionDomain();
            }
        } );
    }
    

    @Override
    public ClassLoader getClassLoader(KieModule kmodule) {
        ClassLoader parent = Thread.currentThread().getContextClassLoader();
        if (parent == null) {
            parent = ClassLoader.getSystemClassLoader();
        }
        if (parent == null) {
            parent = MavenClassLoaderResolver.class.getClassLoader();
        }

        InternalKieModule internalKModule = (InternalKieModule)kmodule;
        Collection<ReleaseId> jarDependencies = internalKModule.getJarDependencies( DependencyFilter.COMPILE_FILTER );

        if (jarDependencies.isEmpty()) {
            return parent;
        }

        ArtifactResolver resolver = ArtifactResolver.getResolverFor(internalKModule.getPomModel());
        List<URL> urls = new ArrayList<URL>();
        List<ReleaseId> unresolvedDeps = new ArrayList<ReleaseId>();

        for (ReleaseId rid : jarDependencies) {
            try {
                Artifact artifact = resolver.resolveArtifact(rid);
                if( artifact != null ) {
                    File jar = artifact.getFile(); 
                    urls.add( jar.toURI().toURL() );
                } else {
                    logger.error( "Dependency artifact not found for: " + rid );
                    unresolvedDeps.add(rid);
                }
            } catch (MalformedURLException e) {
                throw new RuntimeException(e);
            }
        }

        internalKModule.setUnresolvedDependencies(unresolvedDeps);
        return new URLClassLoader(urls.toArray(new URL[urls.size()]), parent);
    }

}