/**
 * Copyright 2010 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.
 */

package org.guvnor.tools.wizards;

import org.eclipse.core.runtime.IStatus;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
import org.guvnor.tools.Activator;
import org.guvnor.tools.GuvnorRepository;
import org.guvnor.tools.Messages;
import org.guvnor.tools.utils.PlatformUtils;
import org.guvnor.tools.views.RepositoryContentProvider;
import org.guvnor.tools.views.RepositoryLabelProvider;
import org.guvnor.tools.views.model.TreeObject;
import org.guvnor.tools.views.model.TreeParent;

/**
 * Wizard page for selecting a target folder in Guvnor.
 * @author jgraham
 */
public class SelectGuvnorFolderPage extends WizardPage {
	
	private TreeViewer viewer;
	private String previousSelection;
	
	public SelectGuvnorFolderPage(String pageName) {
		super(pageName);
	}
	
	public SelectGuvnorFolderPage(String pageName, String title, ImageDescriptor titleImage) {
		super(pageName, title, titleImage);
	}
	
	public void createControl(Composite parent) {
		Composite composite = PlatformUtils.createComposite(parent, 1);
		new Label(composite, SWT.NONE).setText(Messages.getString("select.folder")); //$NON-NLS-1$
		
		viewer = new TreeViewer(composite, SWT.BORDER | SWT.SINGLE | SWT.H_SCROLL | SWT.V_SCROLL);
		viewer.getTree().setLayoutData(new GridData(GridData.FILL_BOTH));
		viewer.setLabelProvider(new RepositoryLabelProvider());
		viewer.addPostSelectionChangedListener(new ISelectionChangedListener() {
			public void selectionChanged(SelectionChangedEvent event) {
				updateModel();	
			}
		});
		viewer.addFilter(new ViewerFilter() {
			@Override
			public boolean select(Viewer viewer, Object parentElement, Object element) {
				// The snapshots directory in Guvnor is read-only for Eclipse tools
				if (element instanceof TreeObject) {
					TreeObject o = (TreeObject)element;
					return o.getFullPath().indexOf("/snapshots/") == -1; //$NON-NLS-1$
				} else {
					return true;
				}
			}
		});
		super.setControl(composite);
	}
	
	private void handleRepositoryCreation() {
		// First we'll see if the repository already exists
		GuvWizardModel model = ((IGuvnorWizard)super.getWizard()).getModel();
		if (model.shouldCreateNewRep()
		   && model.getRepLocation() != null) {
			GuvnorRepository theRep = Activator.getLocationManager().
										findRepository(model.getRepLocation());
			if (theRep != null) {
				// The repository already exists, nothing to do
				return;
			}
			try {
				WizardUtils.createGuvnorRepository(model);
			} catch (Exception e) {
				super.setErrorMessage(e.getMessage());
				Activator.getDefault().writeLog(IStatus.ERROR, e.getMessage(), e);
			}
		}
	}
	
	@Override
	public void setVisible(boolean visible) {
		if (visible) {
			// Need to filter repository list based on currently selected repository
			// Will also keep track of which filter is applied, so we don't create
			// additional content providers unnecessarily.
			GuvWizardModel model = ((IGuvnorWizard)super.getWizard()).getModel();
			String currentSelection = model.getRepLocation();
			// Not supposed to use this page without setting the target repository in the model
			assert(currentSelection != null);
			// If we had a repository selection before that is different from the current selection
			if (previousSelection != null
			   && !currentSelection.equals(previousSelection)) {
				handleRepositoryCreation();
				RepositoryContentProvider cp = new RepositoryContentProvider();
				cp.setRepositorySelection(currentSelection);
				viewer.setContentProvider(cp);
				viewer.setInput(viewer);
				previousSelection = currentSelection;
			} else {
				// If we didn't have a repository selection before (first time this page is loaded)
				if (previousSelection == null) {
					handleRepositoryCreation();
					RepositoryContentProvider cp = new RepositoryContentProvider();
					cp.setRepositorySelection(currentSelection);
					viewer.setContentProvider(cp);
					viewer.setInput(viewer);
					previousSelection = currentSelection;
				}
			}
		}
		super.setVisible(visible);
	}
	
	private void updateModel() {
		if (super.getErrorMessage() != null) {
			super.setErrorMessage(null);
		}
		IStructuredSelection selection = (IStructuredSelection)viewer.getSelection();
		GuvWizardModel model = ((IGuvnorWizard)super.getWizard()).getModel();
		if (selection.getFirstElement() instanceof TreeParent) {
			TreeParent node = (TreeParent)selection.getFirstElement();
			if (node.getNodeType() == TreeObject.Type.PACKAGE
			   || node.getNodeType() == TreeObject.Type.REPOSITORY) {
				viewer.expandToLevel(node, 1);
				String base = node.getFullPath().endsWith("/")?node.getFullPath():node.getFullPath() + "/"; //$NON-NLS-1$ //$NON-NLS-2$
				model.setTargetLocation(base);
				super.getWizard().getContainer().updateButtons();
			} else {
				model.setTargetLocation(null);
				super.getWizard().getContainer().updateButtons();
			}
		} else {
			model.setTargetLocation(null);
			super.getWizard().getContainer().updateButtons();
		}
	}
}
