/*******************************************************************************
 * Copyright (c) 2007, 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
 *******************************************************************************/
package org.eclipse.jdt.internal.debug.ui.jres;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.List;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.internal.ui.SWTFactory;
import org.eclipse.debug.ui.StringVariableSelectionDialog;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.debug.ui.launchConfigurations.AbstractVMInstallPage;
import org.eclipse.jdt.internal.debug.ui.IJavaDebugHelpContextIds;
import org.eclipse.jdt.internal.debug.ui.JavaDebugImages;
import org.eclipse.jdt.internal.debug.ui.StatusInfo;
import org.eclipse.jdt.internal.launching.StandardVMType;
import org.eclipse.jdt.launching.AbstractVMInstallType;
import org.eclipse.jdt.launching.IVMInstallType;
import org.eclipse.jdt.launching.VMStandin;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.DirectoryDialog;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.PlatformUI;

/**
 * Page used to edit a standard VM.
 *
 * @since 3.3
 */
public class StandardVMPage extends AbstractVMInstallPage {

	// VM being edited or created
	private VMStandin fVM;
	private Text fVMName;
	private Text fVMArgs;
	private Text fJRERoot;
	private VMLibraryBlock fLibraryBlock;
// the VM install's javadoc location
	private URL fJavadocLocation = null;
	private boolean fAutoDetectAttributes = false;
	private IStatus[] fFieldStatus = new IStatus[1];

	/**
	 *
	 */
	public StandardVMPage() {
		super(JREMessages.StandardVMPage_0);
		for (int i = 0; i < fFieldStatus.length; i++) {
			fFieldStatus[i] = Status.OK_STATUS;
		}
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.dialogs.IDialogPage#getImage()
	 */
	@Override
	public Image getImage() {
		return JavaDebugImages.get(JavaDebugImages.IMG_WIZBAN_LIBRARY);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.dialogs.IDialogPage#createControl(org.eclipse.swt.widgets.Composite)
	 */
	@Override
	public void createControl(Composite p) {
		// create a composite with standard margins and spacing
		Composite composite = new Composite(p, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.numColumns = 3;
		composite.setLayout(layout);
		composite.setLayoutData(new GridData(GridData.FILL_BOTH));

	// VM location
		SWTFactory.createLabel(composite, JREMessages.addVMDialog_jreHome, 1);
		fJRERoot = SWTFactory.createSingleText(composite, 1);
		Button folders = SWTFactory.createPushButton(composite, JREMessages.AddVMDialog_22, null);
		GridData data = (GridData) folders.getLayoutData();
		data.horizontalAlignment = GridData.END;
	//VM name
		SWTFactory.createLabel(composite, JREMessages.addVMDialog_jreName, 1);
		fVMName = SWTFactory.createSingleText(composite, 2);
	//VM arguments
		SWTFactory.createLabel(composite, JREMessages.AddVMDialog_23, 1);
		fVMArgs = SWTFactory.createSingleText(composite, 1);
		Button variables = SWTFactory.createPushButton(composite, JREMessages.StandardVMPage_3, null);
		data = (GridData) variables.getLayoutData();
		data.horizontalAlignment = GridData.END;
	//VM libraries block
		SWTFactory.createLabel(composite, JREMessages.AddVMDialog_JRE_system_libraries__1, 3);
		fLibraryBlock = new VMLibraryBlock();
		fLibraryBlock.setWizard(getWizard());
		fLibraryBlock.createControl(composite);
		Control libControl = fLibraryBlock.getControl();
		GridData gd = new GridData(GridData.FILL_BOTH);
		gd.horizontalSpan = 3;
		libControl.setLayoutData(gd);


	//add the listeners now to prevent them from monkeying with initialized settings
		fVMName.addModifyListener(new ModifyListener() {
			@Override
			public void modifyText(ModifyEvent e) {
				validateVMName(false);
			}
		});
		fJRERoot.addModifyListener(new ModifyListener() {
			@Override
			public void modifyText(ModifyEvent e) {
				validateJRELocation(false);
			}
		});
		folders.addSelectionListener(new SelectionListener() {
			@Override
			public void widgetDefaultSelected(SelectionEvent e) {}
			@Override
			public void widgetSelected(SelectionEvent e) {
				DirectoryDialog dialog = new DirectoryDialog(getShell(), SWT.SHEET);
				File file = new File(fJRERoot.getText());
				String text = fJRERoot.getText();
				if (file.isFile()) {
					text = file.getParentFile().getAbsolutePath();
				}
				dialog.setFilterPath(text);
				dialog.setMessage(JREMessages.addVMDialog_pickJRERootDialog_message);
				String newPath = dialog.open();
				if (newPath != null) {
					fJRERoot.setText(newPath);
				}
			}
		});
		variables.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				StringVariableSelectionDialog dialog = new StringVariableSelectionDialog(getShell());
				if (dialog.open() == Window.OK) {
					String expression = dialog.getVariableExpression();
					if (expression != null) {
						fVMArgs.insert(expression);
					}
				}
			}
		});
		Dialog.applyDialogFont(composite);
		setControl(composite);
		initializeFields();
		PlatformUI.getWorkbench().getHelpSystem().setHelp(getControl(), IJavaDebugHelpContextIds.EDIT_JRE_STD_VM_WIZARD_PAGE);
	}

	/**
	 * Validates the JRE location
	 * @param init <code>true</code> if page is getting initialized else <code>false</code>
	 * @return the status after validating the JRE location
	 */
	private void validateJRELocation(boolean init) {
		String locationName = fJRERoot.getText();
		IStatus s = null;
		File file = null;
		if (locationName.length() == 0 && init) {
			return;
		}

		if (locationName.length() == 0) {
			s = new StatusInfo(IStatus.WARNING, JREMessages.addVMDialog_enterLocation);
		}
		else {
			file = new File(locationName);
			if (!file.exists()) {
				s = new StatusInfo(IStatus.ERROR, JREMessages.addVMDialog_locationNotExists);
			}
			else {
				final IStatus[] temp = new IStatus[1];
				final File tempFile = file;
				Runnable r = new Runnable() {
					@Override
					public void run() {
						temp[0] = fVM.getVMInstallType().validateInstallLocation(tempFile);
					}
				};
				BusyIndicator.showWhile(getShell().getDisplay(), r);
				s = temp[0];
			}
		}
		if (file != null) {
			fVM.setInstallLocation(file);
		}
		if (s.isOK() && file != null) {
			String name = fVMName.getText();
			if (name == null || name.trim().length() == 0) {
				// auto-generate VM name
				if (file.isFile()) {
					String fileName = file.getName();
					int index = fileName.lastIndexOf(".ee"); //$NON-NLS-1$
					if (index > 0) {
						fileName = fileName.substring(0, index);
					}
					fVMName.setText(fileName);
				} else {
					try {
						String genName = null;
						IPath path = new Path(file.getCanonicalPath());
						int segs = path.segmentCount();
						if (segs == 1) {
							genName = path.segment(0);
						}
						else if (segs >= 2) {
							String last = path.lastSegment();
							if ("jre".equalsIgnoreCase(last)) { //$NON-NLS-1$
								genName = path.segment(segs - 2);
							}
							else {
								genName = last;
							}
						}
						if (genName != null) {
							fVMName.setText(genName);
						}
					} catch (IOException e) {}
				}
			}
		}
		detectJavadocLocation();
		if (s.isOK()) {
			List<String> allVersions = JavaCore.getAllVersions();
			String latest = allVersions.get(allVersions.size() - 1);
			IVMInstallType vmType = fVM.getVMInstallType();
			if (vmType instanceof StandardVMType) {
				String vmver = ((StandardVMType) vmType).readReleaseVersion(getInstallLocation());
				if (vmver != null && vmver.length() != 0 && JavaCore.compareJavaVersions(vmver, latest) > 0) {
					s = new StatusInfo(IStatus.INFO, JREMessages.JREsPreferencePage_9);
				}
			}
		}
		setJRELocationStatus(s);
		fLibraryBlock.setSelection(fVM);
		updatePageStatus();
	}

	/**
	 * Auto-detects the default javadoc location
	 */
	private void detectJavadocLocation() {
		if (fAutoDetectAttributes) {
			IVMInstallType type = fVM.getVMInstallType();
			if (type instanceof AbstractVMInstallType) {
				AbstractVMInstallType atype = (AbstractVMInstallType)type;
				fJavadocLocation = atype.getDefaultJavadocLocation(getInstallLocation());
				String args = atype.getDefaultVMArguments(getInstallLocation());
				if (args != null) {
					fVMArgs.setText(args);
				}
			}
		} else {
			fJavadocLocation = fVM.getJavadocLocation();
		}
	}

	/**
	 * Returns the installation location as a file from the JRE root text control
	 * @return the installation location as a file
	 */
	protected File getInstallLocation() {
		return new File(fJRERoot.getText());
	}

	/**
	 * Validates the entered name of the VM
	 * @param init <code>true</code> if page is getting initialized else <code>false</code>
	 * @return the status of the name validation
	 */
	private void validateVMName(boolean init) {
		nameChanged(fVMName.getText(), init);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jdt.debug.ui.launchConfigurations.AbstractVMInstallPage#finish()
	 */
	@Override
	public boolean finish() {
		setFieldValuesToVM(fVM);
		fLibraryBlock.finish();
		return true;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jdt.debug.ui.launchConfigurations.AbstractVMInstallPage#getSelection()
	 */
	@Override
	public VMStandin getSelection() {
		return fVM;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jdt.debug.ui.launchConfigurations.AbstractVMInstallPage#setSelection(org.eclipse.jdt.launching.VMStandin)
	 */
	@Override
	public void setSelection(VMStandin vm) {
		super.setSelection(vm);
		fVM = vm;
		fAutoDetectAttributes = vm.getJavadocLocation() == null;
		setTitle(JREMessages.StandardVMPage_1);
		setDescription(JREMessages.StandardVMPage_2);
	}

	/**
	 * initialize fields to the specified VM
	 * @param vm the VM to initialize from
	 */
	protected void setFieldValuesToVM(VMStandin vm) {
		File dir = new File(fJRERoot.getText());
		File file = dir.getAbsoluteFile();
		vm.setInstallLocation(file);
		vm.setName(fVMName.getText());
		vm.setJavadocLocation(getURL());

		String argString = fVMArgs.getText().trim();
		if (argString != null && argString.length() > 0) {
			vm.setVMArgs(argString);
		}
		else {
			vm.setVMArgs(null);
		}
	}

	/**
	 * Returns the URL for the javadoc location
	 * @return the URL for the javadoc location
	 */
	protected URL getURL() {
		return fJavadocLocation;
	}

	/**
	 * Creates a unique name for the VMInstallType
	 * @param vmType the vm install type
	 * @return a unique name
	 */
	protected static String createUniqueId(IVMInstallType vmType) {
		String id = null;
		do {
			id = String.valueOf(System.currentTimeMillis());
		} while (vmType.findVMInstall(id) != null);
		return id;
	}

	/**
	 * Initialize the dialogs fields
	 */
	private void initializeFields() {
		fLibraryBlock.setSelection(fVM);
		if (fVMName.getText() != null && fVMName.getText().length() == 0) {
			if (fVM.getName().length() != 0) {
				fVMName.setText(fVM.getName());
			}
		} else {
			fVMName.setText(fVM.getName());
		}
		File installLocation = fVM.getInstallLocation();
		if (installLocation != null) {
			fJRERoot.setText(installLocation.getAbsolutePath());
		}
		String vmArgs = fVM.getVMArgs();
		if (vmArgs != null) {
			fVMArgs.setText(vmArgs);
		}
		validateVMName(true);
		validateJRELocation(true);
	}

	/**
	 * Sets the status of the JRE location field.
	 *
	 * @param status JRE location status
	 */
	private void setJRELocationStatus(IStatus status) {
		fFieldStatus[0] = status;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.dialogs.DialogPage#getErrorMessage()
	 */
	@Override
	public String getErrorMessage() {
		String message = super.getErrorMessage();
		if (message == null) {
			return fLibraryBlock.getErrorMessage();
		}
		return message;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.wizard.WizardPage#isPageComplete()
	 */
	@Override
	public boolean isPageComplete() {
		boolean complete = super.isPageComplete();
		if (complete) {
			return fLibraryBlock.isPageComplete();
		}
		return complete;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jdt.debug.ui.launchConfigurations.AbstractVMInstallPage#getVMStatus()
	 */
	@Override
	protected IStatus[] getVMStatus() {
		return fFieldStatus;
	}

}