/*
 * RHQ Management Platform
 * Copyright (C) 2005-2009 Red Hat, Inc.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation, and/or the GNU Lesser
 * General Public License, version 2.1, also as published by the Free
 * Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License and the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * and the GNU Lesser General Public License along with this program;
 * if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

package org.rhq.plugins.apache;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.rhq.augeas.AugeasComponent;
import org.rhq.augeas.node.AugeasNode;
import org.rhq.augeas.tree.AugeasTree;
import org.rhq.core.domain.configuration.Configuration;
import org.rhq.core.domain.configuration.ConfigurationUpdateStatus;
import org.rhq.core.domain.configuration.definition.ConfigurationDefinition;
import org.rhq.core.domain.measurement.AvailabilityType;
import org.rhq.core.pluginapi.configuration.ConfigurationFacet;
import org.rhq.core.pluginapi.configuration.ConfigurationUpdateReport;
import org.rhq.core.pluginapi.inventory.DeleteResourceFacet;
import org.rhq.core.pluginapi.inventory.InvalidPluginConfigurationException;
import org.rhq.core.pluginapi.inventory.ResourceComponent;
import org.rhq.core.pluginapi.inventory.ResourceContext;
import org.rhq.plugins.apache.mapping.ApacheAugeasMapping;
import org.rhq.plugins.apache.util.AugeasNodeSearch;

/**
 * Component for configuring the &lt;Directory&gt; and underlying directives
 * inside Apache configuration.
 * 
 * @author Lukas Krejci
 */
public class ApacheDirectoryComponent implements ResourceComponent<ApacheVirtualHostServiceComponent>,
    ConfigurationFacet, DeleteResourceFacet {

    private final Log log = LogFactory.getLog(this.getClass());
    public static final String REGEXP_PROP = "regexp";
    public static final String DIRECTORY_DIRECTIVE = "<Directory";

    private ResourceContext<ApacheVirtualHostServiceComponent> resourceContext;

    public void start(ResourceContext<ApacheVirtualHostServiceComponent> context)
        throws InvalidPluginConfigurationException, Exception {
        resourceContext = context;
    }

    public void stop() {
    }

    public AvailabilityType getAvailability() {
        return AvailabilityType.UP;
    }

    public Configuration loadResourceConfiguration() throws Exception {
        if (!isAugeasEnabled()) {
            throw new IllegalStateException(ApacheServerComponent.CONFIGURATION_NOT_SUPPORTED_ERROR_MESSAGE);            
        }
        
        ApacheVirtualHostServiceComponent parentVirtualHost = resourceContext.getParentResourceComponent();

        AugeasComponent comp = getAugeas();
        try {
            AugeasTree tree = comp.getAugeasTree(ApacheServerComponent.AUGEAS_HTTP_MODULE_NAME);
            ConfigurationDefinition resourceConfigDef = resourceContext.getResourceType()
                .getResourceConfigurationDefinition();

            AugeasNode virtualHostNode = parentVirtualHost.getNode(tree);
            ApacheAugeasMapping mapping = new ApacheAugeasMapping(tree);
            return mapping.updateConfiguration(getNode(virtualHostNode), resourceConfigDef);
        } finally {
            comp.close();
        }
    }

    public void updateResourceConfiguration(ConfigurationUpdateReport report) {
        if (!isAugeasEnabled()) {
            report.setStatus(ConfigurationUpdateStatus.FAILURE);
            report.setErrorMessage(ApacheServerComponent.CONFIGURATION_NOT_SUPPORTED_ERROR_MESSAGE);
            return;
        }
        
        AugeasComponent comp = getAugeas();
        AugeasTree tree = null;
        try {
            tree = comp.getAugeasTree(ApacheServerComponent.AUGEAS_HTTP_MODULE_NAME);
            ConfigurationDefinition resourceConfigDef = resourceContext.getResourceType()
                .getResourceConfigurationDefinition();
            ApacheAugeasMapping mapping = new ApacheAugeasMapping(tree);
            AugeasNode directoryNode = getNode(tree.getRootNode());
            mapping.updateAugeas(directoryNode, report.getConfiguration(), resourceConfigDef);
            tree.save();

            report.setStatus(ConfigurationUpdateStatus.SUCCESS);
            log.info("Apache configuration was updated");

            resourceContext.getParentResourceComponent().finishConfigurationUpdate(report);
        } catch (Exception e) {
            if (tree != null)
                log.error("Augeas failed to save configuration " + tree.summarizeAugeasError());
            else
                log.error("Augeas failed to save configuration", e);
            report.setStatus(ConfigurationUpdateStatus.FAILURE);
        } finally {
            comp.close();
        }
    }

    public void deleteResource() throws Exception {
        if (!isAugeasEnabled()) {
            throw new IllegalStateException(ApacheServerComponent.CONFIGURATION_NOT_SUPPORTED_ERROR_MESSAGE);
        }
        
        ApacheVirtualHostServiceComponent parentVirtualHost = resourceContext.getParentResourceComponent();
        
        AugeasComponent comp = getAugeas();

        try {
            AugeasTree tree = comp.getAugeasTree(ApacheServerComponent.AUGEAS_HTTP_MODULE_NAME);
            AugeasNode virtualHostNode = parentVirtualHost.getNode(tree);

            AugeasNode myNode = getNode(virtualHostNode);

            if (myNode != null) {
                tree.removeNode(myNode, true);
                tree.save();

                ApacheVirtualHostServiceComponent parentVhost = resourceContext.getParentResourceComponent();

                parentVhost.deleteEmptyFile(tree, myNode);
                parentVhost.conditionalRestart();
            } else {
                log.info("Could find the configuration corresponding to the directory "
                    + resourceContext.getResourceKey() + ". Ignoring.");
            }
        } finally {
            comp.close();
        }
    }

    /**
     * Gets the node from under given node corresponding to the Directory this
     * component is managing.
     * 
     * @param virtualHost
     *            the node of the parent virtualHost (or root node of the augeas
     *            tree)
     * @return
     */
    public AugeasNode getNode(AugeasNode virtualHost) {
        AugeasNode directory = AugeasNodeSearch.findNodeById(virtualHost, resourceContext.getResourceKey());

        return directory;
    }

    public AugeasNode getNode(AugeasTree tree) {
        ApacheVirtualHostServiceComponent virtHost = resourceContext.getParentResourceComponent();
        AugeasNode virtHostNode = resourceContext.getParentResourceComponent().getNode(tree);
        return getNode(virtHostNode);
    }

    public AugeasComponent getAugeas() {
        return resourceContext.getParentResourceComponent().getAugeas();
    }

    /**
     * @see ApacheServerComponent#finishConfigurationUpdate(ConfigurationUpdateReport)
     */
    public void finishConfigurationUpdate(ConfigurationUpdateReport report) {
        resourceContext.getParentResourceComponent().finishConfigurationUpdate(report);
    }

    public boolean isAugeasEnabled() {
        ApacheVirtualHostServiceComponent parent = resourceContext.getParentResourceComponent();
        return parent.isAugeasEnabled();
    }
}
