/*******************************************************************************
 * Copyright (c) 2000, 2005 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.debug.ui.launcher;

import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILaunchConfiguration;
import org.eclipse.debug.core.ILaunchConfigurationType;
import org.eclipse.debug.core.ILaunchConfigurationWorkingCopy;
import org.eclipse.debug.core.ILaunchManager;
import org.eclipse.debug.ui.DebugUITools;
import org.eclipse.debug.ui.IDebugModelPresentation;
import org.eclipse.debug.ui.ILaunchShortcut;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.debug.ui.launchConfigurations.AppletParametersTab;
import org.eclipse.jdt.internal.debug.ui.JDIDebugUIPlugin;
import org.eclipse.jdt.launching.IJavaLaunchConfigurationConstants;
import org.eclipse.jdt.ui.JavaElementLabelProvider;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.dialogs.ElementListSelectionDialog;

public class JavaAppletLaunchShortcut implements ILaunchShortcut {

	private static final String EMPTY_STRING = ""; //$NON-NLS-1$

	protected void searchAndLaunch(Object[] search, String mode) {
		IType[] types= null;

		if (search != null) {
			try {
				types = AppletLaunchConfigurationUtils.findApplets(new WorkspaceOperationRunner(), search);
			} catch (InterruptedException e) {
				JDIDebugUIPlugin.log(e);
				return;
			} catch (InvocationTargetException e) {
				JDIDebugUIPlugin.log(e);
				return;
			}
			IType type = null;
			if (types.length == 0) {
				MessageDialog.openInformation(getShell(), LauncherMessages.appletlauncher_search_dialog_title, LauncherMessages.appletlauncher_search_dialog_error_noapplets);   // 
			} else if (types.length > 1) {
				type = chooseType(types, mode);
			} else {
				type = types[0];
			}
			if (type != null) {
				launch(type, mode);
			}
		}
	}
	
	/**
	 * @see ILaunchShortcut#launch(IEditorPart, String)
	 */
	public void launch(IEditorPart editor, String mode) {
		IEditorInput input = editor.getEditorInput();
		IJavaElement javaElement = (IJavaElement) input.getAdapter(IJavaElement.class);
		if (javaElement != null) {
			searchAndLaunch(new Object[] {javaElement}, mode);
		} else {
			MessageDialog.openInformation(getShell(), LauncherMessages.appletlauncher_search_dialog_title, LauncherMessages.appletlauncher_search_dialog_error_noapplets);   // 
		}
	}

	/**
	 * @see ILaunchShortcut#launch(ISelection, String)
	 */
	public void launch(ISelection selection, String mode) {
		if (selection instanceof IStructuredSelection) {
			searchAndLaunch(((IStructuredSelection)selection).toArray(), mode);
		} 
	}
	
	/**
	 * Prompts the user to select a type
	 * 
	 * @return the selected type or <code>null</code> if none.
	 */
	protected IType chooseType(IType[] types, String mode) {
		ElementListSelectionDialog dialog= new ElementListSelectionDialog(getShell(), new JavaElementLabelProvider());
		dialog.setElements(types);
		dialog.setTitle(LauncherMessages.appletlauncher_selection_type_dialog_title); 
		if (mode.equals(ILaunchManager.DEBUG_MODE)) {
			dialog.setMessage(LauncherMessages.appletlauncher_selection_type_dialog_message_debug);   
		} else {
			dialog.setMessage(LauncherMessages.appletlauncher_selection_type_dialog_message_run);  
		}
		dialog.setMultipleSelection(false);
		if (dialog.open() == Window.OK) {
			return (IType)dialog.getFirstResult();
		}
		return null;
	}
	
	/**
	 * Launches a configuration for the given type
	 */
	protected void launch(IType type, String mode) {
		ILaunchConfiguration config = findLaunchConfiguration(type, mode);
		if (config != null) {
			DebugUITools.launch(config, mode);
		}			
	}
	
	/**
	 * Locate a configuration to relaunch for the given type.  If one cannot be found, create one.
	 * 
	 * @return a re-useable config or <code>null</code> if none
	 */
	protected ILaunchConfiguration findLaunchConfiguration(IType type, String mode) {
		ILaunchConfigurationType configType= getAppletLaunchConfigType();
		List candidateConfigs= Collections.EMPTY_LIST;
		try {
			ILaunchConfiguration[] configs= DebugPlugin.getDefault().getLaunchManager().getLaunchConfigurations(configType);
			candidateConfigs= new ArrayList(configs.length);
			for (int i= 0; i < configs.length; i++) {
				ILaunchConfiguration config= configs[i];
				if (config.getAttribute(IJavaLaunchConfigurationConstants.ATTR_MAIN_TYPE_NAME, "").equals(type.getFullyQualifiedName())) {  //$NON-NLS-1$
					if (config.getAttribute(IJavaLaunchConfigurationConstants.ATTR_PROJECT_NAME, "").equals(type.getJavaProject().getElementName())) {  //$NON-NLS-1$
						candidateConfigs.add(config);
					}
				}
			}
		} catch (CoreException e) {
			JDIDebugUIPlugin.log(e);
		}
		
		// If there are no existing configs associated with the IType, create one.
		// If there is exactly one config associated with the IType, return it.
		// Otherwise, if there is more than one config associated with the IType, prompt the
		// user to choose one.
		int candidateCount= candidateConfigs.size();
		if (candidateCount < 1) {
			return createConfiguration(type);
		} else if (candidateCount == 1) {
			return (ILaunchConfiguration) candidateConfigs.get(0);
		} else {
			// Prompt the user to choose a config.  A null result means the user
			// cancelled the dialog, in which case this method returns null,
			// since cancelling the dialog should also cancel launching anything.
			ILaunchConfiguration config= chooseConfiguration(candidateConfigs, mode);
			if (config != null) {
				return config;
			}
		}
		return null;
	}
	
	/**
	 * Create & return a new configuration based on the specified <code>IType</code>.
	 */
	protected ILaunchConfiguration createConfiguration(IType type) {
		ILaunchConfiguration config = null;
		try {
			ILaunchConfigurationType configType = getAppletLaunchConfigType();
			ILaunchConfigurationWorkingCopy wc = configType.newInstance(null, DebugPlugin.getDefault().getLaunchManager().generateUniqueLaunchConfigurationNameFrom(type.getElementName())); 
			wc.setAttribute(IJavaLaunchConfigurationConstants.ATTR_MAIN_TYPE_NAME, type.getFullyQualifiedName());
			wc.setAttribute(IJavaLaunchConfigurationConstants.ATTR_PROJECT_NAME, type.getJavaProject().getElementName());
			wc.setAttribute(IJavaLaunchConfigurationConstants.ATTR_APPLET_WIDTH, AppletParametersTab.DEFAULT_APPLET_WIDTH);
			wc.setAttribute(IJavaLaunchConfigurationConstants.ATTR_APPLET_HEIGHT, AppletParametersTab.DEFAULT_APPLET_HEIGHT);
			wc.setAttribute(IJavaLaunchConfigurationConstants.ATTR_APPLET_NAME, EMPTY_STRING);
			config = wc.doSave();		
		} catch (CoreException ce) {
			JDIDebugUIPlugin.log(ce);			
		}
		return config;
	}
		
	/**
	 * Show a selection dialog that allows the user to choose one of the specified
	 * launch configurations.  Return the chosen config, or <code>null</code> if the
	 * user cancelled the dialog.
	 */
	protected ILaunchConfiguration chooseConfiguration(List configList, String mode) {
		IDebugModelPresentation labelProvider = DebugUITools.newDebugModelPresentation();
		ElementListSelectionDialog dialog= new ElementListSelectionDialog(getShell(), labelProvider);
		dialog.setElements(configList.toArray());
		dialog.setTitle(LauncherMessages.appletlauncher_selection_configuration_dialog_title);  
		if (mode.equals(ILaunchManager.DEBUG_MODE)) {
			dialog.setMessage(LauncherMessages.appletlauncher_selection_configuration_dialog_message_debug);  
		} else {
			dialog.setMessage(LauncherMessages.appletlauncher_selection_configuration_dialog_message_run);  
		}
		dialog.setMultipleSelection(false);
		int result= dialog.open();
		labelProvider.dispose();
		if (result == Window.OK) {
			return (ILaunchConfiguration)dialog.getFirstResult();
		}
		return null;		
	}
	
	/**
	 * Returns the local java launch config type
	 */
	protected ILaunchConfigurationType getAppletLaunchConfigType() {
		ILaunchManager lm= DebugPlugin.getDefault().getLaunchManager();
		return lm.getLaunchConfigurationType(IJavaLaunchConfigurationConstants.ID_JAVA_APPLET);		
	}	
	
	/**
	 * Convenience method to get the window that owns this action's Shell.
	 */
	protected Shell getShell() {
		return JDIDebugUIPlugin.getActiveWorkbenchShell();
	}
	
	/**
	 * Determines and returns the selection that provides context for the launch,
	 * or <code>null</code> if there is no selection.
	 */
	protected IStructuredSelection resolveSelection(IWorkbenchWindow window) {
		if (window == null) {
			return null;
		}
		ISelection selection= window.getSelectionService().getSelection();
		if (selection == null || selection.isEmpty() || !(selection instanceof IStructuredSelection)) {
			// there is no obvious selection - go fishing
			selection = null;
			IWorkbenchPage page = window.getActivePage();
			if (page == null) {
				//workspace is closed
				return null;
			}

			// first, see if there is an active editor, and try its input element
			IEditorPart editor= page.getActiveEditor();
			Object element = null;
			if (editor != null) {
				element = editor.getEditorInput();
			}

			if (selection == null && element != null) {
				selection = new StructuredSelection(element);
			}
		}
		return (IStructuredSelection)selection;
	}

}