/*******************************************************************************
 * Copyright (c) 2000, 2018 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
 *
 *******************************************************************************/
package org.eclipse.dltk.internal.debug.ui.log;

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

import org.eclipse.dltk.ui.DLTKUIPlugin;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.IToolBarManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.TextViewer;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.SashForm;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.ui.IWorkbenchActionConstants;
import org.eclipse.ui.contexts.IContextActivation;
import org.eclipse.ui.contexts.IContextService;
import org.eclipse.ui.part.ViewPart;

public class ScriptDebugLogView extends ViewPart {
	public static final String VIEW_ID = "org.eclipse.dltk.debug.ui.dbgpLogView"; //$NON-NLS-1$
	public static final String THEME_ID = "org.eclipse.dltk.debug.ui.dbgpLogView.txtViewFont"; //$NON-NLS-1$

	private final List<ScriptDebugLogItem> items = new ArrayList<>();
	private TableViewer viewer;
	private TextViewer textViewer;
	private IDocument textDocument;
	private IPropertyChangeListener fontRegistryChangeListener;
	private IContextActivation fContextActivation;

	public ScriptDebugLogView() {
		super();
	}

	@Override
	public void setFocus() {
		viewer.getControl().setFocus();
	}

	@Override
	public void createPartControl(Composite parent) {
		final SashForm sashForm = new SashForm(parent, SWT.HORIZONTAL);
		viewer = new TableViewer(sashForm, SWT.H_SCROLL | SWT.V_SCROLL
				| SWT.MULTI | SWT.FULL_SELECTION | SWT.VIRTUAL);
		viewer.getTable().setHeaderVisible(true);
		viewer.getTable().setLinesVisible(true);
		addColumn(Messages.Column_Date, 100, true);
		addColumn(Messages.Column_Time, 100, true);
		addColumn(Messages.Column_Type, 80, true);
		addColumn(Messages.Column_Session, 80, true);
		addColumn(Messages.Column_Message, 400, false);
		viewer.getTable().addListener(SWT.Resize, event -> {
			final Table table = (Table) event.widget;
			final int columnCount = table.getColumnCount();
			int w = table.getClientArea().width;
			for (int i = 0; i < columnCount - 1; ++i) {
				w -= table.getColumn(i).getWidth();
			}
			if (w > 0) {
				table.getColumn(columnCount - 1).setWidth(w);
			}
		});
		viewer.addSelectionChangedListener(event -> {
			if (event.getSelection() instanceof IStructuredSelection) {
				final Object first = event.getStructuredSelection()
						.getFirstElement();
				if (first instanceof ScriptDebugLogItem) {
					textDocument.set(((ScriptDebugLogItem) first).getMessage());
					return;
				}
			}
			textDocument.set(""); //$NON-NLS-1$
		});
		viewer.setContentProvider(new ScriptDebugLogContentProvider());
		viewer.setLabelProvider(new ScriptDebugLogLabelProvider());
		viewer.setInput(items);
		textDocument = new Document();
		textViewer = new TextViewer(sashForm,
				SWT.V_SCROLL | SWT.H_SCROLL | SWT.WRAP | SWT.READ_ONLY);
		textViewer.setDocument(textDocument);
		fontRegistryChangeListener = event -> handlePropertyChangeEvent(event);
		JFaceResources.getFontRegistry()
				.addListener(fontRegistryChangeListener);

		updateFont();
		sashForm.setWeights(new int[] { 75, 25 });
		createActions();
		createMenu();
		createToolbar();
		createContextMenu();
		IContextService ctxService = getSite()
				.getService(IContextService.class);
		if (ctxService != null) {
			fContextActivation = ctxService
					.activateContext(DLTKUIPlugin.CONTEXT_VIEWS);
		}
	}

	@Override
	public void dispose() {
		if (fContextActivation != null) {
			IContextService ctxService = getSite()
					.getService(IContextService.class);
			if (ctxService != null) {
				ctxService.deactivateContext(fContextActivation);
			}
		}
		if (fontRegistryChangeListener != null) {
			JFaceResources.getFontRegistry()
					.removeListener(fontRegistryChangeListener);
			fontRegistryChangeListener = null;
		}
		super.dispose();
	}

	/**
	 * @param event
	 */
	protected void handlePropertyChangeEvent(PropertyChangeEvent event) {
		final String key = event.getProperty();
		if (key.equals(THEME_ID)) {
			updateFont();
		}
	}

	private void updateFont() {
		textViewer.getTextWidget().setFont(JFaceResources.getFont(THEME_ID));
	}

	/**
	 * @param caption
	 * @param width
	 */
	private void addColumn(String caption, int width, boolean center) {
		final TableColumn column = new TableColumn(viewer.getTable(), SWT.LEFT);
		column.setText(caption);
		column.setWidth(width);
	}

	public void append(final ScriptDebugLogItem item) {
		synchronized (items) {
			items.add(item);
		}
		final Table table = viewer.getTable();
		if (table.isDisposed())
			return;
		final Display display = table.getDisplay();
		if (display.isDisposed())
			return;
		display.asyncExec(() -> {
			viewer.refresh(false, false);
			if (table.isDisposed() || table.getDisplay().isDisposed())
				return;
			final int itemCount = table.getItemCount();
			if (itemCount > 0) {
				table.showItem(table.getItem(itemCount - 1));
			}
		});
	}

	private IAction copyAction;
	private IAction clearAction;

	public void createActions() {
		copyAction = new ScriptDebugLogCopyAction(viewer);
		clearAction = new Action(Messages.ScriptDebugLogView_clear) {
			@Override
			public void run() {
				synchronized (items) {
					items.clear();
				}
				viewer.refresh();
			}
		};
	}

	private void createMenu() {
		IMenuManager manager = getViewSite().getActionBars().getMenuManager();
		manager.add(copyAction);
		manager.add(clearAction);
	}

	private void createToolbar() {
		IToolBarManager manager = getViewSite().getActionBars()
				.getToolBarManager();
		manager.add(copyAction);
		manager.add(clearAction);
	}

	private void createContextMenu() {
		// Create menu manager.
		MenuManager menuManager = new MenuManager();
		menuManager.setRemoveAllWhenShown(true);
		menuManager.addMenuListener(manager -> fillContextMenu(manager));

		// Create menu.
		Menu menu = menuManager.createContextMenu(viewer.getControl());
		viewer.getControl().setMenu(menu);

		// Register menu for extension.
		getSite().registerContextMenu(menuManager, viewer);
	}

	private void fillContextMenu(IMenuManager manager) {
		manager.add(copyAction);
		manager.add(clearAction);
		manager.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS));
	}

}