/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.dialogs;

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.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
import org.eclipse.ui.internal.ide.IDEWorkbenchPlugin;
import org.eclipse.ui.internal.ide.IIDEHelpContextIds;
import org.eclipse.ui.internal.ide.dialogs.ProjectContentsLocationArea;
import org.eclipse.ui.internal.ide.dialogs.ProjectContentsLocationArea.IErrorMessageReporter;

/**
 * Standard main page for a wizard that is creates a project resource.
 * <p>
 * This page may be used by clients as-is; it may be also be subclassed to suit.
 * </p>
 * <p>
 * Example usage:
 * <pre>
 * mainPage = new WizardNewProjectCreationPage("basicNewProjectPage");
 * mainPage.setTitle("Project");
 * mainPage.setDescription("Create a new project resource.");
 * </pre>
 * </p>
 */
public class WizardNewProjectCreationPage extends WizardPage {

       // initial value stores
    private String initialProjectFieldValue;

    // widgets
    Text projectNameField;

    private Listener nameModifyListener = new Listener() {
        public void handleEvent(Event e) {
        	setLocationForSelection();
            boolean valid = validatePage();
            setPageComplete(valid);
                
        }
    };

	private ProjectContentsLocationArea locationArea;

    // constants
    private static final int SIZING_TEXT_FIELD_WIDTH = 250;

    /**
     * Creates a new project creation wizard page.
     *
     * @param pageName the name of this page
     */
    public WizardNewProjectCreationPage(String pageName) {
        super(pageName);
        setPageComplete(false);
    }

    /** (non-Javadoc)
     * Method declared on IDialogPage.
     */
    public void createControl(Composite parent) {
        Composite composite = new Composite(parent, SWT.NULL);
        composite.setFont(parent.getFont());

        initializeDialogUnits(parent);

        PlatformUI.getWorkbench().getHelpSystem().setHelp(composite,
                IIDEHelpContextIds.NEW_PROJECT_WIZARD_PAGE);

        composite.setLayout(new GridLayout());
        composite.setLayoutData(new GridData(GridData.FILL_BOTH));

        createProjectNameGroup(composite);
        locationArea = new ProjectContentsLocationArea(getErrorReporter(), composite);
        if(initialProjectFieldValue != null)
        	locationArea.updateProjectName(initialProjectFieldValue);

		// Scale the button based on the rest of the dialog
		setButtonLayoutData(locationArea.getBrowseButton());
		
        setPageComplete(validatePage());
        // Show description on opening
        setErrorMessage(null);
        setMessage(null);
        setControl(composite);
    }
    
    /**
	 * Get an error reporter for the receiver.
	 * @return IErrorMessageReporter
	 */
	private IErrorMessageReporter getErrorReporter() {
		return new IErrorMessageReporter(){
			/* (non-Javadoc)
			 * @see org.eclipse.ui.internal.ide.dialogs.ProjectContentsLocationArea.IErrorMessageReporter#reportError(java.lang.String)
			 */
			public void reportError(String errorMessage) {
				setErrorMessage(errorMessage);
				boolean valid = errorMessage == null;
				if(valid)
					valid = validatePage();
				
				setPageComplete(valid);
			}
		};
	}

    /**
     * Creates the project name specification controls.
     *
     * @param parent the parent composite
     */
    private final void createProjectNameGroup(Composite parent) {
        // project specification group
        Composite projectGroup = new Composite(parent, SWT.NONE);
        GridLayout layout = new GridLayout();
        layout.numColumns = 2;
        projectGroup.setLayout(layout);
        projectGroup.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

        // new project label
        Label projectLabel = new Label(projectGroup, SWT.NONE);
        projectLabel.setText(IDEWorkbenchMessages.WizardNewProjectCreationPage_nameLabel);
        projectLabel.setFont(parent.getFont());

        // new project name entry field
        projectNameField = new Text(projectGroup, SWT.BORDER);
        GridData data = new GridData(GridData.FILL_HORIZONTAL);
        data.widthHint = SIZING_TEXT_FIELD_WIDTH;
        projectNameField.setLayoutData(data);
        projectNameField.setFont(parent.getFont());

        // Set the initial value first before listener
        // to avoid handling an event during the creation.
        if (initialProjectFieldValue != null)
            projectNameField.setText(initialProjectFieldValue);
        projectNameField.addListener(SWT.Modify, nameModifyListener);
    }


    /**
     * Returns the current project location path as entered by 
     * the user, or its anticipated initial value.
     * Note that if the default has been returned the path
     * in a project description used to create a project
     * should not be set.
     *
     * @return the project location path or its anticipated initial value.
     */
    public IPath getLocationPath() {
        return new Path(locationArea.getProjectLocation());
    }

    /**
     * Creates a project resource handle for the current project name field value.
     * <p>
     * This method does not create the project resource; this is the responsibility
     * of <code>IProject::create</code> invoked by the new project resource wizard.
     * </p>
     *
     * @return the new project resource handle
     */
    public IProject getProjectHandle() {
        return ResourcesPlugin.getWorkspace().getRoot().getProject(
                getProjectName());
    }

    /**
     * Returns the current project name as entered by the user, or its anticipated
     * initial value.
     *
     * @return the project name, its anticipated initial value, or <code>null</code>
     *   if no project name is known
     */
    public String getProjectName() {
        if (projectNameField == null)
            return initialProjectFieldValue;

        return getProjectNameFieldValue();
    }

    /**
     * Returns the value of the project name field
     * with leading and trailing spaces removed.
     * 
     * @return the project name in the field
     */
    private String getProjectNameFieldValue() {
        if (projectNameField == null)
            return ""; //$NON-NLS-1$

        return projectNameField.getText().trim();
    }

    /**
     * Sets the initial project name that this page will use when
     * created. The name is ignored if the createControl(Composite)
     * method has already been called. Leading and trailing spaces
     * in the name are ignored.
     * Providing the name of an existing project will not necessarily 
     * cause the wizard to warn the user.  Callers of this method 
     * should first check if the project name passed already exists 
     * in the workspace.
     * 
     * @param name initial project name for this page
     * 
     * @see IWorkspace#validateName(String, int)
     * 
     */
    public void setInitialProjectName(String name) {
        if (name == null)
            initialProjectFieldValue = null;
        else {
            initialProjectFieldValue = name.trim();
            if(locationArea != null)
            	locationArea.updateProjectName(name.trim());
        }
    }

    /**
     * Set the location to the default location if we are set to useDefaults.
     */
    void setLocationForSelection() {
    	locationArea.updateProjectName(getProjectNameFieldValue());
    }

  
    /**
     * Returns whether this page's controls currently all contain valid 
     * values.
     *
     * @return <code>true</code> if all controls are valid, and
     *   <code>false</code> if at least one is invalid
     */
    protected boolean validatePage() {
        IWorkspace workspace = IDEWorkbenchPlugin.getPluginWorkspace();

        String projectFieldContents = getProjectNameFieldValue();
        if (projectFieldContents.equals("")) { //$NON-NLS-1$
            setErrorMessage(null);
            setMessage(IDEWorkbenchMessages.WizardNewProjectCreationPage_projectNameEmpty);
            return false;
        }

        IStatus nameStatus = workspace.validateName(projectFieldContents,
                IResource.PROJECT);
        if (!nameStatus.isOK()) {
            setErrorMessage(nameStatus.getMessage());
            return false;
        }

        String locationValidation = locationArea.checkValidLocation();
        if(locationValidation != null){
        	setErrorMessage(locationValidation);
            return false;
        }

        IProject handle = getProjectHandle();
        if (handle.exists()) {
            setErrorMessage(IDEWorkbenchMessages.WizardNewProjectCreationPage_projectExistsMessage);
            return false;
        }
        
        /*
         * If not using the default value validate the location.
         */
        if (!locationArea.isDefault()) {
            IStatus locationStatus = workspace.validateProjectLocation(handle,
                    new Path(locationArea.getProjectLocation()));
            if (!locationStatus.isOK()) {
                setErrorMessage(locationStatus.getMessage());
                return false;
            }
        }

        setErrorMessage(null);
        setMessage(null);
        return true;
    }

    /*
     * see @DialogPage.setVisible(boolean)
     */
    public void setVisible(boolean visible) {
        super.setVisible(visible);
        if (visible)
            projectNameField.setFocus();
    }

    /**
     * Returns the useDefaults.
     * @return boolean
     */
    public boolean useDefaults() {
        return locationArea.isDefault();
    }

}