/*******************************************************************************
 * Copyright (c) 2000, 2010 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
 *     Anton Leherbauer (Wind River Systems)
 *******************************************************************************/
package org.eclipse.cdt.internal.ui.preferences.formatter;

import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Observable;
import java.util.Observer;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.ProjectScope;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.preferences.IEclipsePreferences.IPreferenceChangeListener;
import org.eclipse.core.runtime.preferences.IEclipsePreferences.PreferenceChangeEvent;
import org.eclipse.core.runtime.preferences.IScopeContext;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.dialogs.StatusDialog;
import org.eclipse.jface.layout.PixelConverter;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.FileDialog;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.osgi.service.prefs.BackingStoreException;

import org.eclipse.cdt.core.CCorePlugin;
import org.eclipse.cdt.ui.CUIPlugin;

import org.eclipse.cdt.internal.corext.util.Messages;

import org.eclipse.cdt.internal.ui.preferences.PreferencesAccess;
import org.eclipse.cdt.internal.ui.preferences.formatter.ProfileManager.CustomProfile;
import org.eclipse.cdt.internal.ui.preferences.formatter.ProfileManager.Profile;
import org.eclipse.cdt.internal.ui.util.ExceptionHandler;
import org.eclipse.cdt.internal.ui.util.SWTUtil;

public abstract class ProfileConfigurationBlock {

	private class StoreUpdater implements Observer {

		public StoreUpdater() {
			fProfileManager.addObserver(this);
		}

		@Override
		public void update(Observable o, Object arg) {
			try {
				fPreferenceListenerEnabled= false;
    			final int value= ((Integer)arg).intValue();
    			switch (value) {
    			case ProfileManager.PROFILE_DELETED_EVENT:
    			case ProfileManager.PROFILE_RENAMED_EVENT:
    			case ProfileManager.PROFILE_CREATED_EVENT:
    			case ProfileManager.SETTINGS_CHANGED_EVENT:
    				try {
    					fProfileStore.writeProfiles(fProfileManager.getSortedProfiles(), fInstanceScope); // update profile store
    					fProfileManager.commitChanges(fCurrContext); 
    				} catch (CoreException x) {
    					CUIPlugin.log(x);
    				}
    				break;
    			case ProfileManager.SELECTION_CHANGED_EVENT:
    				fProfileManager.commitChanges(fCurrContext);
    				break;
    			}
			} finally {
				fPreferenceListenerEnabled= true;
			}
		}
	}

	class ProfileComboController implements Observer, SelectionListener {

		private final List<Profile> fSortedProfiles;

		public ProfileComboController() {
			fSortedProfiles= fProfileManager.getSortedProfiles();
			fProfileCombo.addSelectionListener(this);
			fProfileManager.addObserver(this);
			updateProfiles();
			updateSelection();
		}

		@Override
		public void widgetSelected(SelectionEvent e) {
			final int index= fProfileCombo.getSelectionIndex();
			fProfileManager.setSelected(fSortedProfiles.get(index));
		}

		@Override
		public void widgetDefaultSelected(SelectionEvent e) {}

		@Override
		public void update(Observable o, Object arg) {
			if (arg == null) return;
			final int value= ((Integer)arg).intValue();
			switch (value) {
			case ProfileManager.PROFILE_CREATED_EVENT:
			case ProfileManager.PROFILE_DELETED_EVENT:
			case ProfileManager.PROFILE_RENAMED_EVENT:
				updateProfiles();
				updateSelection();
				break;
			case ProfileManager.SELECTION_CHANGED_EVENT:
				updateSelection();
				break;
			}
		}

		private void updateProfiles() {
			fProfileCombo.setItems(fProfileManager.getSortedDisplayNames());
		}

		private void updateSelection() {
			fProfileCombo.setText(fProfileManager.getSelected().getName());
		}
	}

	class ButtonController implements Observer, SelectionListener {

		public ButtonController() {
			fProfileManager.addObserver(this);
			fNewButton.addSelectionListener(this);
			fEditButton.addSelectionListener(this);
			fDeleteButton.addSelectionListener(this);
			fLoadButton.addSelectionListener(this);
			update(fProfileManager, null);
		}

		@Override
		public void update(Observable o, Object arg) {
			Profile selected= ((ProfileManager)o).getSelected();
			final boolean notBuiltIn= !selected.isBuiltInProfile(); 
			fDeleteButton.setEnabled(notBuiltIn);
		}

		@Override
		public void widgetSelected(SelectionEvent e) {
			final Button button= (Button)e.widget;
			if (button == fEditButton)
				modifyButtonPressed();
			else if (button == fDeleteButton) 
				deleteButtonPressed();
			else if (button == fNewButton)
				newButtonPressed();
			else if (button == fLoadButton)
				loadButtonPressed();
		}

		@Override
		public void widgetDefaultSelected(SelectionEvent e) {
		}

		private void modifyButtonPressed() {
			final StatusDialog modifyDialog= createModifyDialog(fComposite.getShell(), fProfileManager.getSelected(), fProfileManager, fProfileStore, false);
			modifyDialog.open();
		}

		private void deleteButtonPressed() {
			if (MessageDialog.openQuestion(
					fComposite.getShell(), 
					FormatterMessages.CodingStyleConfigurationBlock_delete_confirmation_title, 
					Messages.format(FormatterMessages.CodingStyleConfigurationBlock_delete_confirmation_question, fProfileManager.getSelected().getName()))) { 
				fProfileManager.deleteSelected();
			}
		}

		private void newButtonPressed() {
			final CreateProfileDialog p= new CreateProfileDialog(fComposite.getShell(), fProfileManager, fProfileVersioner);
			if (p.open() != Window.OK) 
				return;
			if (!p.openEditDialog()) 
				return;
			final StatusDialog modifyDialog= createModifyDialog(fComposite.getShell(), p.getCreatedProfile(), fProfileManager, fProfileStore, true);
			modifyDialog.open();
		}

		private void loadButtonPressed() {
			final FileDialog dialog= new FileDialog(fComposite.getShell(), SWT.OPEN);
			dialog.setText(FormatterMessages.CodingStyleConfigurationBlock_load_profile_dialog_title); 
			dialog.setFilterExtensions(new String [] {"*.xml"}); //$NON-NLS-1$
			final String lastPath= CUIPlugin.getDefault().getDialogSettings().get(fLastSaveLoadPathKey + ".loadpath"); //$NON-NLS-1$
			if (lastPath != null) {
				dialog.setFilterPath(lastPath);
			}
			final String path= dialog.open();
			if (path == null) 
				return;
			CUIPlugin.getDefault().getDialogSettings().put(fLastSaveLoadPathKey + ".loadpath", dialog.getFilterPath()); //$NON-NLS-1$

			final File file= new File(path);
			Collection<Profile> profiles= null;
			try {
				profiles= fProfileStore.readProfilesFromFile(file);
			} catch (CoreException e) {
				final String title= FormatterMessages.CodingStyleConfigurationBlock_load_profile_error_title; 
				final String message= FormatterMessages.CodingStyleConfigurationBlock_load_profile_error_message; 
				ExceptionHandler.handle(e, fComposite.getShell(), title, message);
			}
			if (profiles == null || profiles.isEmpty())
				return;

			final CustomProfile profile= (CustomProfile)profiles.iterator().next();
			
			if (!fProfileVersioner.getProfileKind().equals(profile.getKind())) {
				final String title= FormatterMessages.CodingStyleConfigurationBlock_load_profile_error_title; 
				final String message= Messages.format(FormatterMessages.ProfileConfigurationBlock_load_profile_wrong_profile_message, new String[] {fProfileVersioner.getProfileKind(), profile.getKind()});
				MessageDialog.openError(fComposite.getShell(), title, message);
				return;
			}

			if (profile.getVersion() > fProfileVersioner.getCurrentVersion()) {
				final String title= FormatterMessages.CodingStyleConfigurationBlock_load_profile_error_too_new_title; 
				final String message= FormatterMessages.CodingStyleConfigurationBlock_load_profile_error_too_new_message; 
				MessageDialog.openWarning(fComposite.getShell(), title, message);
			}

			if (fProfileManager.containsName(profile.getName())) {
				final AlreadyExistsDialog aeDialog= new AlreadyExistsDialog(fComposite.getShell(), profile, fProfileManager);
				if (aeDialog.open() != Window.OK) 
					return;
			}
			fProfileVersioner.update(profile);
			fProfileManager.addProfile(profile);
		}
	}

	/**
	 * The GUI controls
	 */
	private Composite fComposite;
	private Combo fProfileCombo;
	private Button fEditButton;
	private Button fDeleteButton;
	private Button fNewButton;
	private Button fLoadButton;
	
	private PixelConverter fPixConv;
	/**
	 * The ProfileManager, the model of this page.
	 */
	private final ProfileManager fProfileManager;
	private final IScopeContext fCurrContext;
	private final IScopeContext fInstanceScope;
	private final ProfileStore fProfileStore;
	private final IProfileVersioner fProfileVersioner;
	private final String fLastSaveLoadPathKey;
	private IPreferenceChangeListener fPreferenceListener;
	private final PreferencesAccess fPreferenceAccess;
	private boolean fPreferenceListenerEnabled;

	public ProfileConfigurationBlock(IProject project, final PreferencesAccess access, String lastSaveLoadPathKey) {

		fPreferenceAccess= access;
		fLastSaveLoadPathKey= lastSaveLoadPathKey;

		fProfileVersioner= createProfileVersioner();
		fProfileStore= createProfileStore(fProfileVersioner);
		fInstanceScope= access.getInstanceScope();
		if (project != null) {
			fCurrContext= access.getProjectScope(project);
		} else {
			fCurrContext= fInstanceScope;
		}

		List<Profile> profiles= null;
        try {
            profiles= fProfileStore.readProfiles(fInstanceScope);
        } catch (CoreException e) {
        	CUIPlugin.log(e);
        }
        
        if (profiles == null) 
            profiles= new ArrayList<Profile>();

		fProfileManager= createProfileManager(profiles, fCurrContext, access, fProfileVersioner);

		new StoreUpdater();
		
		fPreferenceListenerEnabled= true;
		fPreferenceListener= new IPreferenceChangeListener() {
			@Override
			public void preferenceChange(PreferenceChangeEvent event) {
				if (fPreferenceListenerEnabled) {
					preferenceChanged(event);
				}
			}
		};
		access.getInstanceScope().getNode(CUIPlugin.PLUGIN_ID).addPreferenceChangeListener(fPreferenceListener);

	}

	protected void preferenceChanged(PreferenceChangeEvent event) {
		
	}

	protected abstract IProfileVersioner createProfileVersioner();
	
	protected abstract ProfileStore createProfileStore(IProfileVersioner versioner);
	
	protected abstract ProfileManager createProfileManager(List<Profile> profiles, IScopeContext context, PreferencesAccess access, IProfileVersioner profileVersioner);
	
	protected abstract ModifyDialog createModifyDialog(Shell shell, Profile profile, ProfileManager profileManager, ProfileStore profileStore, boolean newProfile);

	protected abstract void configurePreview(Composite composite, int numColumns, ProfileManager profileManager);

	private static Button createButton(Composite composite, String text, final int style) {
		final Button button= new Button(composite, SWT.PUSH);
		button.setFont(composite.getFont());
		button.setText(text);

		final GridData gd= new GridData(style);
		gd.widthHint= SWTUtil.getButtonWidthHint(button);
		button.setLayoutData(gd);
		return button;
	}

	/**
	 * Create the contents
	 * @param parent Parent composite
	 * @return Created control
	 */
	public Composite createContents(Composite parent) {

		final int numColumns = 5;

		fPixConv = new PixelConverter(parent);
		fComposite = createComposite(parent, numColumns);

		fProfileCombo= createProfileCombo(fComposite, 3, fPixConv.convertWidthInCharsToPixels(20));
		fEditButton= createButton(fComposite, FormatterMessages.CodingStyleConfigurationBlock_edit_button_desc, GridData.HORIZONTAL_ALIGN_BEGINNING);  
		fDeleteButton= createButton(fComposite, FormatterMessages.CodingStyleConfigurationBlock_remove_button_desc, GridData.HORIZONTAL_ALIGN_BEGINNING); 

		fNewButton= createButton(fComposite, FormatterMessages.CodingStyleConfigurationBlock_new_button_desc, GridData.HORIZONTAL_ALIGN_BEGINNING);
		fLoadButton= createButton(fComposite, FormatterMessages.CodingStyleConfigurationBlock_load_button_desc, GridData.HORIZONTAL_ALIGN_END);
		createLabel(fComposite, "", 3); //$NON-NLS-1$

		configurePreview(fComposite, numColumns, fProfileManager);

		new ButtonController();
		new ProfileComboController();

		return fComposite;
	}

	private static Combo createProfileCombo(Composite composite, int span, int widthHint) {
		final GridData gd = new GridData(GridData.FILL_HORIZONTAL);
		gd.horizontalSpan = span;
		gd.widthHint= widthHint;

		final Combo combo= new Combo(composite, SWT.DROP_DOWN | SWT.READ_ONLY );
		combo.setFont(composite.getFont());
		combo.setLayoutData(gd);
		return combo;
	}

	protected static Label createLabel(Composite composite, String text, int numColumns) {
		final GridData gd = new GridData(GridData.HORIZONTAL_ALIGN_FILL);
		gd.horizontalSpan = numColumns;
		gd.widthHint= 0;

		final Label label = new Label(composite, SWT.WRAP);
		label.setFont(composite.getFont());
		label.setText(text);
		label.setLayoutData(gd);
		return label;		
	}

	private Composite createComposite(Composite parent, int numColumns) {
		final Composite composite = new Composite(parent, SWT.NONE);
		composite.setFont(parent.getFont());

		final GridLayout layout = new GridLayout(numColumns, false);
		layout.marginHeight = 0;
		layout.marginWidth = 0;
		composite.setLayout(layout);
		return composite;
	}

	public final boolean hasProjectSpecificOptions(IProject project) {
		if (project != null) {
			return fProfileManager.hasProjectSpecificSettings(new ProjectScope(project));
		}
		return false;
	}

	public boolean performOk() {
		return true;
	}

	public void performApply() {
		try {
			fCurrContext.getNode(CUIPlugin.PLUGIN_ID).flush();
			fCurrContext.getNode(CCorePlugin.PLUGIN_ID).flush();
			if (fCurrContext != fInstanceScope) {
				fInstanceScope.getNode(CUIPlugin.PLUGIN_ID).flush();
				fInstanceScope.getNode(CCorePlugin.PLUGIN_ID).flush();
			}
		} catch (BackingStoreException e) {
			CUIPlugin.log(e);
		}
	}

	public void performDefaults() {
		Profile profile= fProfileManager.getDefaultProfile();
		if (profile != null) {
			int defaultIndex= fProfileManager.getSortedProfiles().indexOf(profile);
			if (defaultIndex != -1) {
				fProfileManager.setSelected(profile);
			}
		}
	}

	public void dispose() {
		if (fPreferenceListener != null) {
			fPreferenceAccess.getInstanceScope().getNode(CUIPlugin.PLUGIN_ID).removePreferenceChangeListener(fPreferenceListener);
			fPreferenceListener= null;
		}
	}

	public void enableProjectSpecificSettings(boolean useProjectSpecificSettings) {
		if (useProjectSpecificSettings) {
			fProfileManager.commitChanges(fCurrContext);
		} else {
			fProfileManager.clearAllSettings(fCurrContext);
		}
	}

}
