/*******************************************************************************
 * Copyright (c) 2010, 2011 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.wst.xml.ui.internal.preferences;

import java.util.Vector;

import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.IWorkbenchPreferencePage;
import org.eclipse.wst.sse.ui.internal.Logger;
import org.eclipse.wst.sse.ui.internal.contentassist.CompletionProposoalCatigoriesConfigurationRegistry;
import org.eclipse.wst.sse.ui.internal.preferences.ui.AbstractPreferencePage;
import org.eclipse.wst.sse.ui.preferences.CodeAssistCyclingConfigurationBlock;
import org.eclipse.wst.sse.ui.preferences.ICompletionProposalCategoriesConfigurationWriter;
import org.eclipse.wst.xml.ui.internal.XMLUIMessages;
import org.eclipse.wst.xml.ui.internal.XMLUIPlugin;

/**
 * <p>Defines the preference page for allowing the user to change the content
 * assist preferences</p>
 */
public class XMLContentAssistPreferencePage extends AbstractPreferencePage implements
		IWorkbenchPreferencePage {

	private static final String XML_CONTENT_TYPE_ID = "org.eclipse.core.runtime.xml"; //$NON-NLS-1$
	
	// Auto Activation
	private Button fAutoPropose;
	private Label fAutoProposeDelayLabel;
	private Text fAutoProposeDelay;
	private Label fAutoProposeLabel;
	private Text fAutoProposeText;
	private Combo fSuggestionStrategyCombo;
	private Vector fSuggestionStrategies = null;
	
	/** configuration block for changing preference having to do with the content assist categories */
	private CodeAssistCyclingConfigurationBlock fConfigurationBlock;
	
	/**
	 * @see org.eclipse.wst.sse.ui.internal.preferences.ui.AbstractPreferencePage#createContents(org.eclipse.swt.widgets.Composite)
	 */
	protected Control createContents(Composite parent) {
		final Composite composite = super.createComposite(parent, 1);
		
		createContentsForAutoActivationGroup(composite);
		createContentsForCyclingGroup(composite);
		
		setSize(composite);
		loadPreferences();
		
		return composite;
	}
	
	/**
	 * @see org.eclipse.wst.sse.ui.internal.preferences.ui.AbstractPreferencePage#performDefaults()
	 */
	protected void performDefaults() {
		performDefaultsForAutoActivationGroup();
		performDefaultsForCyclingGroup();

		validateValues();
		enableValues();

		super.performDefaults();
	}
	
	/**
	 * @see org.eclipse.wst.sse.ui.internal.preferences.ui.AbstractPreferencePage#initializeValues()
	 */
	protected void initializeValues() {
		initializeValuesForAutoActivationGroup();
		initializeValuesForCyclingGroup();
	}
	
	/**
	 * @see org.eclipse.wst.sse.ui.internal.preferences.ui.AbstractPreferencePage#storeValues()
	 */
	protected void storeValues() {
		storeValuesForAutoActivationGroup();
		storeValuesForCyclingGroup();
	}
	
	/**
	 * @see org.eclipse.wst.sse.ui.internal.preferences.ui.AbstractPreferencePage#enableValues()
	 */
	protected void enableValues() {
		if (fAutoPropose != null) {
			if (fAutoPropose.getSelection()) {
				fAutoProposeDelayLabel.setEnabled(true);
				fAutoProposeDelay.setEnabled(true);
				fAutoProposeLabel.setEnabled(true);
				fAutoProposeText.setEnabled(true);
			}
			else {
				fAutoProposeDelayLabel.setEnabled(false);
				fAutoProposeDelay.setEnabled(false);
				fAutoProposeLabel.setEnabled(false);
				fAutoProposeText.setEnabled(false);
			}
		}
	}
	
	/**
	 * @see org.eclipse.jface.preference.PreferencePage#doGetPreferenceStore()
	 */
	protected IPreferenceStore doGetPreferenceStore() {
		return XMLUIPlugin.getDefault().getPreferenceStore();
	}

	/**
	 * <p>Create contents for the auto activation preference group</p>
	 * @param parent {@link Composite} parent of the group
	 */
	private void createContentsForAutoActivationGroup(Composite parent) {
		Group contentAssistGroup = createGroup(parent, 2);
		contentAssistGroup.setText(XMLUIMessages.XMLContentAssistPreferencePage_Auto_Activation_UI_);

		fAutoPropose = createCheckBox(contentAssistGroup, XMLUIMessages.Automatically_make_suggest_UI_);
		((GridData) fAutoPropose.getLayoutData()).horizontalSpan = 2;
		fAutoPropose.addSelectionListener(this);

		fAutoProposeDelayLabel = createLabel(contentAssistGroup, XMLUIMessages.Auto_Activation_Delay);
		fAutoProposeDelay = createTextField(contentAssistGroup);
		fAutoProposeDelay.setTextLimit(4);
		fAutoProposeDelay.addModifyListener(new ModifyListener() {
			
			public void modifyText(ModifyEvent e) {
				verifyDelay();
			}
		});
		

		fAutoProposeLabel = createLabel(contentAssistGroup, XMLUIMessages.Prompt_when_these_characte_UI_);
		fAutoProposeText = createTextField(contentAssistGroup);

		createLabel(contentAssistGroup, XMLUIMessages.Suggestion_Strategy);
		fSuggestionStrategyCombo = new Combo(contentAssistGroup, SWT.READ_ONLY);
		fSuggestionStrategies = new Vector();
		fSuggestionStrategyCombo.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
		fSuggestionStrategyCombo.add(XMLUIMessages.Suggestion_Strategy_Lax);
		fSuggestionStrategies.add(XMLUIPreferenceNames.SUGGESTION_STRATEGY_VALUE_LAX);
		fSuggestionStrategyCombo.add(XMLUIMessages.Suggestion_Strategy_Strict);
		fSuggestionStrategies.add(XMLUIPreferenceNames.SUGGESTION_STRATEGY_VALUE_STRICT);
	}
	
	private void verifyDelay() {
		final String text = fAutoProposeDelay.getText();
		boolean valid = true;
		try {
			final int delay = Integer.parseInt(text);
			if (delay < 0) {
				valid = false;
			}
		}
		catch (NumberFormatException e) {
			valid = false;
		}
		if (!valid) {
			if (text.trim().length() > 0)
				setErrorMessage(NLS.bind(XMLUIMessages.Not_an_integer, text));
			else
				setErrorMessage(XMLUIMessages.Missing_integer);
			setValid(false);
		}
		else {
			setErrorMessage(null);
			setValid(true);
		}
	}
	
	/**
	 * <p>Create the contents for the content assist cycling preference group</p>
	 * @param parent {@link Composite} parent of the group
	 */
	private void createContentsForCyclingGroup(Composite parent) {
		ICompletionProposalCategoriesConfigurationWriter configurationWriter = CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getWritableConfiguration(XML_CONTENT_TYPE_ID);
		
		if(configurationWriter != null) {
			fConfigurationBlock = new CodeAssistCyclingConfigurationBlock(XML_CONTENT_TYPE_ID, configurationWriter);
			fConfigurationBlock.createContents(parent, XMLUIMessages.XMLContentAssistPreferencePage_Cycling_UI_);
		} else {
			Logger.log(Logger.ERROR, "There should be an ICompletionProposalCategoriesConfigurationWriter" + //$NON-NLS-1$
					" specified for the XML content type, but can't fine it, thus can't create user" + //$NON-NLS-1$
					" preference block for editing proposal categories preferences."); //$NON-NLS-1$
		}
	}
	
	/**
	 * <p>Store the values for the auto activation group</p>
	 */
	private void storeValuesForAutoActivationGroup() {
		getPreferenceStore().setValue(XMLUIPreferenceNames.AUTO_PROPOSE, fAutoPropose.getSelection());
		getPreferenceStore().setValue(XMLUIPreferenceNames.AUTO_PROPOSE_CODE, fAutoProposeText.getText());
		getPreferenceStore().setValue(XMLUIPreferenceNames.SUGGESTION_STRATEGY, getCurrentAutoActivationSuggestionStrategy());
		getPreferenceStore().setValue(XMLUIPreferenceNames.AUTO_PROPOSE_DELAY, Integer.parseInt(fAutoProposeDelay.getText()));
	}
	
	/**
	 * <p>Store the values for the cycling group</p>
	 */
	private void storeValuesForCyclingGroup() {
		if (fConfigurationBlock != null) {
			fConfigurationBlock.storeValues();
		}
	}
	
	/**
	 * <p>Initialize the values for the auto activation group</p>
	 */
	private void initializeValuesForAutoActivationGroup() {
		fAutoPropose.setSelection(getPreferenceStore().getBoolean(XMLUIPreferenceNames.AUTO_PROPOSE));
		fAutoProposeText.setText(getPreferenceStore().getString(XMLUIPreferenceNames.AUTO_PROPOSE_CODE));
		fAutoProposeDelay.setText(Integer.toString(getPreferenceStore().getInt(XMLUIPreferenceNames.AUTO_PROPOSE_DELAY)));
		String suggestionStrategy = getPreferenceStore().getString(XMLUIPreferenceNames.SUGGESTION_STRATEGY);
		if (suggestionStrategy.length() > 0) {
			setCurrentAutoActivationSuggestionStrategy(suggestionStrategy);
		}
		else {
			setCurrentAutoActivationSuggestionStrategy(XMLUIPreferenceNames.SUGGESTION_STRATEGY_VALUE_LAX);
		}
	}
	
	/**
	 * <p>Initialize the values for the cycling group</p>
	 */
	private void initializeValuesForCyclingGroup() {
		if(fConfigurationBlock != null) {
			fConfigurationBlock.initializeValues();
		}
	}
	
	/**
	 * <p>Load the defaults for the auto activation group</p>
	 */
	private void performDefaultsForAutoActivationGroup() {
		fAutoPropose.setSelection(getPreferenceStore().getDefaultBoolean(XMLUIPreferenceNames.AUTO_PROPOSE));
		fAutoProposeText.setText(getPreferenceStore().getDefaultString(XMLUIPreferenceNames.AUTO_PROPOSE_CODE));
		fAutoProposeDelay.setText(Integer.toString(getPreferenceStore().getDefaultInt(XMLUIPreferenceNames.AUTO_PROPOSE_DELAY)));
		String suggestionStrategy = getPreferenceStore().getDefaultString(XMLUIPreferenceNames.SUGGESTION_STRATEGY);
		if (suggestionStrategy.length() > 0) {
			setCurrentAutoActivationSuggestionStrategy(suggestionStrategy);
		}
		else {
			setCurrentAutoActivationSuggestionStrategy(XMLUIPreferenceNames.SUGGESTION_STRATEGY_VALUE_LAX);
		}
	}
	
	/**
	 * <p>Load the defaults of the cycling group</p>
	 */
	private void performDefaultsForCyclingGroup() {
		if(fConfigurationBlock != null) {
			fConfigurationBlock.performDefaults();
		}
	}
	
	/**
	 * Return the currently selected suggestion strategy preference
	 * 
	 * @return a suggestion strategy constant from XMLUIPreferenceNames
	 */
	private String getCurrentAutoActivationSuggestionStrategy() {
		int i = fSuggestionStrategyCombo.getSelectionIndex();
		if (i >= 0) {
			return (String) (fSuggestionStrategies.elementAt(i));
		}
		return ""; //$NON-NLS-1$
	}
	
	/**
	 * Set a suggestion strategy in suggestion strategy combo box
	 * 
	 * @param strategy
	 */
	private void setCurrentAutoActivationSuggestionStrategy(String strategy) {
		// Clear the current selection.
		fSuggestionStrategyCombo.clearSelection();
		fSuggestionStrategyCombo.deselectAll();

		int i = fSuggestionStrategies.indexOf(strategy);
		if (i >= 0) {
			fSuggestionStrategyCombo.select(i);
		}
	}
}