/*
 * Copyright (c) 2014, the Dart project authors.
 * 
 * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
 * 
 * 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 com.google.dart.eclipse.wizards;

import com.google.dart.eclipse.DartEclipseUI;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.jface.layout.GridLayoutFactory;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.DirectoryDialog;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;

/**
 * Wizard page for the Import Dart Wizard. Imports existing Dart source as a project.
 */
public class ImportFolderWizardPage extends WizardPage {

  private Label directoryLabel;
  private Button browseButton;
  private Text existingSourcePathText;
  private Text projectNameText;

  protected ImportFolderWizardPage() {
    super("wizard page");
    setImageDescriptor(DartEclipseUI.getImageDescriptor("wizban/importdir_wiz.png"));
    setDescription("Create a Dart project from existing source");
    setTitle("Import Dart Source");
  }

  @Override
  public void createControl(Composite parent) {
    initializeDialogUnits(parent);
    Composite container = new Composite(parent, SWT.NULL);
    GridLayoutFactory.swtDefaults().spacing(5, 1).applyTo(container);
    GridLayout gridLayout = new GridLayout();
    gridLayout.numColumns = 3;
    gridLayout.marginWidth = 10;
    gridLayout.marginHeight = 10;

    container.setLayout(gridLayout);

    Label projectLabel = new Label(container, SWT.NONE);
    projectLabel.setText("Project Name:");
    projectNameText = new Text(container, SWT.BORDER);
    GridDataFactory.swtDefaults().align(SWT.FILL, SWT.CENTER).span(2, 1).grab(true, false).applyTo(
        projectNameText);
    projectNameText.addModifyListener(new ModifyListener() {

      @Override
      public void modifyText(ModifyEvent e) {
        updatePage();
      }
    });

    directoryLabel = new Label(container, SWT.NONE);
    directoryLabel.setText("Directory:");

    existingSourcePathText = new Text(container, SWT.BORDER);
    GridDataFactory.swtDefaults().align(SWT.FILL, SWT.CENTER).grab(true, false).applyTo(
        existingSourcePathText);
    existingSourcePathText.addModifyListener(new ModifyListener() {

      @Override
      public void modifyText(ModifyEvent e) {
        updatePage();
      }
    });

    browseButton = new Button(container, SWT.NONE);
    browseButton.setText("Browse...");
    browseButton.setEnabled(true);
    browseButton.addSelectionListener(new SelectionAdapter() {

      @Override
      public void widgetSelected(SelectionEvent e) {
        String selPath = new DirectoryDialog(getShell()).open();

        if (selPath != null) {
          existingSourcePathText.setText(selPath);
        }
      }
    });
    setPageComplete(false);
    setMessage("Enter a project name");
    setControl(container);
  }

  public String getProjectLocation() {
    return existingSourcePathText.getText().trim();
  }

  public String getProjectName() {
    return projectNameText.getText().trim();
  }

  private void updatePage() {

    final IWorkspace workspace = ResourcesPlugin.getWorkspace();

    final String name = projectNameText.getText().trim();

    // check whether the project name field is empty
    if (name.length() == 0) {
      setErrorMessage(null);
      setMessage("Enter a project name");
      setPageComplete(false);
      return;
    }

    // check whether the project name is valid
    final IStatus nameStatus = workspace.validateName(name, IResource.PROJECT);
    if (!nameStatus.isOK()) {
      setErrorMessage(nameStatus.getMessage());
      setPageComplete(false);
      return;
    }

    // check whether project already exists
    final IProject handle = workspace.getRoot().getProject(name);
    if (handle.exists()) {
      setErrorMessage("A project with this name already exists");
      setPageComplete(false);
      return;
    }

    final String location = existingSourcePathText.getText().trim();

    // check whether location is empty
    if (location.length() == 0) {
      setErrorMessage(null);
      setMessage("Select a directory to import");
      setPageComplete(false);
      return;
    }

    // check whether the location is a syntactically correct path
    if (!Path.EMPTY.isValidPath(location)) {
      setErrorMessage("Invalid project contents directory");
      setPageComplete(false);
      return;
    }

    IPath projectPath = Path.fromOSString(location);

    // validate the location
    final IStatus locationStatus = workspace.validateProjectLocation(handle, projectPath);
    if (!locationStatus.isOK()) {
      setErrorMessage(locationStatus.getMessage());
      setPageComplete(false);
      return;
    }

    setPageComplete(true);

    setErrorMessage(null);
    setMessage("Create a Dart project from existing source");
  }

}