package no.uio.ifi.refaktor.handlers.entrypoints;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.internal.core.JavaProject;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ITreeSelection;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.handlers.HandlerUtil;

import no.uio.ifi.refaktor.change.exceptions.RefaktorChangerException;
import no.uio.ifi.refaktor.debugging.RefaktorDebug;
import no.uio.ifi.refaktor.forTests.Refactorer;

@SuppressWarnings("restriction")
public abstract class RefactorHandler extends AbstractHandler{

	@Override
	public Object execute(ExecutionEvent event) throws ExecutionException {
		long startTime = System.currentTimeMillis();
		ISelection selection = HandlerUtil.getCurrentSelectionChecked(event);
		IWorkbenchWindow window = HandlerUtil.getActiveWorkbenchWindowChecked(event);

		assert selection instanceof ITreeSelection;
		ITreeSelection treeSelection = (ITreeSelection) selection;
		Object o = treeSelection.getFirstElement();
		Refactorer changer;
		if(o instanceof IMethod && supports((IMethod) o)){
			IMethod method = (IMethod) o;
			changer = getChanger(method);
		}
		else if(o instanceof JavaProject && supports(((JavaProject) o).getProject())){
			JavaProject jp = (JavaProject) o;
			IProject project = jp.getProject();
			changer = getChanger(project);
		}
		else {
			MessageDialog.openInformation(window.getShell(), "no.uio.ifi.refaktor", "This is not supported");
			return null;
		}
		
		try {
			changer.refactor(new NullProgressMonitor());
			MessageDialog.openInformation(window.getShell(), "no.uio.ifi.refaktor", changer.getClass() + " has been excuted: " + System.currentTimeMillis());
			return null;
		} catch (RefaktorChangerException e) {
			RefaktorDebug.log(e);
		} catch (CoreException e) {
			RefaktorDebug.log(e);
		}finally{
			RefaktorDebug.log("finished executing: " + (System.currentTimeMillis()-startTime) + " millisec");
		}
		
		MessageDialog.openInformation(window.getShell(), "no.uio.ifi.refaktor", changer.getClass() + " did not execute correctly");
		return null;
	}
	


	/**
	 * @param m the method that should be changed
	 * @return true if the subclass supports changing this method ({@link getChanger(IMethod method)} returns not null)
	 * 			false otherwise ({@link getChanger(IMethod method)} returns null)
	 */
	protected abstract boolean supports(IMethod m);
	/**
	 * @param p the project that should be changed
	 * @return true if the subclass supports changing this project ({@link getChanger(IProject project)} returns not null)
	 * 			false otherwise ({@link getChanger(IProject project)} returns null)
	 */
	protected abstract boolean supports(IProject p);

	/**
	 * @param method Method to be changed
	 * @return The changer to change the method if supports(IMethod m) returns true for subclass, null otherwise
	 */
	protected abstract Refactorer getChanger(IMethod method);
	/**
	 * @param project Project to be changed
	 * @return The changer to change the project if supports(IProject p) returns true for subclass, null otherwise
	 */
	protected abstract Refactorer getChanger(IProject project);
}