/*******************************************************************************
 * Copyright (c) 2000, 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.jdt.internal.ui.preferences;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;

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.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Link;

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IStatus;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;

import org.eclipse.jface.dialogs.ControlEnableState;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.preference.PreferencePage;
import org.eclipse.jface.window.Window;

import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPreferencePage;
import org.eclipse.ui.IWorkbenchPropertyPage;
import org.eclipse.ui.dialogs.PreferencesUtil;

import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;

import org.eclipse.jdt.internal.ui.dialogs.StatusInfo;
import org.eclipse.jdt.internal.ui.dialogs.StatusUtil;
import org.eclipse.jdt.internal.ui.wizards.IStatusChangeListener;
import org.eclipse.jdt.internal.ui.wizards.dialogfields.DialogField;
import org.eclipse.jdt.internal.ui.wizards.dialogfields.IDialogFieldListener;
import org.eclipse.jdt.internal.ui.wizards.dialogfields.LayoutUtil;
import org.eclipse.jdt.internal.ui.wizards.dialogfields.SelectionButtonDialogField;

/**
 * Base for project property and preference pages
 */
public abstract class PropertyAndPreferencePage extends PreferencePage implements IWorkbenchPreferencePage, IWorkbenchPropertyPage {

	private Control fConfigurationBlockControl;
	private ControlEnableState fBlockEnableState;
	private Link fChangeWorkspaceSettings;
	private SelectionButtonDialogField fUseProjectSettings;
	private IStatus fBlockStatus;
	private Composite fParentComposite;

	private IProject fProject; // project or null
	private Map<String, Object> fData; // page data

	public static final String DATA_NO_LINK= "PropertyAndPreferencePage.nolink"; //$NON-NLS-1$

	public PropertyAndPreferencePage() {
		fBlockStatus= new StatusInfo();
		fBlockEnableState= null;
		fProject= null;
		fData= null;
	}

	protected abstract Control createPreferenceContent(Composite composite);
	protected abstract boolean hasProjectSpecificOptions(IProject project);

	protected abstract String getPreferencePageID();
	protected abstract String getPropertyPageID();

	protected boolean supportsProjectSpecificOptions() {
		return getPropertyPageID() != null;
	}

	protected boolean offerLink() {
		return fData == null || !Boolean.TRUE.equals(fData.get(DATA_NO_LINK));
	}

    @Override
	protected Label createDescriptionLabel(Composite parent) {
		fParentComposite= parent;
		if (isProjectPreferencePage()) {
			Composite composite= new Composite(parent, SWT.NONE);
			composite.setFont(parent.getFont());
			GridLayout layout= new GridLayout();
			layout.marginHeight= 0;
			layout.marginWidth= 0;
			layout.numColumns= 2;
			composite.setLayout(layout);
			composite.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));

			IDialogFieldListener listener= new IDialogFieldListener() {
				public void dialogFieldChanged(DialogField field) {
					boolean enabled= ((SelectionButtonDialogField) field).isSelected();
					enableProjectSpecificSettings(enabled);

					if (enabled && getData() != null) {
						applyData(getData());
					}
				}
			};

			fUseProjectSettings= new SelectionButtonDialogField(SWT.CHECK);
			fUseProjectSettings.setDialogFieldListener(listener);
			fUseProjectSettings.setLabelText(PreferencesMessages.PropertyAndPreferencePage_useprojectsettings_label);
			fUseProjectSettings.doFillIntoGrid(composite, 1);
			LayoutUtil.setHorizontalGrabbing(fUseProjectSettings.getSelectionButton(null));

			if (offerLink()) {
				fChangeWorkspaceSettings= createLink(composite, PreferencesMessages.PropertyAndPreferencePage_useworkspacesettings_change);
				fChangeWorkspaceSettings.setLayoutData(new GridData(SWT.END, SWT.CENTER, false, false));
			} else {
				LayoutUtil.setHorizontalSpan(fUseProjectSettings.getSelectionButton(null), 2);
			}

			Label horizontalLine= new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL);
			horizontalLine.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, false, 2, 1));
			horizontalLine.setFont(composite.getFont());
		} else if (supportsProjectSpecificOptions() && offerLink()) {
			fChangeWorkspaceSettings= createLink(parent, PreferencesMessages.PropertyAndPreferencePage_showprojectspecificsettings_label);
			fChangeWorkspaceSettings.setLayoutData(new GridData(SWT.END, SWT.CENTER, true, false));
		}

		return super.createDescriptionLabel(parent);
    }

	/*
	 * @see org.eclipse.jface.preference.IPreferencePage#createContents(Composite)
	 */
	@Override
	protected Control createContents(Composite parent) {
		Composite composite= new Composite(parent, SWT.NONE);
		GridLayout layout= new GridLayout();
		layout.marginHeight= 0;
		layout.marginWidth= 0;
		composite.setLayout(layout);
		composite.setFont(parent.getFont());

		GridData data= new GridData(GridData.FILL, GridData.FILL, true, true);

		fConfigurationBlockControl= createPreferenceContent(composite);
		fConfigurationBlockControl.setLayoutData(data);

		if (isProjectPreferencePage()) {
			boolean useProjectSettings= hasProjectSpecificOptions(getProject());
			enableProjectSpecificSettings(useProjectSettings);
		}

		Dialog.applyDialogFont(composite);
		return composite;
	}

	private Link createLink(Composite composite, String text) {
		Link link= new Link(composite, SWT.NONE);
		link.setFont(composite.getFont());
		link.setText("<A>" + text + "</A>");  //$NON-NLS-1$//$NON-NLS-2$
		link.addSelectionListener(new SelectionListener() {
			public void widgetSelected(SelectionEvent e) {
				doLinkActivated((Link) e.widget);
			}

			public void widgetDefaultSelected(SelectionEvent e) {
				doLinkActivated((Link) e.widget);
			}
		});
		return link;
	}

	protected boolean useProjectSettings() {
		return isProjectPreferencePage() && fUseProjectSettings != null && fUseProjectSettings.isSelected();
	}

	protected boolean isProjectPreferencePage() {
		return fProject != null;
	}

	protected IProject getProject() {
		return fProject;
	}

	/**
	 * Handle link activation.
	 *
	 * @param link the link
	 */
	final void doLinkActivated(Link link) {
		Map<String, Object> data= getData();
		if (data == null)
			data= new HashMap<String, Object>();
		data.put(DATA_NO_LINK, Boolean.TRUE);

		if (isProjectPreferencePage()) {
			openWorkspacePreferences(data);
		} else {
			HashSet<IJavaProject> projectsWithSpecifics= new HashSet<IJavaProject>();
			try {
				IJavaProject[] projects= JavaCore.create(ResourcesPlugin.getWorkspace().getRoot()).getJavaProjects();
				for (int i= 0; i < projects.length; i++) {
					IJavaProject curr= projects[i];
					if (hasProjectSpecificOptions(curr.getProject())) {
						projectsWithSpecifics.add(curr);
					}
				}
			} catch (JavaModelException e) {
				// ignore
			}
			ProjectSelectionDialog dialog= new ProjectSelectionDialog(getShell(), projectsWithSpecifics);
			if (dialog.open() == Window.OK) {
				IJavaProject res= (IJavaProject) dialog.getFirstResult();
				openProjectProperties(res.getProject(), data);
			}
		}
	}

	protected final void openWorkspacePreferences(Object data) {
		String id= getPreferencePageID();
		PreferencesUtil.createPreferenceDialogOn(getShell(), id, new String[] { id }, data).open();
	}

	protected final void openProjectProperties(IProject project, Object data) {
		String id= getPropertyPageID();
		if (id != null) {
			PreferencesUtil.createPropertyDialogOn(getShell(), project, id, new String[] { id }, data).open();
		}
	}


	protected void enableProjectSpecificSettings(boolean useProjectSpecificSettings) {
		fUseProjectSettings.setSelection(useProjectSpecificSettings);
		enablePreferenceContent(useProjectSpecificSettings);
		updateLinkVisibility();
		doStatusChanged();
	}

	private void updateLinkVisibility() {
		if (fChangeWorkspaceSettings == null || fChangeWorkspaceSettings.isDisposed()) {
			return;
		}

		if (isProjectPreferencePage()) {
			fChangeWorkspaceSettings.setEnabled(!useProjectSettings());
		}
	}


	protected void setPreferenceContentStatus(IStatus status) {
		fBlockStatus= status;
		doStatusChanged();
	}

	/**
	 * Returns a new status change listener that calls {@link #setPreferenceContentStatus(IStatus)}
	 * when the status has changed
	 * @return The new listener
	 */
	protected IStatusChangeListener getNewStatusChangedListener() {
		return new IStatusChangeListener() {
			public void statusChanged(IStatus status) {
				setPreferenceContentStatus(status);
			}
		};
	}

	protected IStatus getPreferenceContentStatus() {
		return fBlockStatus;
	}

	protected void doStatusChanged() {
		if (!isProjectPreferencePage() || useProjectSettings()) {
			updateStatus(fBlockStatus);
		} else {
			updateStatus(new StatusInfo());
		}
	}

	protected void enablePreferenceContent(boolean enable) {
		if (enable) {
			if (fBlockEnableState != null) {
				fBlockEnableState.restore();
				fBlockEnableState= null;
			}
		} else {
			if (fBlockEnableState == null) {
				fBlockEnableState= ControlEnableState.disable(fConfigurationBlockControl);
			}
		}
	}

	/*
	 * @see org.eclipse.jface.preference.IPreferencePage#performDefaults()
	 */
	@Override
	protected void performDefaults() {
		if (useProjectSettings()) {
			enableProjectSpecificSettings(false);
		}
		super.performDefaults();
	}

	private void updateStatus(IStatus status) {
		setValid(!status.matches(IStatus.ERROR));
		StatusUtil.applyToStatusLine(this, status);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IWorkbenchPreferencePage#init(org.eclipse.ui.IWorkbench)
	 */
	public void init(IWorkbench workbench) {
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IWorkbenchPropertyPage#getElement()
	 */
	public IAdaptable getElement() {
		return fProject;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IWorkbenchPropertyPage#setElement(org.eclipse.core.runtime.IAdaptable)
	 */
	public void setElement(IAdaptable element) {
		fProject= (IProject) element.getAdapter(IResource.class);
	}


	/* (non-Javadoc)
	 * @see org.eclipse.jface.preference.PreferencePage#applyData(java.lang.Object)
	 */
	@SuppressWarnings("unchecked")
	@Override
	public void applyData(Object data) {
		if (data instanceof Map) {
			fData= (Map<String, Object>) data;
		}
		if (fChangeWorkspaceSettings != null) {
			if (!offerLink()) {
				fChangeWorkspaceSettings.dispose();
				fParentComposite.layout(true, true);
			}
		}
 	}

	protected Map<String, Object> getData() {
		return fData;
	}

}
