/*******************************************************************************
 * Copyright (c) 2000, 2020 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Paul Pazderski - Bug 251642: show process termination time
 *******************************************************************************/
package org.eclipse.debug.internal.ui.preferences;


import java.text.DateFormat;
import java.text.ParseException;
import java.util.Arrays;
import java.util.Date;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.model.IDebugElement;
import org.eclipse.debug.core.model.IProcess;
import org.eclipse.debug.internal.ui.IDebugHelpContextIds;
import org.eclipse.debug.internal.ui.SWTFactory;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BidiSegmentEvent;
import org.eclipse.swt.custom.BidiSegmentListener;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.dialogs.PropertyPage;

public class ProcessPropertyPage extends PropertyPage {

	private static Font fHeadingFont = JFaceResources.getFontRegistry().getBold(JFaceResources.DIALOG_FONT);

	/**
	 * Constructor for ProcessPropertyPage
	 */
	public ProcessPropertyPage() {
		super();
	}

	@Override
	protected Control createContents(Composite ancestor) {
		noDefaultAndApplyButton();
		Composite parent = SWTFactory.createComposite(ancestor, ancestor.getFont(), 1, 1, GridData.FILL_BOTH);

		IProcess proc = getProcess();

		// create the process launch time section
		SWTFactory.createLabel(parent, DebugPreferencesMessages.ProcessPropertyPage_0, fHeadingFont, 1);
		Text text = SWTFactory.createText(parent, SWT.READ_ONLY, 1);
		((GridData)text.getLayoutData()).horizontalIndent = 10;
		PlatformUI.getWorkbench().getHelpSystem().setHelp(text, IDebugHelpContextIds.PROCESS_PAGE_RUN_AT);
		text.setText(getLaunchTimeText(proc));
		text.setBackground(parent.getBackground());
		SWTFactory.createVerticalSpacer(parent, 2);

		// create the process terminate time section
		SWTFactory.createLabel(parent, DebugPreferencesMessages.ProcessPropertyPage_10, fHeadingFont, 1);
		text = SWTFactory.createText(parent, SWT.READ_ONLY, 1);
		((GridData) text.getLayoutData()).horizontalIndent = 10;
		PlatformUI.getWorkbench().getHelpSystem().setHelp(text, IDebugHelpContextIds.PROCESS_PAGE_TERMINATE_AT);
		text.setText(getTerminateTimeText(proc));
		text.setBackground(parent.getBackground());
		SWTFactory.createVerticalSpacer(parent, 2);

	//create the path name section
		SWTFactory.createLabel(parent, DebugPreferencesMessages.ProcessPropertyPage_1, fHeadingFont, 1);
		text = SWTFactory.createText(parent, SWT.WRAP | SWT.READ_ONLY, 1);
		((GridData)text.getLayoutData()).horizontalIndent = 10;
		text.setText(getPathText(proc));
		text.setBackground(parent.getBackground());
		SWTFactory.createVerticalSpacer(parent, 2);

	//create working directory section
		SWTFactory.createLabel(parent, DebugPreferencesMessages.ProcessPropertyPage_6, fHeadingFont, 1);
		text = SWTFactory.createText(parent, SWT.WRAP | SWT.READ_ONLY, 1);
		((GridData)text.getLayoutData()).horizontalIndent = 10;
		text.setText(getWorkingDirectory(proc));
		text.setBackground(parent.getBackground());
		SWTFactory.createVerticalSpacer(parent, 2);

	//create command line section
		SWTFactory.createLabel(parent, DebugPreferencesMessages.ProcessPropertyPage_Command_Line__1, fHeadingFont, 1);
		StyledText styledText = SWTFactory.createStyledText(parent,
				SWT.WRAP | SWT.READ_ONLY | SWT.BORDER | SWT.V_SCROLL,
				1,
				convertWidthInCharsToPixels(13),
				convertHeightInCharsToPixels(10),
				GridData.FILL_BOTH);
		styledText.setBackground(parent.getBackground());
		((GridData)styledText.getLayoutData()).horizontalIndent = 10;
		String commandLineText = DebugPreferencesMessages.ProcessPropertyPage_5;
		if (proc != null) {
			commandLineText = proc.getAttribute(IProcess.ATTR_CMDLINE);
			String[] arguments = DebugPlugin.parseArguments(commandLineText);
			int count = arguments.length;
			if (count > 1) {
				// render as one argument per line, but don't copy line delimiters to clipboard:
				final int[] segments = new int[count - 1];
				commandLineText = DebugPlugin.renderArguments(arguments, segments);

				styledText.addBidiSegmentListener(new BidiSegmentListener() {
					@Override
					public void lineGetSegments(BidiSegmentEvent event) {
						int offset = event.lineOffset;
						int end = offset + event.lineText.length();

						// extract segments for the current line:
						int iStart = Arrays.binarySearch(segments, offset);
						if (iStart < 0) {
							iStart = -iStart - 1;
						}
						int i = iStart;
						while (i < segments.length && segments[i] < end) {
							i++;
						}
						int n = i - iStart;
						if (n > 0) {
							if (n == segments.length) {
								event.segments = segments;
							} else {
								int[] lineSegments = new int[n];
								System.arraycopy(segments, iStart, lineSegments, 0, n);
								event.segments = lineSegments;
							}
							final char[] chars = new char[n];
							Arrays.fill(chars, '\n');
							event.segmentsChars = chars;
						}
					}
				});
			}
		}
		if(commandLineText != null) {
			styledText.setText(commandLineText);
		}

	//create environment section
		SWTFactory.createLabel(parent, DebugPreferencesMessages.ProcessPropertyPage_7, fHeadingFont, 1);
		text = SWTFactory.createText(parent,
				SWT.H_SCROLL | SWT.READ_ONLY | SWT.BORDER | SWT.V_SCROLL,
				1,
				convertWidthInCharsToPixels(13),
				convertHeightInCharsToPixels(8),
				GridData.FILL_BOTH);
		text.setBackground(parent.getBackground());
		((GridData)text.getLayoutData()).horizontalIndent = 10;
		text.setText(getEnvironment(proc));

		setTitle(DebugPreferencesMessages.ProcessPropertyPage_2);
		return parent;
	}

	/**
	 * Gets the process from the selected element
	 * @return the process or null if the element is not a process
	 *
	 * @since 3.2
	 */
	private IProcess getProcess() {
		IProcess proc = null;
		Object obj = getElement();
		if (obj instanceof IDebugElement) {
			obj = ((IDebugElement)obj).getDebugTarget().getProcess();
		}
		if (obj instanceof IProcess) {
			proc = ((IProcess)obj);
		}
		return proc;
	}

	/**
	 * returns the path text
	 * @param proc the process to extract the path text from
	 * @return the path text or a message indicating no path text available
	 *
	 * @see DebugPlugin#ATTR_PATH
	 * @since 3.2
	 */
	private String getPathText(IProcess proc) {
		String text = DebugPreferencesMessages.ProcessPropertyPage_3;
		if(proc != null) {
			String tmp = proc.getAttribute(DebugPlugin.ATTR_PATH);
			if(tmp != null) {
				return tmp;
			}
			tmp = proc.getLabel();
			// TODO remove this ugly workaround after removing start time from process label
			// in jdt
			int idx = tmp.lastIndexOf('(');
			if(idx < 0) {
				idx = tmp.length();
			}
			text = tmp.substring(0, idx);
		}
		return text;
	}

	/**
	 * Try to get the launch time for the process.
	 *
	 * @param proc the process to get launch time for
	 * @return the launch time or default replacement
	 * @since 3.2
	 */
	private String getLaunchTimeText(IProcess proc) {
		String text = getTimeFromAttribute(proc, DebugPlugin.ATTR_LAUNCH_TIMESTAMP);
		if (text != null) {
			return text;
		}
		// TODO remove this parsing when launch time is no fixed part of label anymore
		Pattern pattern = Pattern.compile("\\(.*\\)"); //$NON-NLS-1$
		Matcher matcher = pattern.matcher(proc.getLabel());
		if (matcher.find()) {
			text = matcher.group(0);
		}
		if (text != null) {
			return text;
		}
		return DebugPreferencesMessages.ProcessPropertyPage_4;
	}

	/**
	 * Try to get the terminate time for the process.
	 *
	 * @param proc the process to get terminate time for
	 * @return the terminate time or default replacement
	 */
	private String getTerminateTimeText(IProcess proc) {
		String text = getTimeFromAttribute(proc, DebugPlugin.ATTR_TERMINATE_TIMESTAMP);
		return text != null ? text : DebugPreferencesMessages.ProcessPropertyPage_4;
	}

	/**
	 * Try to process launch timestamp attribute.
	 *
	 * @param proc the process to check
	 * @param attr the process attribute to check for timestamp
	 * @return the timestamp string or <code>null</code>
	 * @since 3.2
	 */
	private String getTimeFromAttribute(IProcess proc, String attr) {
		if (proc == null || attr == null) {
			return null;
		}
		String time = proc.getAttribute(attr);
		if (time == null) {
			return null;
		}
		// check to see if the date/time is just the raw long (as a string)
		try {
			long l = Long.parseLong(time);
			return DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM).format(new Date(l));
		} catch (NumberFormatException nfe) {
			// not a number try to format the string so it always looks the same
			try {
				Date fdate = DateFormat.getInstance().parse(time);
				return DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM).format(fdate);
			} catch (ParseException pe) {
				// couldn't do it, return the raw string
			}
		}
		return time;
	}

	/**
	 * Initializes the text to be displayed in the environment text widget
	 * @param proc
	 * @return the environment path or a default string never <code>null</code>
	 *
	 * @see DebugPlugin#ATTR_ENVIRONMENT
	 * @since 3.8
	 */
	String getEnvironment(IProcess proc) {
		String env = DebugPreferencesMessages.ProcessPropertyPage_8;
		if(proc != null) {
			String tmp = proc.getAttribute(DebugPlugin.ATTR_ENVIRONMENT);
			if(tmp != null) {
				return tmp;
			}
		}
		return env;
	}

	/**
	 * Initializes the text to be displayed in the working directory text widget
	 *
	 * @param proc
	 * @return the text to display or a default {@link String} never <code>null</code>
	 *
	 * @see DebugPlugin#ATTR_WORKING_DIRECTORY
	 * @since 3.8
	 */
	String getWorkingDirectory(IProcess proc) {
		String wd = DebugPreferencesMessages.ProcessPropertyPage_9;
		if(proc != null) {
			String tmp = proc.getAttribute(DebugPlugin.ATTR_WORKING_DIRECTORY);
			if(tmp != null) {
				return tmp;
			}
		}
		return wd;
	}

	@Override
	public void createControl(Composite parent) {
		super.createControl(parent);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(getControl(),	IDebugHelpContextIds.PROCESS_PROPERTY_PAGE);
	}
}