/* Licensed 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.activiti.spring.autodeployment;

import org.activiti.engine.ActivitiException;
import org.activiti.engine.RepositoryService;
import org.activiti.engine.repository.DeploymentBuilder;
import org.springframework.core.io.Resource;

import java.io.IOException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.zip.ZipInputStream;

/**
 * Implementation of {@link AutoDeploymentStrategy} that performs a separate
 * deployment for each set of {@link Resource}s that share the same parent
 * folder. The namehint is used to prefix the names of deployments. If the
 * parent folder for a {@link Resource} cannot be determined, the resource's
 * name is used.
 *
 * @author Tiese Barrell
 */
public class ResourceParentFolderAutoDeploymentStrategy extends AbstractAutoDeploymentStrategy {

    /**
     * The deployment mode this strategy handles.
     */
    public static final String DEPLOYMENT_MODE = "resource-parent-folder";

    private static final String DEPLOYMENT_NAME_PATTERN = "%s.%s";

    @Override
    protected String getDeploymentMode() {
        return DEPLOYMENT_MODE;
    }

    @Override
    public void deployResources(final String deploymentNameHint, final Resource[] resources, final RepositoryService repositoryService) {

        // Create a deployment for each distinct parent folder using the name hint
        // as a prefix
        final Map<String, Set<Resource>> resourcesMap = createMap(resources);

        for (final Entry<String, Set<Resource>> group : resourcesMap.entrySet()) {

            final String deploymentName = determineDeploymentName(deploymentNameHint, group.getKey());

            final DeploymentBuilder deploymentBuilder = repositoryService.createDeployment().enableDuplicateFiltering().name(deploymentName);

            for (final Resource resource : group.getValue()) {
                final String resourceName = determineResourceName(resource);

                try {
                    if (resourceName.endsWith(".bar") || resourceName.endsWith(".zip") || resourceName.endsWith(".jar")) {
                        deploymentBuilder.addZipInputStream(new ZipInputStream(resource.getInputStream()));
                    } else {
                        deploymentBuilder.addInputStream(resourceName, resource.getInputStream());
                    }
                } catch (IOException e) {
                    throw new ActivitiException("couldn't auto deploy resource '" + resource + "': " + e.getMessage(), e);
                }
            }
            deploymentBuilder.deploy();
        }

    }

    private Map<String, Set<Resource>> createMap(final Resource[] resources) {
        final Map<String, Set<Resource>> resourcesMap = new HashMap<String, Set<Resource>>();

        for (final Resource resource : resources) {
            final String parentFolderName = determineGroupName(resource);
            if (resourcesMap.get(parentFolderName) == null) {
                resourcesMap.put(parentFolderName, new HashSet<Resource>());
            }
            resourcesMap.get(parentFolderName).add(resource);
        }
        return resourcesMap;
    }

    private String determineGroupName(final Resource resource) {
        String result = determineResourceName(resource);
        try {
            if (resourceParentIsDirectory(resource)) {
                result = resource.getFile().getParentFile().getName();
            }
        } catch (IOException e) {
            // no-op, fallback to resource name
        }
        return result;
    }

    private boolean resourceParentIsDirectory(final Resource resource) throws IOException {
        return resource.getFile() != null && resource.getFile().getParentFile() != null && resource.getFile().getParentFile().isDirectory();
    }

    private String determineDeploymentName(final String deploymentNameHint, final String groupName) {
        return String.format(DEPLOYMENT_NAME_PATTERN, deploymentNameHint, groupName);
    }
}