/*******************************************************************************
 * Copyright (c) 2000, 2009 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.actions;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourceAttributes;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.jface.dialogs.ErrorDialog;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;

import com.ibm.icu.text.MessageFormat;

/**
 * The ReadOnlyStateChecker is a helper class that takes a set of resource
 * some of which may be read only and queries the user as to whether or
 * not they wish to continue the operation on it.
 */
public class ReadOnlyStateChecker {
    private Shell shell;

    private String titleMessage;

    private String mainMessage;

    private boolean yesToAllSelected = false;

    private boolean cancelSelected = false;

    private boolean ignoreLinkedResources = false;
    
    private String READ_ONLY_EXCEPTION_MESSAGE = IDEWorkbenchMessages.ReadOnlyCheck_problems;

    /**
     * Create a new checker that parents the dialog off of parent using the supplied
     * title and message.
     * @param parent the shell used for dialogs
     * @param title the title for dialogs
     * @param message the message for a dialog - this will be prefaced with the name of the resource.
     */
    public ReadOnlyStateChecker(Shell parent, String title, String message) {
        this.shell = parent;
        this.titleMessage = title;
        this.mainMessage = message;
    }

    /**
     * Check an individual resource to see if it passed the read only query. If it is a file
     * just add it, otherwise it is a container and the children need to be checked too.
     * Return true if all items are selected and false if any are skipped.
     */
    private boolean checkAcceptedResource(IResource resourceToCheck,
            List selectedChildren) throws CoreException {

        if (resourceToCheck.getType() == IResource.FILE) {
			selectedChildren.add(resourceToCheck);
		} else if (getIgnoreLinkedResources() && resourceToCheck.isLinked()) {
            selectedChildren.add(resourceToCheck);
        }
        else {
        	IContainer container = (IContainer) resourceToCheck;
        	// if the project is closed, there's no point in checking
        	// it's children.  bug 99858
			if (container.isAccessible()) {
				// Now check below
				int childCheck = checkReadOnlyResources(container.members(),
						selectedChildren);
				// Add in the resource only if nothing was left out
				if (childCheck == IDialogConstants.YES_TO_ALL_ID) {
					selectedChildren.add(resourceToCheck);
				} else {
					// Something was left out - return false
					return false;
				}
			} else {
				selectedChildren.add(resourceToCheck);
			}
        }
        return true;

    }

    /**
     * Check the supplied resources to see if they are read only. If so then
	 * prompt the user to see if they can be deleted.Return those that were
	 * accepted.
	 * 
     * @param itemsToCheck
     * @return the resulting selected resources
     */
    public IResource[] checkReadOnlyResources(IResource[] itemsToCheck) {

        List selections = new ArrayList();
        int result = IDialogConstants.CANCEL_ID;
        try {
            result = checkReadOnlyResources(itemsToCheck, selections);
        } catch (final CoreException exception) {
            shell.getDisplay().syncExec(new Runnable() {
                public void run() {
                    ErrorDialog.openError(shell, READ_ONLY_EXCEPTION_MESSAGE,
                            null, exception.getStatus());
                }
            });
        }

        if (result == IDialogConstants.CANCEL_ID) {
			return new IResource[0];
		}

        //All were selected so return the original items
        if (result == IDialogConstants.YES_TO_ALL_ID) {
			return itemsToCheck;
		}

        IResource[] returnValue = new IResource[selections.size()];
        selections.toArray(returnValue);
        return returnValue;
    }

    /**
     * Check the children of the container to see if they are read only.
     * @return int
     * one of
     * 	YES_TO_ALL_ID - all elements were selected
     * 	NO_ID - No was hit at some point
     * 	CANCEL_ID - cancel was hit
     * @param itemsToCheck IResource[]
     * @param allSelected the List of currently selected resources to add to.
     */
    private int checkReadOnlyResources(IResource[] itemsToCheck,
            List allSelected) throws CoreException {

        //Shortcut. If the user has already selected yes to all then just return it
        if (yesToAllSelected) {
			return IDialogConstants.YES_TO_ALL_ID;
		}

        boolean noneSkipped = true;
        List selectedChildren = new ArrayList();

        for (int i = 0; i < itemsToCheck.length; i++) {
            IResource resourceToCheck = itemsToCheck[i];
            ResourceAttributes checkAttributes = resourceToCheck.getResourceAttributes();
            if (!yesToAllSelected && shouldCheck(resourceToCheck)
            		&& checkAttributes!=null
            		&& checkAttributes.isReadOnly()) {
                int action = queryYesToAllNoCancel(resourceToCheck);
                if (action == IDialogConstants.YES_ID) {
                    boolean childResult = checkAcceptedResource(
                            resourceToCheck, selectedChildren);
                    if (!childResult) {
						noneSkipped = false;
					}
                }
                if (action == IDialogConstants.NO_ID) {
					noneSkipped = false;
				}
                if (action == IDialogConstants.CANCEL_ID) {
                    cancelSelected = true;
                    return IDialogConstants.CANCEL_ID;
                }
                if (action == IDialogConstants.YES_TO_ALL_ID) {
                    yesToAllSelected = true;
                    selectedChildren.add(resourceToCheck);
                }
            } else {
                boolean childResult = checkAcceptedResource(resourceToCheck,
                        selectedChildren);
                if (cancelSelected) {
					return IDialogConstants.CANCEL_ID;
				}
                if (!childResult) {
					noneSkipped = false;
				}
            }

        }

        if (noneSkipped) {
			return IDialogConstants.YES_TO_ALL_ID;
		}
       allSelected.addAll(selectedChildren);
       return IDialogConstants.NO_ID;

    }

    /**
	 * Returns whether the given resource should be checked for read-only state.
	 * 
	 * @param resourceToCheck the resource to check
	 * @return <code>true</code> to check it, <code>false</code> to skip it
	 */
	private boolean shouldCheck(IResource resourceToCheck) {
        if (ignoreLinkedResources) {
        	if (resourceToCheck.isLinked()) {
				return false;
			}
        }
        return true;
    }

	/**
     * Open a message dialog with Yes No, Yes To All and Cancel buttons. Return the
     * code that indicates the selection.
     * @return int 
     *	one of
     *		YES_TO_ALL_ID
     *		YES_ID
     *		NO_ID
     *		CANCEL_ID
     * 		
     * @param resource - the resource being queried.
     */
    private int queryYesToAllNoCancel(IResource resource) {

        final MessageDialog dialog = new MessageDialog(this.shell,
                this.titleMessage, null, MessageFormat.format(this.mainMessage,
                        new Object[] { resource.getName() }),
                MessageDialog.QUESTION, new String[] {
                        IDialogConstants.YES_LABEL,
                        IDialogConstants.YES_TO_ALL_LABEL,
                        IDialogConstants.NO_LABEL,
                        IDialogConstants.CANCEL_LABEL }, 0) {
        	protected int getShellStyle() {
        		return super.getShellStyle() | SWT.SHEET;
        	}
        };
        shell.getDisplay().syncExec(new Runnable() {
            public void run() {
                dialog.open();
            }
        });
        int result = dialog.getReturnCode();
        if (result == 0) {
			return IDialogConstants.YES_ID;
		}
        if (result == 1) {
			return IDialogConstants.YES_TO_ALL_ID;
		}
        if (result == 2) {
			return IDialogConstants.NO_ID;
		}
        return IDialogConstants.CANCEL_ID;
    }
    
    /**
     * Returns whether to ignore linked resources.
     * 
     * @return <code>true</code> to ignore linked resources, <code>false</code> to consider them
     * @since 3.1
     */
    public boolean getIgnoreLinkedResources() {
    	return ignoreLinkedResources;
    }

    /**
     * Sets whether to ignore linked resources.
     * The default is <code>false</code>.
     * 
     * @param ignore <code>true</code> to ignore linked resources, <code>false</code> to consider them
     * @since 3.1
     */
    public void setIgnoreLinkedResources(boolean ignore) {
    	ignoreLinkedResources = ignore;
    }
}
