/*******************************************************************************
 * Copyright (c) 2010 SAP AG.
 * 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:
 *    Emil Simeonov - initial API and implementation.
 *    Dimitar Donchev - initial API and implementation.
 *    Dimitar Tenev - initial API and implementation.
 *    Nevena Manova - initial API and implementation.
 *    Georgi Konstantinov - initial API and implementation.
 *    Stanislav Nichev - initial API and implementation.
 *******************************************************************************/
package org.eclipse.wst.sse.sieditor.model.reconcile;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.commands.ExecutionException;
import org.eclipse.emf.transaction.Transaction;
import org.eclipse.wst.xml.core.internal.document.XMLModelNotifier;
import org.eclipse.xsd.XSDSchema;

import org.eclipse.wst.sse.sieditor.command.common.AbstractNotificationOperation;
import org.eclipse.wst.sse.sieditor.core.common.IModelReconcileRegistry;
import org.eclipse.wst.sse.sieditor.model.XMLModelNotifierWrapper;
import org.eclipse.wst.sse.sieditor.model.api.IModelObject;
import org.eclipse.wst.sse.sieditor.model.api.IModelRoot;
import org.eclipse.wst.sse.sieditor.model.api.IWsdlModelRoot;
import org.eclipse.wst.sse.sieditor.model.api.IXSDModelRoot;
import org.eclipse.wst.sse.sieditor.model.reconcile.commands.WSDLModelReconcileCommand;
import org.eclipse.wst.sse.sieditor.model.reconcile.commands.XMLSchemaModelReconcileCommand;
import org.eclipse.wst.sse.sieditor.model.wsdl.api.IDescription;

/**
 * This is default implementation of the {@link IModelReconciler} interface.
 * 
 */
public class ModelReconciler implements IModelReconciler {

    private static final IModelReconciler INSTANCE = new ModelReconciler();

    private ModelReconciler() {

    }

    public static IModelReconciler instance() {
        return INSTANCE;
    }

    @Override
    public void aboutToReconcileModel(final IModelReconcileRegistry modelReconcileRegistry) {
        modelReconcileRegistry.clearRegistry();
    }

    @Override
    public boolean needsToReconcileModel(final IModelReconcileRegistry modelReconcileRegistry) {
        // This is a patch overriding an optimisation in the model reconciler
        // execution. It strives to reduce the amount of unnecessary model
        // reconciler executions.
        // The modelReconcileRegistry is designed to indicate if the model
        // reconciler needs to be run. In order to do so, flags in it should be
        // raised in certain cases. Unfortunately not all cases have been
        // handled, thus the optimisation is not always functionally correct.
        // *****
        // Therefore with this patch the reconciler will always be called. If
        // there
        // is a performance issue, commented code should be placed(applying the
        // optimisation), and the unhandled cases - handled.

        return true/* modelReconcileRegistry.needsReconciling() */;
    }

    @Override
    public void reconcileModel(final IModelRoot modelRoot, final IModelReconcileRegistry modelReconcileRegistry) {
        final IModelObject modelObject = modelRoot.getModelObject();

        if (modelRoot instanceof IWsdlModelRoot) {
            final IDescription description = ((IWsdlModelRoot) modelRoot).getDescription();
            reconcileWsdlModel(description, modelRoot, modelObject);

        } else if (modelRoot instanceof IXSDModelRoot) {
            reconcileXsdModel(((IXSDModelRoot) modelRoot).getSchema().getComponent(), modelRoot, modelObject);
        }
    }

    @Override
    public void modelReconciled(final IModelReconcileRegistry modelReconcileRegistry, final XMLModelNotifier xmlModelNotifier) {
        modelReconcileRegistry.clearRegistry();
        if (xmlModelNotifier instanceof XMLModelNotifierWrapper) {
            ((XMLModelNotifierWrapper) xmlModelNotifier).getChangedNodes().clear();
        }
    }

    private void reconcileWsdlModel(final IDescription description, final IModelRoot modelRoot, final IModelObject modelObject) {
        final WSDLModelReconcileCommand command = new WSDLModelReconcileCommand(modelRoot, modelObject, description);
        executeReconcileModelCommand(command);
    }

    private void reconcileXsdModel(final XSDSchema schema, final IModelRoot modelRoot, final IModelObject modelObject) {
        final XMLSchemaModelReconcileCommand command = new XMLSchemaModelReconcileCommand(modelRoot, modelObject, schema);
        executeReconcileModelCommand(command);
    }

    private void executeReconcileModelCommand(final AbstractNotificationOperation command) {
        try {
            final Map<Object, Object> options = new HashMap<Object, Object>();
            options.put(Transaction.OPTION_NO_VALIDATION, Boolean.TRUE);
            options.put(Transaction.OPTION_NO_UNDO, Boolean.TRUE);

            command.setOptions(options);
            command.setReuseParentTransaction(true);

            command.execute(null, null);

        } catch (final ExecutionException e) {
            throw new RuntimeException(e);
        }
    }
}