package org.drools.eclipse.flow.ruleflow.editor;
/*
 * Copyright 2005 JBoss Inc
 * 
 * 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.
 */

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.StringReader;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.drools.compiler.PackageBuilderConfiguration;
import org.drools.eclipse.DroolsEclipsePlugin;
import org.drools.eclipse.WorkItemDefinitions;
import org.drools.eclipse.flow.common.editor.GenericModelEditor;
import org.drools.eclipse.flow.ruleflow.core.RuleFlowProcessWrapper;
import org.drools.eclipse.flow.ruleflow.core.RuleFlowWrapperBuilder;
import org.drools.eclipse.flow.ruleflow.core.StartNodeWrapper;
import org.drools.eclipse.flow.ruleflow.core.WorkItemWrapper;
import org.drools.eclipse.flow.ruleflow.editor.editpart.RuleFlowEditPartFactory;
import org.drools.eclipse.util.ProjectClassLoader;
import org.drools.process.core.WorkDefinition;
import org.drools.process.core.WorkDefinitionExtension;
import org.drools.ruleflow.core.RuleFlowProcess;
import org.drools.xml.XmlProcessReader;
import org.drools.xml.XmlRuleFlowProcessDumper;
import org.drools.xml.processes.RuleFlowMigrator;
import org.eclipse.core.resources.IFile;
import org.eclipse.draw2d.geometry.Rectangle;
import org.eclipse.gef.EditPartFactory;
import org.eclipse.gef.palette.CombinedTemplateCreationEntry;
import org.eclipse.gef.palette.PaletteDrawer;
import org.eclipse.gef.palette.PaletteRoot;
import org.eclipse.gef.requests.SimpleFactory;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IFileEditorInput;

/**
 * Graphical editor for a RuleFlow.
 * 
 * @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>
 */
public class RuleFlowModelEditor extends GenericModelEditor {

    protected EditPartFactory createEditPartFactory() {
    	RuleFlowEditPartFactory factory = new RuleFlowEditPartFactory();
    	factory.setProject(getJavaProject());
        return factory;
    }

    protected PaletteRoot createPalette() {
        return RuleFlowPaletteFactory.createPalette();
    }

    protected Object createModel() {
        RuleFlowProcessWrapper result = new RuleFlowProcessWrapper();
        StartNodeWrapper start = new StartNodeWrapper();
        start.setConstraint(new Rectangle(100, 100, -1, -1));
        result.addElement(start);
        start.setParent(result);
        IFile file = ((IFileEditorInput)getEditorInput()).getFile();
        String name = file.getName();
        result.setName(name.substring(0, name.length() - 3));
        return result;
    }
    
    public RuleFlowProcessWrapper getRuleFlowModel() {
        return (RuleFlowProcessWrapper) getModel();
    }

    protected void setInput(IEditorInput input) {
        super.setInput(input);
        if (input instanceof IFileEditorInput) {
        	refreshPalette(((IFileEditorInput) input).getFile());
        }
    }
    
    private void refreshPalette(IFile file) {
        IJavaProject javaProject = getJavaProject();
        if (javaProject != null) {
            try {
                ClassLoader oldLoader = Thread.currentThread().getContextClassLoader();
                ClassLoader newLoader = ProjectClassLoader.getProjectClassLoader(javaProject);
                try {
                    Thread.currentThread().setContextClassLoader(newLoader);
                    PaletteDrawer drawer = (PaletteDrawer) getPaletteRoot().getChildren().get(2);
                    List entries = new ArrayList();
                    try {
	                    for (final WorkDefinition workDefinition: WorkItemDefinitions.getWorkDefinitions(file).values()) {
	                        final String label;
	                        String description = workDefinition.getName();
	                        String icon = null;
	                        if (workDefinition instanceof WorkDefinitionExtension) {
	                            WorkDefinitionExtension extension = (WorkDefinitionExtension) workDefinition;
	                            label = extension.getDisplayName();
	                            description = extension.getExplanationText();
	                            icon = extension.getIcon();
	                        } else {
	                            label = workDefinition.getName();
	                        }
	                        
	                        URL iconUrl = null;
	                        if (icon != null) {
	                            iconUrl = newLoader.getResource(icon);
	                        }
	                        if (iconUrl == null) {
	                            iconUrl = DroolsEclipsePlugin.getDefault().getBundle().getEntry("icons/action.gif");
	                        }
	                        CombinedTemplateCreationEntry combined = new CombinedTemplateCreationEntry(
	                            label,
	                            description,
	                            WorkItemWrapper.class,
	                            new SimpleFactory(WorkItemWrapper.class) {
	                                public Object getNewObject() {
	                                    WorkItemWrapper workItemWrapper = (WorkItemWrapper) super.getNewObject();
	                                    workItemWrapper.setName(label);
	                                    workItemWrapper.setWorkDefinition(workDefinition);
	                                    return workItemWrapper;
	                                }
	                            },
	                            ImageDescriptor.createFromURL(iconUrl), 
	                            ImageDescriptor.createFromURL(iconUrl)
	                        );
	                        entries.add(combined);
	                    }
                    } catch (Throwable t) {
                		MessageDialog.openError(
                			getSite().getShell(), "Parsing work item definitions", t.getMessage());
                    }
                    drawer.setChildren(entries);
                } finally {
                    Thread.currentThread().setContextClassLoader(oldLoader);
                }
            } catch (Exception e) {
                DroolsEclipsePlugin.log(e);
            }
        }
    }

    protected void writeModel(OutputStream os) throws IOException {
    	writeModel(os, true);
    }
    
    protected void writeModel(OutputStream os, boolean includeGraphics) throws IOException {
        OutputStreamWriter writer = new OutputStreamWriter(os);
        try {
            XmlRuleFlowProcessDumper dumper = XmlRuleFlowProcessDumper.INSTANCE;
            String out = dumper.dump(getRuleFlowModel().getRuleFlowProcess(), includeGraphics);
            writer.write(out);
        } catch (Throwable t) {
            DroolsEclipsePlugin.log(t);
        }
        writer.close();
    }
    
    
    protected void createModel(InputStream is) {
    	try 
    	{
    		InputStreamReader isr = new InputStreamReader(is);
    		PackageBuilderConfiguration configuration = new PackageBuilderConfiguration();
    		XmlProcessReader xmlReader = new XmlProcessReader( configuration.getSemanticModules() );
    		
    		//Migrate v4 ruleflows to v5
    		Reader reader = null;
    		try 
    		{
    			String xml = RuleFlowMigrator.convertReaderToString(isr);
    			if (RuleFlowMigrator.needToMigrateRFM(xml))
    			{
    				xml = RuleFlowMigrator.portRFToCurrentVersion(xml);
    				MessageDialog.openInformation(this.getSite().getShell(),
    			            "Incompatible RuleFlow Version", 
    			            "WARNING! The selected RuleFlow is Drools version 4 format.\n\n" +
    			            "Any changes made to this RuleFlow will be saved in Drools 5 format, which is " +
    			            "not compatible with Drools 4. To convert this RuleFlow " +
    			            "to Drools 5 format, select Save As from the File menu and overwrite this " +
    			            "file - the new RuleFlow file will be saved in Drools 5 format.");
    			}
    			
    			reader =  new StringReader(xml);

    			RuleFlowProcess process = (RuleFlowProcess) xmlReader.read(reader);
    			if (process == null) {
    				setModel(createModel());
    			} else {
    				setModel(new RuleFlowWrapperBuilder().getProcessWrapper(process, getJavaProject()));
    			}
    		} catch (Throwable t) {
    			DroolsEclipsePlugin.log(t);
    			MessageDialog.openError( getSite().getShell(),
                    "Could not read RuleFlow file",
                    "An exception occurred while reading in the RuleFlow XML: "
                    	+ t.getMessage() + " See the error log for more details.");
    			setModel(createModel());
    		}

    		if (reader != null){
    			reader.close();
    		}
    	} catch (Throwable t) {
    		DroolsEclipsePlugin.log(t);
    	}
    }
}
