/******************************************************************************* 
 * Copyright (c) 2000, 2003 IBM Corporation and others. 
 * All rights reserved. This program and the accompanying materials! 
 * are made available under the terms of the Common Public License v1.0 
 * which accompanies this distribution, and is available at 
 * http://www.eclipse.org/legal/cpl-v10.html 
 * 
 * Contributors: 
 *   IBM Corporation - initial API and implementation 
 *   Sebastian Davids <sdavids@gmx.de> - Fix for bug 19346 - Dialog font
 * 		should be activated and used by other components.
************************************************************************/
package org.eclipse.ui.internal.ide.dialogs;

import java.io.File;
import java.util.Set;
import org.eclipse.core.resources.IPathVariableManager;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.dialogs.*;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;

/**
 * Dialog that prompts the user for defining a variable's name and value. It
 * supports creating a new variable or editing an existing one. The difference
 * between the two uses is just a matter of which messages to present to the
 * user and whether the "Ok" button starts enabled or not.
 */
public class PathVariableDialog extends TitleAreaDialog {

	// UI widgets
	private Button okButton;
	private Label variableNameLabel;
	private Label variableValueLabel;
	private Text variableNameField;
	private Text variableValueField;
	private Button fileButton;
	private Button folderButton;

	/**
	 * This dialog type: <code>NEW_VARIABLE</code> or
	 * <code>EXISTING_VARIABLE</code>.
	 */
	private int type;
	/**
	 * The type of variable that can be edited in this dialog.
	 * <code>IResource.FILE</code> or <code>IResource.FOLDER</code>
	 */
	private int variableType;
	/**
	 * The name of the variable being edited.
	 */
	private String variableName;
	/**
	 * The value of the variable being edited.
	 */
	private String variableValue;
	/**
	 * The original name of the variable being edited. It is used when testing
	 * if the current variable's name is already in use.
	 */
	private String originalName;

	/**
	 * Used to select the proper message depending on the current mode
	 * (new/existing variable).
	 */
	private String typeKeySuffix;

	/**
	 * Reference to the path variable manager. It is used for validating
	 * variable names.
	 */
	private IPathVariableManager pathVariableManager;

	/**
	 * Set of variable names currently in use. Used when warning the user that
	 * the currently selected name is already in use by another variable.
	 */
	private Set namesInUse;

	/**
	 * The current validation status. Its value can be one of the following:<ul>
	 * <li><code>IMessageProvider.NONE</code> (default);</li>
	 * <li><code>IMessageProvider.WARNING</code>;</li>
	 * <li><code>IMessageProvider.ERROR</code>;</li>
	 * </ul>
	 * Used when validating the user input.
	 */
	private int validationStatus;

	/**
	 * The current validation message generated by the last
	 * call to a <code>validate</code> method.
	 */
	private String validationMessage;

	/**
	 * Whether a variable name has been entered.  
	 */
	private boolean nameEntered = false;

	/**
	 * Whether a variable location has been entered.  
	 */
	private boolean locationEntered = false;
	
	/**
	 * The standard message to be shown when there are no problems being
	 * reported.
	 */
	final private String standardMessage;

	/**
	 * Constant for defining this dialog as intended to create a new variable
	 * (value = 1).
	 */
	public final static int NEW_VARIABLE = 1;
	/**
	 * Constant for defining this dialog as intended to edit an existing
	 * variable (value = 2).
	 */
	public final static int EXISTING_VARIABLE = 2;

	/**
	 * Constructs a dialog for editing a new/existing path variable.
	 * 
	 * @param parentShell the parent shell
	 * @param type the dialog type: <code>NEW_VARIABLE</code> or
	 * 	<code>EXISTING_VARIABLE</code>
	 * @param variableType the type of variable that can be edited in 
	 * 	this dialog. <code>IResource.FILE</code> or <code>IResource.FOLDER</code>
	 * @param pathVariableManager a reference to the path variable manager
	 * @param namesInUse a set of variable names currently in use 
	 */
	public PathVariableDialog(Shell parentShell, int type, int variableType, IPathVariableManager pathVariableManager, Set namesInUse) {
		super(parentShell);
		this.type = type;
		this.typeKeySuffix = type == NEW_VARIABLE ? "newVariable" : "existingVariable"; //$NON-NLS-1$ //$NON-NLS-2$        
		this.variableName = ""; //$NON-NLS-1$
		this.variableValue = ""; //$NON-NLS-1$
		this.variableType = variableType;
		this.pathVariableManager = pathVariableManager;
		this.namesInUse = namesInUse;

		this.standardMessage = IDEWorkbenchMessages.getString("PathVariableDialog.message." + typeKeySuffix); //$NON-NLS-1$
	}
	/**
	 * Configures this dialog's shell, setting the shell's text.
	 * 
	 * @see org.eclipse.jface.window.Window#configureShell(Shell)
	 */
	protected void configureShell(Shell shell) {
		super.configureShell(shell);
		shell.setText(IDEWorkbenchMessages.getString("PathVariableDialog.shellTitle." + typeKeySuffix)); //$NON-NLS-1$
	}
	/**
	 * Creates and returns the contents of this dialog (except for the button bar).
	 * 
	 * @see org.eclipse.jface.dialogs.TitleAreaDialog#createDialogArea
	 */
	protected Control createDialogArea(Composite parent) {
		// top level composite
		Composite parentComposite = (Composite) super.createDialogArea(parent);

		// creates dialog area composite
		Composite contents = createComposite(parentComposite);

		// creates and lay outs dialog area widgets 
		createWidgets(contents, parent.getFont());

		// validate possibly already incorrect variable definitions
		if (type == EXISTING_VARIABLE) {
			nameEntered = locationEntered = true;
			validateVariableValue();
		}

		return contents;
	}

	/**
	 * Creates and configures this dialog's main composite.
	 * 
	 * @param parentComposite parent's composite
	 * @return this dialog's main composite
	 */
	private Composite createComposite(Composite parentComposite) {
		// creates a composite with standard margins and spacing
		Composite contents = new Composite(parentComposite, SWT.NONE);

		FormLayout layout = new FormLayout();

		layout.marginHeight = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN);
		layout.marginWidth = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN);

		contents.setLayout(layout);
		contents.setFont(parentComposite.getFont());

		setTitle(IDEWorkbenchMessages.getString("PathVariableDialog.dialogTitle." + typeKeySuffix)); //$NON-NLS-1$
		setMessage(standardMessage);
		return contents;
	}

	/**
	 * Creates widgets for this dialog.
	 * 
	 * @param parent the parent composite where to create widgets
	 * @param contents 
	 */
	private void createWidgets(Composite contents, Font font) {
		FormData data;

		String nameLabelText = IDEWorkbenchMessages.getString("PathVariableDialog.variableName"); //$NON-NLS-1$
		String valueLabelText = IDEWorkbenchMessages.getString("PathVariableDialog.variableValue"); //$NON-NLS-1$

		// variable name label
		variableNameLabel = new Label(contents, SWT.LEFT);
		variableNameLabel.setText(nameLabelText);

		data = new FormData();
		variableNameLabel.setLayoutData(data);
		variableNameLabel.setFont(font);

		// variable value label
		variableValueLabel = new Label(contents, SWT.LEFT);
		variableValueLabel.setText(valueLabelText);

		data = new FormData();
		data.top = new FormAttachment(variableNameLabel, convertVerticalDLUsToPixels(10));
		variableValueLabel.setLayoutData(data);
		variableValueLabel.setFont(font);

		// the larger label will be used in the left attachments for the fields  
		Label largerLabel = nameLabelText.length() > valueLabelText.length() ? variableNameLabel : variableValueLabel;

		// variable name field
		variableNameField = new Text(contents, SWT.SINGLE | SWT.BORDER);
		variableNameField.setText(variableName);

		data = new FormData();
		data.width = convertWidthInCharsToPixels(50);
		data.left = new FormAttachment(largerLabel, convertHorizontalDLUsToPixels(5));
		variableNameField.setLayoutData(data);
		variableNameField.setFont(font);
		variableNameField.setFocus();

		variableNameField.addModifyListener(new ModifyListener() {
			public void modifyText(ModifyEvent event) {
				variableNameModified();
			}
		});

		// variable value field
		variableValueField = new Text(contents, SWT.SINGLE | SWT.BORDER);
		variableValueField.setText(variableValue);

		data = new FormData();
		data.width = convertWidthInCharsToPixels(50);
		data.left = new FormAttachment(largerLabel, convertHorizontalDLUsToPixels(5));
		data.top = new FormAttachment(variableNameLabel, convertVerticalDLUsToPixels(10));
		variableValueField.setLayoutData(data);
		variableValueField.setFont(font);
		
		variableValueField.addModifyListener(new ModifyListener() {
			public void modifyText(ModifyEvent event) {
				variableValueModified();
			}
		});

		// select file path button
		fileButton = new Button(contents, SWT.PUSH);
		fileButton.setText(IDEWorkbenchMessages.getString("PathVariableDialog.file")); //$NON-NLS-1$
		if ((variableType & IResource.FILE) == 0)
			fileButton.setEnabled(false);

		data = setButtonFormLayoutData(fileButton);
		data.top = new FormAttachment(variableNameLabel, convertVerticalDLUsToPixels(10));
		data.left = new FormAttachment(variableValueField, convertHorizontalDLUsToPixels(10));
		data.right = new FormAttachment(100, -5);
		fileButton.setLayoutData(data);
		fileButton.setFont(font);

		fileButton.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent e) {
				selectFile();
			}
		});

		// select folder path button
		folderButton = new Button(contents, SWT.PUSH);
		folderButton.setText(IDEWorkbenchMessages.getString("PathVariableDialog.folder")); //$NON-NLS-1$
		if ((variableType & IResource.FOLDER) == 0)
			folderButton.setEnabled(false);

		data = setButtonFormLayoutData(folderButton);
		data.top = new FormAttachment(variableValueLabel, convertVerticalDLUsToPixels(10));
		data.left = new FormAttachment(variableValueField, convertHorizontalDLUsToPixels(10));
		data.right = new FormAttachment(100, -5);
		folderButton.setLayoutData(data);
		folderButton.setFont(font);

		folderButton.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent e) {
				selectFolder();
			}
		});
	}

	/**
	 * Sets the <code>FormData</code> on the specified button to be one that is
	 * spaced for the current dialog page units. The method
	 * <code>initializeDialogUnits</code> must be called once before calling this
	 * method for the first time.
	 * 
	 * @param button the button to set the <code>FormData</code>
	 * @return the <code>FormData</code> set on the specified button
	 */
	private FormData setButtonFormLayoutData(Button button) {
		FormData data = new FormData();
		data.height = convertVerticalDLUsToPixels(IDialogConstants.BUTTON_HEIGHT);
		int widthHint = convertHorizontalDLUsToPixels(IDialogConstants.BUTTON_WIDTH);
		data.width = Math.max(widthHint, button.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x);
		button.setLayoutData(data);
		return data;
	}

	/**
	 * Fires validations (variable name first) and updates enabled state for the
	 * "Ok" button accordingly.
	 */
	private void variableNameModified() {
		// updates and validates the variable name
		variableName = variableNameField.getText().trim();
		validationStatus = IMessageProvider.NONE;
		okButton.setEnabled(validateVariableName() && validateVariableValue());
		nameEntered = true;
	}
	/**
	 * Fires validations (variable value first) and updates enabled state for the
	 * "Ok" button accordingly.
	 */
	private void variableValueModified() {
		// updates and validates the variable value
		variableValue = variableValueField.getText().trim();
		validationStatus = IMessageProvider.NONE;
		okButton.setEnabled(validateVariableValue() && validateVariableName());
		locationEntered = true;
	}

	/**
	 * Opens a dialog where the user can select a folder path.
	 */
	private void selectFolder() {
		DirectoryDialog dialog = new DirectoryDialog(getShell());
		dialog.setText(IDEWorkbenchMessages.getString("PathVariableDialog.selectFolderTitle")); //$NON-NLS-1$
		dialog.setMessage(IDEWorkbenchMessages.getString("PathVariableDialog.selectFolderMessage")); //$NON-NLS-1$
		dialog.setFilterPath(variableValue);
		String res = dialog.open();
		if (res != null) {
			variableValue = new Path(res).makeAbsolute().toOSString();
			variableValueField.setText(variableValue);
		}
	}

	/**
	 * Opens a dialog where the user can select a file path.
	 */
	private void selectFile() {
		FileDialog dialog = new FileDialog(getShell());
		dialog.setText(IDEWorkbenchMessages.getString("PathVariableDialog.selectFileTitle")); //$NON-NLS-1$
		dialog.setFilterPath(variableValue);
		String res = dialog.open();
		if (res != null) {
			variableValue = new Path(res).makeAbsolute().toOSString();
			variableValueField.setText(variableValue);
		}
	}

	/**
	 * Adds buttons to this dialog's button bar.
	 * 
	 * @see org.eclipse.jface.dialogs.Dialog#createButtonsForButtonBar
	 */
	protected void createButtonsForButtonBar(Composite parent) {
		okButton = createButton(parent, IDialogConstants.OK_ID, IDialogConstants.OK_LABEL, true);
		okButton.setEnabled(type == EXISTING_VARIABLE);

		createButton(parent, IDialogConstants.CANCEL_ID, IDialogConstants.CANCEL_LABEL, false);
	}

	/**
	 * Validates the current variable name, and updates this dialog's message.
	 * 
	 * @return true if the name is valid, false otherwise
	 */
	private boolean validateVariableName() {
		boolean allowFinish = false;
		
		// if the current validationStatus is ERROR, no additional validation applies
		if (validationStatus == IMessageProvider.ERROR)
			return false;

		// assumes everything will be ok
		String message = standardMessage;
		int newValidationStatus = IMessageProvider.NONE;

		if (variableName.length() == 0) {
			// the variable name is empty
			if (nameEntered) {
				// a name was entered before and is now empty
				newValidationStatus = IMessageProvider.ERROR;				
				message = IDEWorkbenchMessages.getString("PathVariableDialog.variableNameEmptyMessage"); //$NON-NLS-1$
			}
		} else {
			IStatus status = pathVariableManager.validateName(variableName);
			if (!status.isOK()) {
				// the variable name is not valid
				newValidationStatus = IMessageProvider.ERROR;
				message = status.getMessage();
			} else if (namesInUse.contains(variableName) && !variableName.equals(originalName)) {
				// the variable name is already in use
				message = IDEWorkbenchMessages.getString("PathVariableDialog.variableAlreadyExistsMessage"); //$NON-NLS-1$
				newValidationStatus = IMessageProvider.ERROR;
			} else {
				allowFinish = true;
			}
		}

		// overwrite the current validation status / message only if everything is ok (clearing them)
		// or if we have a more serious problem than the current one
		if (validationStatus == IMessageProvider.NONE || newValidationStatus == IMessageProvider.ERROR) {
			validationStatus = newValidationStatus;
			validationMessage = message;
		}
		// only set the message here if it is not going to be set in 
		// validateVariableValue to avoid flashing.
		if (allowFinish == false)
			setMessage(validationMessage, validationStatus);
		return allowFinish;
	}

	/**
	 * Validates the current variable value, and updates this dialog's message.
	 * 
	 * @return true if the value is valid, false otherwise
	 */
	private boolean validateVariableValue() {
		boolean allowFinish = false;

		// if the current validationStatus is ERROR, no additional validation applies
		if (validationStatus == IMessageProvider.ERROR)
			return false;

		// assumes everything will be ok
		String message = standardMessage;
		int newValidationStatus = IMessageProvider.NONE;

		if (variableValue.length() == 0) {
			// the variable value is empty
			if (locationEntered) {
				// a location value was entered before and is now empty
				newValidationStatus = IMessageProvider.ERROR;
				message = IDEWorkbenchMessages.getString("PathVariableDialog.variableValueEmptyMessage"); //$NON-NLS-1$
			}			
		} else if (!Path.EMPTY.isValidPath(variableValue)) {
			// the variable value is an invalid path
			message = IDEWorkbenchMessages.getString("PathVariableDialog.variableValueInvalidMessage"); //$NON-NLS-1$
			newValidationStatus = IMessageProvider.ERROR;
		} else if (!new Path(variableValue).isAbsolute()) {
			// the variable value is a relative path
			message = IDEWorkbenchMessages.getString("PathVariableDialog.pathIsRelativeMessage"); //$NON-NLS-1$
			newValidationStatus = IMessageProvider.ERROR;
		} else if (!new File(variableValue).exists()) {
			// the path does not exist (warning)
			message = IDEWorkbenchMessages.getString("PathVariableDialog.pathDoesNotExistMessage"); //$NON-NLS-1$
			newValidationStatus = IMessageProvider.WARNING;
			allowFinish = true;
		} else {
			allowFinish = true;
		}

		// overwrite the current validation status / message only if everything is ok (clearing them)
		// or if we have a more serious problem than the current one
		if (validationStatus == IMessageProvider.NONE || newValidationStatus > validationStatus) {
			validationStatus = newValidationStatus;
			validationMessage = message;
		}
		setMessage(validationMessage, validationStatus);		
		return allowFinish;
	}

	/**
	 * Returns the variable name.
	 * 
	 * @return the variable name
	 */
	public String getVariableName() {
		return variableName;
	}

	/**
	 * Returns the variable value.
	 * 
	 * @return the variable value
	 */
	public String getVariableValue() {
		return variableValue;
	}

	/**
	 * Sets the variable name.
	 * 
	 * @param variableName the new variable name
	 */
	public void setVariableName(String variableName) {
		this.variableName = variableName.trim();
		this.originalName = this.variableName;
	}

	/**
	 * Sets the variable value.
	 * 
	 * @param variableValue the new variable value
	 */
	public void setVariableValue(String variableValue) {
		this.variableValue = variableValue;
	}

}