/*******************************************************************************
 * Copyright (c) 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.ide.dialogs;

import org.eclipse.core.filesystem.IFileInfo;
import org.eclipse.core.filesystem.IFileStore;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.window.Window;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.dialogs.SelectionDialog;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
import org.eclipse.ui.internal.ide.IIDEHelpContextIds;
import org.eclipse.ui.internal.ide.dialogs.FileFolderSelectionDialog;
import org.eclipse.ui.internal.ide.dialogs.IDEResourceInfoUtils;
import org.eclipse.ui.internal.ide.dialogs.PathVariablesGroup;

/**
 * A selection dialog which shows the path variables defined in the 
 * workspace.
 * The <code>getResult</code> method returns the name(s) of the 
 * selected path variable(s).
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * <p>
 * Example:
 * <pre>
 *  PathVariableSelectionDialog dialog =
 *    new PathVariableSelectionDialog(getShell(), IResource.FOLDER);
 *	dialog.open();
 *	String[] result = (String[]) dialog.getResult();
 * </pre> 	
 * </p>
 * 
 * @since 3.1
 */
public final class PathVariableSelectionDialog extends SelectionDialog {
    private static final int EXTEND_ID = IDialogConstants.CLIENT_ID + 1;

    private PathVariablesGroup pathVariablesGroup;

    private int variableType;

    /**
     * Creates a path variable selection dialog.
     *
     * @param parentShell the parent shell
     * @param variableType the type of variables that are displayed in 
     * 	this dialog. <code>IResource.FILE</code> and/or <code>IResource.FOLDER</code>
     * 	logically ORed together.
     */
    public PathVariableSelectionDialog(Shell parentShell, int variableType) {
        super(parentShell);
        setTitle(IDEWorkbenchMessages.PathVariableSelectionDialog_title);
        this.variableType = variableType;
        pathVariablesGroup = new PathVariablesGroup(false, variableType,
                new Listener() {
                    /* (non-Javadoc)
                     * @see org.eclipse.swt.widgets.Listener#handleEvent(org.eclipse.swt.widgets.Event)
                     */
                    public void handleEvent(Event event) {
                        updateExtendButtonState();
                    }
                });
        setShellStyle(getShellStyle() | SWT.RESIZE);
    }


    /* (non-Javadoc)
     * @see org.eclipse.jface.dialogs.Dialog#buttonPressed(int)
     */
    protected void buttonPressed(int buttonId) {
        if (buttonId == EXTEND_ID) {
            FileFolderSelectionDialog dialog = new FileFolderSelectionDialog(
                    getShell(), false, variableType);
            PathVariablesGroup.PathVariableElement selection = pathVariablesGroup
                    .getSelection()[0];
            dialog.setTitle(IDEWorkbenchMessages.PathVariableSelectionDialog_ExtensionDialog_title);
            dialog.setMessage(NLS.bind(IDEWorkbenchMessages.PathVariableSelectionDialog_ExtensionDialog_description, selection.name));
            dialog.setInput(selection.path.toFile());
            if (dialog.open() == Window.OK
                    && pathVariablesGroup.performOk()) {
                setExtensionResult(selection, (IFileStore) dialog.getResult()[0]);
                super.okPressed();
            }
        } else
            super.buttonPressed(buttonId);
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell)
     */
    protected void configureShell(Shell shell) {
        super.configureShell(shell);
        PlatformUI.getWorkbench().getHelpSystem().setHelp(shell,
                IIDEHelpContextIds.PATH_VARIABLE_SELECTION_DIALOG);
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.dialogs.Dialog#createButtonsForButtonBar(org.eclipse.swt.widgets.Composite)
     */
    protected void createButtonsForButtonBar(Composite parent) {
        createButton(parent, IDialogConstants.OK_ID, IDialogConstants.OK_LABEL,
                true);
        createButton(parent, EXTEND_ID, IDEWorkbenchMessages.PathVariableSelectionDialog_extendButton, false);
        createButton(parent, IDialogConstants.CANCEL_ID,
                IDialogConstants.CANCEL_LABEL, false);
        updateExtendButtonState();
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.dialogs.Dialog#createDialogArea(org.eclipse.swt.widgets.Composite)
     */
    protected Control createDialogArea(Composite parent) {
        // create composite 
        Composite dialogArea = (Composite) super.createDialogArea(parent);

        pathVariablesGroup.createContents(dialogArea);
        return dialogArea;
    }

    
    /* (non-Javadoc)
     * @see org.eclipse.jface.window.Window#close()
     */
    public boolean close() {
        pathVariablesGroup.dispose();
        return super.close();
    }

  
    /* (non-Javadoc)
     * @see org.eclipse.jface.dialogs.Dialog#okPressed()
     */
    protected void okPressed() {
		//Sets the dialog result to the selected path variable name(s). 
        if (pathVariablesGroup.performOk()) {
            PathVariablesGroup.PathVariableElement[] selection = pathVariablesGroup
                    .getSelection();
            String[] variableNames = new String[selection.length];

            for (int i = 0; i < selection.length; i++)
                variableNames[i] = selection[i].name;
            setSelectionResult(variableNames);
        } else {
            setSelectionResult(null);
        }
        super.okPressed();
    }

    /**
     * Sets the dialog result to the concatenated variable name and extension.
     * 
     * @param variable variable selected in the variables list and extended
     * 	by <code>extensionFile</code>
     * @param extensionFile file selected to extend the variable.
     */
    private void setExtensionResult(
            PathVariablesGroup.PathVariableElement variable, IFileStore extensionFile) {
        IPath extensionPath = new Path(extensionFile.toString());
        int matchCount = extensionPath.matchingFirstSegments(variable.path);
        IPath resultPath = new Path(variable.name);

        extensionPath = extensionPath.removeFirstSegments(matchCount);
        resultPath = resultPath.append(extensionPath);
        setSelectionResult(new String[] { resultPath.toOSString() });
    }

    /**
     * Updates the enabled state of the Extend button based on the 
     * current variable selection.
     */
    private void updateExtendButtonState() {
        PathVariablesGroup.PathVariableElement[] selection = pathVariablesGroup
                .getSelection();
        Button extendButton = getButton(EXTEND_ID);

        if (extendButton == null)
            return;
        if (selection.length == 1) {
            IFileInfo info = IDEResourceInfoUtils.getFileInfo(selection[0].path);
            if (info.exists() && info.isDirectory())
            	extendButton.setEnabled(true);
            else
                extendButton.setEnabled(false);
                
        } else
            extendButton.setEnabled(false);
    }

}