/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2011, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.as.domain.controller.operations.coordination;

import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.DOMAIN_UUID;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.EXECUTE_FOR_COORDINATOR;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.HOST;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.OP;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.OPERATION_HEADERS;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.OP_ADDR;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.RUNNING_SERVER;
import static org.jboss.as.domain.controller.DomainControllerLogger.HOST_CONTROLLER_LOGGER;

import java.util.Map;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.ExecutorService;

import org.jboss.as.controller.ControllerMessages;
import org.jboss.as.controller.OperationContext;
import org.jboss.as.controller.OperationFailedException;
import org.jboss.as.controller.OperationStepHandler;
import org.jboss.as.controller.PathAddress;
import org.jboss.as.controller.PathElement;
import org.jboss.as.controller.ProxyController;
import org.jboss.as.controller.extension.ExtensionRegistry;
import org.jboss.as.controller.registry.ImmutableManagementResourceRegistration;
import org.jboss.as.controller.registry.OperationEntry;
import org.jboss.as.domain.controller.LocalHostControllerInfo;
import org.jboss.as.domain.controller.operations.ApplyMissingDomainModelResourcesHandler;
import org.jboss.as.host.controller.ignored.IgnoredDomainResourceRegistry;
import org.jboss.as.host.controller.mgmt.DomainControllerRuntimeIgnoreTransformationRegistry;
import org.jboss.as.repository.ContentRepository;
import org.jboss.dmr.ModelNode;

/**
 * Initial step handler for a {@link org.jboss.as.controller.ModelController} that is the model controller for a host controller.
 *
 * @author Brian Stansberry (c) 2011 Red Hat Inc.
 */
public class PrepareStepHandler  implements OperationStepHandler {

    private final LocalHostControllerInfo localHostControllerInfo;
    private final OperationCoordinatorStepHandler coordinatorHandler;
    private final OperationSlaveStepHandler slaveHandler;

    public PrepareStepHandler(final LocalHostControllerInfo localHostControllerInfo,
                              final ContentRepository contentRepository,
                              final Map<String, ProxyController> hostProxies,
                              final Map<String, ProxyController> serverProxies,
                              final IgnoredDomainResourceRegistry ignoredDomainResourceRegistry,
                              final ExtensionRegistry extensionRegistry,
                              final DomainControllerRuntimeIgnoreTransformationRegistry runtimeIgnoreTransformationRegistry) {
        this.localHostControllerInfo = localHostControllerInfo;
        this.slaveHandler = new OperationSlaveStepHandler(localHostControllerInfo, serverProxies, ignoredDomainResourceRegistry, extensionRegistry);
        this.coordinatorHandler = new OperationCoordinatorStepHandler(localHostControllerInfo, contentRepository, hostProxies, serverProxies, slaveHandler, runtimeIgnoreTransformationRegistry);
    }

    public void initialize(ApplyMissingDomainModelResourcesHandler applyMissingDomainModelResourcesHandler) {
        slaveHandler.intialize(applyMissingDomainModelResourcesHandler);
    }

    @Override
    public void execute(OperationContext context, ModelNode operation) throws OperationFailedException {

        if (context.isBooting()) {
            executeDirect(context, operation);
        } else if (operation.hasDefined(OPERATION_HEADERS)
                && operation.get(OPERATION_HEADERS).hasDefined(EXECUTE_FOR_COORDINATOR)
                && operation.get(OPERATION_HEADERS).get(EXECUTE_FOR_COORDINATOR).asBoolean()) {
            // Coordinator wants us to execute locally and send result including the steps needed for execution on the servers
            // TODO verify this is actually the master requesting this
            slaveHandler.execute(context, operation);
        } else {
            // Assign a unique id to this operation to allow tying together of audit logs from various hosts/servers
            // impacted by it

            if (!operation.hasDefined(OPERATION_HEADERS) || !operation.get(OPERATION_HEADERS).hasDefined(DOMAIN_UUID)) {
                operation.get(OPERATION_HEADERS, DOMAIN_UUID).set(UUID.randomUUID().toString());
            }

            if (isServerOperation(operation)) {
                // Pass direct requests for the server through whether they come from the master or not
                executeDirect(context, operation);
            } else {
                coordinatorHandler.execute(context, operation);
            }
        }
    }

    public void setExecutorService(final ExecutorService executorService) {
        coordinatorHandler.setExecutorService(executorService);
    }

    private boolean isServerOperation(ModelNode operation) {
        PathAddress addr = PathAddress.pathAddress(operation.get(OP_ADDR));
        return addr.size() > 1
                && HOST.equals(addr.getElement(0).getKey())
                && localHostControllerInfo.getLocalHostName().equals(addr.getElement(0).getValue())
                && RUNNING_SERVER.equals(addr.getElement(1).getKey());
    }

    /**
     * Directly handles the op in the standard way the default prepare step handler would
     * @param context the operation execution context
     * @param operation the operation
     * @throws OperationFailedException if there is no handler registered for the operation
     */
    private void executeDirect(OperationContext context, ModelNode operation) throws OperationFailedException {
        if (HOST_CONTROLLER_LOGGER.isTraceEnabled()) {
            HOST_CONTROLLER_LOGGER.tracef("%s executing direct", getClass().getSimpleName());
        }
        executeDirectOperation(context, operation);
    }

    static void executeDirectOperation(OperationContext context, ModelNode operation) throws OperationFailedException {
        final String operationName =  operation.require(OP).asString();
        OperationStepHandler stepHandler;
        final ImmutableManagementResourceRegistration registration = context.getResourceRegistration();
        if (registration != null) {
            stepHandler = registration.getOperationHandler(PathAddress.EMPTY_ADDRESS, operationName);
        } else {
            stepHandler = resolveWildcardOperationHandler(PathAddress.pathAddress(operation.get(OP_ADDR)), operationName,
                    context.getRootResourceRegistration());
        }
        if (stepHandler != null) {
            context.addStep(stepHandler, OperationContext.Stage.MODEL);
        } else {
            PathAddress pathAddress = PathAddress.pathAddress(operation.get(OP_ADDR));
            if (registration == null) {
                context.getFailureDescription().set(ControllerMessages.MESSAGES.noSuchResourceType(pathAddress));
            } else {
                context.getFailureDescription().set(ControllerMessages.MESSAGES.noHandlerForOperation(operationName, pathAddress));
            }
        }
        context.stepCompleted();
    }

    private static OperationStepHandler resolveWildcardOperationHandler(final PathAddress address, final String operationName,
                                                                 final ImmutableManagementResourceRegistration rootRegistration) {
        OperationStepHandler result = null;
        if (address.size() > 0) {
            // For wildcard elements, check specific registrations where the same OSH is used
            // for all such registrations
            PathElement pe = address.getLastElement();
            if (pe.isWildcard()) {
                String type = pe.getKey();
                PathAddress parent = address.subAddress(0, address.size() - 1);
                Set<PathElement> children = rootRegistration.getChildAddresses(parent);
                if (children != null) {
                    OperationStepHandler found = null;
                    for (PathElement child : children) {
                        if (type.equals(child.getKey())) {
                            OperationEntry oe = rootRegistration.getOperationEntry(parent.append(child), operationName);
                            OperationStepHandler osh = oe == null ? null : oe.getOperationHandler();
                            if (osh == null || (found != null && !found.equals(osh))) {
                                // Not all children have the same handler; give up
                                found = null;
                                break;
                            }
                            // We have a candidate OSH
                            found = osh;
                        }
                    }
                    if (found != null) {
                        result = found;
                    }
                }
            }
        }
        return result;
    }

}
