package pyUML.views;


import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IEditorPart;
import org.eclipse.uml2.uml.Model;

import pyUML.actions.ManageViewsAction;
import pyUML.backend.GlobalConstants;
import pyUML.backend.JavaHelperMethods;
import pyUML.backend.UMLToolsHelperMethods;
import pyUML.listeners.ViewChangeListener;


/**
 * This is the dialog for managing pyUML.views.
 * Views can be selected, deleted, edited and created.
 * A listener is implemented with this class, so here
 * is defined what happens when you press buttons in the dialog.
 */
public class ManageViewsPage extends Dialog implements SelectionListener{
	Composite composite = null;
	Group viewsBoxGroup = null;
	List viewsBox = null;
	Button openButton = null;
	Button editButton = null;
	Button deleteButton = null;
	Button createNewButton = null;
	Model model;
	IProject project;
	
	Shell shell=null;
	
	public ManageViewsPage(Shell parent, Model model, IProject project){
		super(parent);
		this.model= model;
		this.project=project;
		
	}

	protected Control createDialogArea(Composite parent) {	
		this.composite = (Composite) super.createDialogArea(parent);
		setShellStyle(SWT.DIALOG_TRIM | SWT.RESIZE | SWT.MAX);	
		createControls(composite);
		initializeDialog();
		//add controls to composite as necessary
		return composite;
		} 
	

	public void createControls	(Composite composite) {
		// create graphical components
		shell = composite.getShell();
		shell.setText("Manage UML Views");
		
		viewsBoxGroup = new Group(composite, SWT.None);
		viewsBoxGroup.setText("Available Views");

		viewsBoxGroup.setLayoutData(new GridData(GridData.FILL_BOTH));
		viewsBoxGroup.setLayout(new GridLayout(1, true));

		
		viewsBox = new List( viewsBoxGroup, SWT.BORDER|SWT.SINGLE|SWT.V_SCROLL|SWT.H_SCROLL	 );
		viewsBox.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
		
		Composite buttonGroup = new Composite(viewsBoxGroup, SWT.NONE);
		buttonGroup.setLayoutData(new GridData(GridData.FILL_BOTH));
		buttonGroup.setLayout(new GridLayout(3, true));
		
		viewsBox.setSize(300,300);
		
		openButton = new Button(buttonGroup, SWT.PUSH);
		openButton.setText("Open View");
		openButton.addSelectionListener(this);
		
		editButton = new Button(buttonGroup, SWT.PUSH);
		editButton.setText("Edit View");
		editButton.addSelectionListener(this);

		deleteButton = new Button(buttonGroup, SWT.PUSH);
		deleteButton.setText("Delete View");
		deleteButton.addSelectionListener(this);

		
		buttonGroup.pack();
		viewsBoxGroup.pack();
		setElementEnabled(false, viewsBoxGroup);
		
		createNewButton = new Button(composite, SWT.PUSH);
		createNewButton.setText("Create New View");
		createNewButton.setLayoutData(new GridData(GridData.FILL_BOTH));
		createNewButton.addSelectionListener(this);
		
		composite.pack();

	}

	
	/**
	 * Sets a composite element and all children enabled/disabled
	 * @param enabled
	 * @param element
	 */
	public static void setElementEnabled(boolean enabled, Control element) {
		element.setEnabled(enabled);
		if (element instanceof Composite) {
			Composite comp = (Composite) element;
			for (Control child : comp.getChildren()) {
				setElementEnabled(enabled, child);
			}
		}
	}
	
	public void widgetDefaultSelected(SelectionEvent e) {
		// Auto-generated method stub	
	}

	/**
	 * Handles pressed-button events and runs appropriate pyUML.actions
	 */
	public void widgetSelected(SelectionEvent e) {
		// "CREATE NEW" BUTTON
		if (e.getSource() == this.createNewButton) {
			this.createDialog();
			
			// re-open View management window
			this.cancelPressed();
		} 
		//DELETE BUTTON 
		else if (e.getSource() == this.deleteButton) {
			
			// return if nothing was selected
			if (this.viewsBox.getSelection().length <= 0)
				return;
			
			// warn before deletion
			if (MessageDialog.openConfirm(null, "Confirm deletion of view", 
					"Do you really want to delete this view?") == false)
				return;
			
			// delete view configuration, UML model and diagram 
			String selectedElement = this.viewsBox.getSelection()[0];
			IPath conFilePath = project.getFullPath().append(GlobalConstants.getPyUmlDir())
					.append(selectedElement+GlobalConstants.getViewConfExtension());
			IFile confFile = this.project.getWorkspace().getRoot().getFile(conFilePath);
			IPath umlFilePath = project.getFullPath().append(GlobalConstants.getPyUmlDir())
					.append(selectedElement+GlobalConstants.getViewUmlExtension());
			IFile umlFile = this.project.getWorkspace().getRoot().getFile(umlFilePath);
			IPath diagramFilePath = project.getFullPath().append(GlobalConstants.getPyUmlDir())
					.append(selectedElement+GlobalConstants.getDiagramExtension());
			IFile diagramFile = this.project.getWorkspace().getRoot().getFile(diagramFilePath);

			try {
				if (confFile.exists())
					confFile.delete(false, null);
				if (umlFile.exists())
					umlFile.delete(false, null);
				if (diagramFile.exists())
					diagramFile.delete(false, null);
			} catch (CoreException err) {
				MessageDialog.openError(null, "Error deleting element", 
						"Could not delete view. Reason:\n"+err.getMessage());
			}
			this.cancelPressed();	
			ManageViewsAction.run(project);
			
		// OPEN BUTTON
		} else if (e.getSource() == this.openButton) {
			if (this.viewsBox.getSelection().length <= 0)
				return;
			String ViewUmlFileName = this.viewsBox.getSelection()[0]+GlobalConstants.getViewUmlExtension();
			String ViewConfFileName = this.viewsBox.getSelection()[0]+GlobalConstants.getViewConfExtension();
			String selectedElement = this.viewsBox.getSelection()[0]+GlobalConstants.getDiagramExtension();
			IFile viewDiagramFile = this.project.getWorkspace().getRoot().
				getFile(project.getFullPath().append(GlobalConstants.getPyUmlDir()).
					append(selectedElement));
			IFile viewConfFile = this.project.getWorkspace().getRoot().
			getFile(project.getFullPath().append(GlobalConstants.getPyUmlDir()).
				append(ViewConfFileName));

			if (! viewDiagramFile.exists()) {
				MessageDialog.openError(null, "Error opening view", "The selected view could not be opened;\n" +
						"The UML diagram does not seem to exist!");
			} else {
				UMLToolsHelperMethods.updateViewModel(project, viewConfFile);
				IEditorPart newPage = null;
				try {
				newPage = UMLToolsHelperMethods.refreshDiagramEditor(this.project, viewDiagramFile, false);
				} catch (Throwable t) {
					t.printStackTrace();
				}
				if (newPage == null)
					newPage = UMLToolsHelperMethods.openDiagram(this.project, viewDiagramFile, ViewUmlFileName, true);
				
				
				if ( newPage == null) {
					MessageDialog.openError(null, "Error opening view", "The selected view could not be opened!");
				}
				else {
					newPage.addPropertyListener(new ViewChangeListener(this.project));
					this.close();
				}
			}
		} // EDIT BUTTON 
		else if (e.getSource() == this.editButton) {
			
			String selectedViewName = this.viewsBox.getSelection()[0];
			
			IFile confFile = this.project.getWorkspace().getRoot().getFile(project.getFullPath().append(GlobalConstants.getPyUmlDir()).append(selectedViewName + GlobalConstants.getViewConfExtension()));
			IFile viewDiagramFile = this.project.getWorkspace().getRoot().getFile(project.getFullPath().append(GlobalConstants.getPyUmlDir()).append(selectedViewName + GlobalConstants.getDiagramExtension()));
			
			
			// open view editor
			new EditView(this.project, confFile, selectedViewName, true);
			
			// reload View, if it is already opened 
			UMLToolsHelperMethods.refreshDiagramEditor(project, viewDiagramFile, true);
			
			// re-open View management window
			this.cancelPressed();	
			ManageViewsAction.run(project);
		}
	}
	
	/**
	 * creates a "new View" dialog
	 * creates an empty view config file and runs "edit" on this file
	 */
	public void createDialog() {
		String viewName = "newView";
		String newViewName = viewName;
		IPath filePath=this.project.getLocation().append(GlobalConstants.getPyUmlDir());
		
		// find initial filename that is not already used
		int i=0;
		java.io.File f;
		do {
			newViewName = viewName+(i==0?"":i);
			String fileName=filePath.append(newViewName +GlobalConstants.getViewConfExtension()).toOSString();
			f= new java.io.File(fileName);
			i++;
		} while (f.exists());
		
		// create initial config file
		try{
			IFile confFile = this.project.getWorkspace().getRoot().getFile(project.getFullPath().append(GlobalConstants.getPyUmlDir()).append(newViewName + GlobalConstants.getViewConfExtension()));
			confFile.create(JavaHelperMethods.stringToStream(""), false, null);
			
			//open "edit view" editor
			new EditView(this.project, confFile, newViewName, true);
			this.close();
			
		} catch (CoreException err) {
			MessageDialog.openError(null, "Cannot create View", "View could not be created.\n" +
					"Reason:\n"+err.getMessage());
			return;
		}
		

	}
	
	/**
	 * re-reads available pyUML.views from hard disk
	 */
	protected void initializeDialog() {
		boolean viewFound = false;
		String pyUmlDir = project.getLocation().append(GlobalConstants.getPyUmlDir()).toOSString();
		java.io.File umlDir = new java.io.File(pyUmlDir);
		if (umlDir.list() == null) {
			MessageDialog.openError(null, "Error Managing Views", 
					"No UML Model was found.\n" +
					"Please create a Model before creating a View!");
			this.close();
			return;
		}

		for (String file : umlDir.list()) {
			if (file.matches(".*.pyUmlView.uml$")) {
				viewFound=true;
				this.viewsBox.add(file.replace(".pyUmlView.uml", ""));
				this.viewsBox.add("a");
				this.viewsBox.remove(this.viewsBox.getItemCount()-1);
			}
		}
		
		if (viewFound)
			setElementEnabled(true, viewsBoxGroup);
		else
			setElementEnabled(false, viewsBoxGroup);
	}
}