org.eclipse.mylyn.monitor.reports/src/org/eclipse/mylyn/monitor/reports/ui/actions/SwitchTaskDataFolderAction.java

package org.eclipse.mylar.monitor.reports.ui.actions;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.mylar.core.MylarPlugin;
import org.eclipse.mylar.monitor.reports.MylarReportsPlugin;
import org.eclipse.mylar.monitor.reports.ui.views.ComboSelectionDialog;
import org.eclipse.mylar.tasklist.MylarTasklistPlugin;
import org.eclipse.mylar.tasklist.ui.views.TaskListView;
import org.eclipse.mylar.ui.actions.ToggleContextCaptureAction;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IViewActionDelegate;
import org.eclipse.ui.IViewPart;

/**
 * Contributes a menu item to the task list that opens a dialog box
 * that allows the user to select a task data directory to use.
 * 
 * @author Wesley Coelho
 */
public class SwitchTaskDataFolderAction extends Action implements IViewActionDelegate {

	protected final static String TITLE = "Switch Task Data Folder";
	protected final static String PROMPT = "Select the folder to switch to:";
	protected final static String MAIN_LOCAL_DATA_DIR = "Main Task Data Folder";
	protected Shell shell = null;
	
	public void init(IViewPart view) {
		shell = view.getViewSite().getShell();
	}

	public void run(IAction action) {

		String[] folderStrings = getFolderStrings();
		String targetFolder = null;
		if (folderStrings != null){
			targetFolder = showComboSelectionDialog(folderStrings);
		}
		
		if (targetFolder != null && !targetFolder.trim().equals("")){
			switchTaskDataFolder(targetFolder);
		}
	}

	public void selectionChanged(IAction action, ISelection selection) {
		//No action required
	}

	/**
	 * Prompts the user for the name of the task data folder to switch
	 * to. Returns the string selected by the user or the empty string
	 * if no valid input was given.
	 */
	protected String showComboSelectionDialog(String[] folderStrings){
		ComboSelectionDialog dialog = new ComboSelectionDialog(shell, TITLE, PROMPT, folderStrings, 0);
		dialog.open();
		
		return dialog.getSelectedString();
	}
	
	/**
	 * Returns an array of the string names of the folders in the main
	 * data directory plus the default folder.
	 * 
	 * This performs validation and will alert the user of the following
	 * failures:
	 * - No shared task folder specified
	 * - No subfolders with task data
	 * 
	 * Will return null on failure
	 * (Public for testing only)
	 */
	public String[] getFolderStrings(){
		try {
			List<String> folders = new ArrayList<String>();
					
			//Check that a shared data path has been specified
			String sharedDataPath = MylarReportsPlugin.getDefault().getRootSharedDataDirectory();
			if (sharedDataPath.trim().equals("")){
				MessageDialog.openError(shell, "Switch Task Folder Error", "Please specify a root shared task folder in the Mylar Reports preference page.");
				return null;
			}
			
			//Check that the directory is accessible
			File rootDir = new File(sharedDataPath);
			if (!rootDir.exists() || !rootDir.isDirectory()){
				MessageDialog.openError(shell, "Switch Task Folder Error", "The root folder specified in the Mylar Reports preference page could not be found.");
				return null;
			}
			
			//Add the option to switch back to the main local data directory
			if (MylarPlugin.getDefault().isSharedDataDirectoryEnabled()){
				folders.add(MAIN_LOCAL_DATA_DIR);
			}
				
			//Add the list of folders with task data
			File[] files = rootDir.listFiles();
			for (int i = 0; i < files.length; i++) {
				File currFile = files[i];
				if (currFile.isDirectory() && containsTaskData(currFile) && !MylarPlugin.getDefault().getMylarDataDirectory().endsWith(currFile.getName())){
					folders.add(currFile.getName());
				}
			}
			
			//Check that at least one folder was found to switch to
			if (!(folders.size() > 0)){
				MessageDialog.openError(shell, "Switch Task Folder Error", "No task data folders were found in the root folder specified in the Mylar Reports preference page.");
				return null;
			}
			
			String[] folderStrings = new String[folders.size()];
			for(int i = 0; i < folderStrings.length; i++){
				folderStrings[i] = folders.get(i);
			}
			
			return folderStrings;
			
		} catch (RuntimeException e) {
			MylarPlugin.fail(e, "Could not create list of task folders to switch to.", true);
			return null;
		}
	}
	
	/**
	 * Returns true if the specified folder contains task data.
	 * Currently just checks if it contains a task list file.
	 */
	protected boolean containsTaskData(File folder){
		File[] files = folder.listFiles();
		for (int i = 0; i < files.length; i++) {
			File currFile = files[i];
			if (currFile.isFile() && currFile.getName().equals(MylarTasklistPlugin.DEFAULT_TASK_LIST_FILE)){
				return true;
			}
		}		
		
		return false;
	}
	
	/**
	 * Switches the current data folder to the specified folder.
	 * Specify only the folder name and not the full path.
	 * 
	 * Note: This currently always resumes capture when returning
	 * to the main data directory (and suspends capture when
	 * switching to a shared directory).
	 * 
	 * (Public for testing only)
	 */
	public void switchTaskDataFolder(String targetFolder){
		
		MylarTasklistPlugin.getDefault().saveTaskListAndContexts();
		
		if (targetFolder.equals(MAIN_LOCAL_DATA_DIR)){
			MylarPlugin.getDefault().setSharedDataDirectoryEnabled(false);
			MylarTasklistPlugin.getDefault().setDataDirectory(MylarPlugin.getDefault().getMylarDataDirectory());
			(new ToggleContextCaptureAction()).resume(); // TODO: don't use actions directly
			TaskListView.getDefault().indicateSharedFolder("");
			MylarPlugin.getContextManager().setActivationHistorySuppressed(false);
		}
		else{
			String dataDirPath = MylarReportsPlugin.getDefault().getRootSharedDataDirectory() + File.separator + targetFolder;
			MylarPlugin.getDefault().setSharedDataDirectory(dataDirPath);
			MylarPlugin.getDefault().setSharedDataDirectoryEnabled(true);
			MylarTasklistPlugin.getDefault().setDataDirectory(dataDirPath);
			(new ToggleContextCaptureAction()).pause();
			TaskListView.getDefault().indicateSharedFolder(targetFolder);
			MylarPlugin.getContextManager().setActivationHistorySuppressed(true);
		}
	}
	
}