package minmalworkingexample;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

import javax.inject.Inject;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IProjectDescription;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.resources.IncrementalProjectBuilder;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.swt.widgets.Display;
import org.eclipse.xtext.builder.nature.XtextNature;
import org.eclipse.xtext.junit4.InjectWith;
import org.eclipse.xtext.junit4.XtextRunner;
import org.eclipse.xtext.resource.IResourceDescriptions;
import org.eclipse.xtext.ui.XtextProjectHelper;
import org.eclipse.xtext.ui.resource.IResourceSetProvider;
import org.eclipse.xtext.ui.wizard.XtextNewProjectWizard;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.xtext.example.mydsl.MyDslUiInjectorProvider;
import org.xtext.example.mydsl.myDsl.Fragment;
import org.xtext.example.mydsl.myDsl.Greeting;
import org.xtext.example.mydsl.myDsl.Model;
import org.xtext.example.mydsl.myDsl.MyDslFactory;
import org.xtext.example.mydsl.myDsl.Person;

import utils.FileUtils;
import utils.XMIUtils;

@RunWith(XtextRunner.class)
@InjectWith(MyDslUiInjectorProvider.class)
public class TestClass {

	private static final String MODEL_FILE_NAME = "resources/model.xmi";
	private static final String TARGET_PROJECT_NAME = "TARGET";

	@Inject
	IResourceSetProvider resourceSetProvider;
	
	@Inject
	IResourceDescriptions desc;

	@BeforeClass
	public static void setUp() {
		System.out.println("SET UP START");
		// delete our dummy project (that we build during the test) if it exists.
		IWorkspaceRoot workspaceRoot = ResourcesPlugin.getWorkspace().getRoot();
		IProject targetProject = workspaceRoot.getProject(TARGET_PROJECT_NAME);
		if (targetProject.exists()) {
			try {
				targetProject.delete(true, true, new NullProgressMonitor());
			} catch (CoreException e) {
				e.printStackTrace();
				fail();
			}
		}
		waitForJobs();
		System.out.println("SET UP DONE");
	}

	/**
	 * This is the main test method.<br>
	 * It reads the XMI file from "/resources/model.xmi" and tries to save its contents to two different files.
	 */
	@Test
	public void runTest() {
		// enable the next line and the JUnit test will work and produce the expected output!
		// However, it is strongly discouraged in OSGI-Based environments.
		// MyDslStandaloneSetup.doSetup();
		EObject model = this.deserializeTestXMI();
		assertTrue("Could not deserialize XMI!", model != null && model instanceof Model);
		this.partitionAndSerialize((Model) model);
	}

	private EObject deserializeTestXMI() {
		File xmiFile = FileUtils.getBundleResource(Activator.getDefault().getBundle(), MODEL_FILE_NAME);
		return XMIUtils.deserializeFromXMIFile(xmiFile);
	}

	/**
	 * Partitions the model into files and saves them, using the Xtext serializer.<br>
	 * All instances of {@link Person} will go into the file <code>Persons.mydsl</code>, all instances of
	 * {@link Greeting} will go into the file <code>Greetings.mydsl</code>.
	 * 
	 * @param model
	 *            The model to partition and save
	 */
	private void partitionAndSerialize(final Model model) {
		IProject project = this.createTargetProject();
		Set<Person> persons = new HashSet<Person>();
		Set<Greeting> greetings = new HashSet<Greeting>();
		for (Fragment fragment : model.getFragments()) {
			if (fragment instanceof Person) {
				persons.add((Person) fragment);
			}
			if (fragment instanceof Greeting) {
				greetings.add((Greeting) fragment);
			}
		}
		assertEquals(2, greetings.size());
		assertEquals(2, persons.size());
		IFile greetingsFile = project.getFile("Greetings.mydsl");
		IFile personsFile = project.getFile("Persons.mydsl");
		try {
			this.createFile(greetingsFile);
			this.createFile(personsFile);
		} catch (CoreException e) {
			e.printStackTrace();
			fail();
		}
		ResourceSet resSet = this.resourceSetProvider.get(project);
		Resource greetingsResource = resSet.getResource(URI.createPlatformResourceURI(greetingsFile.getFullPath().toString()), true);
		Resource personsResource = resSet.getResource(URI.createPlatformResourceURI(personsFile.getFullPath().toString()), true);
		Model personsModel = MyDslFactory.eINSTANCE.createModel();
		personsModel.getFragments().addAll(persons);
		Model greetingsModel = MyDslFactory.eINSTANCE.createModel();
		greetingsModel.getFragments().addAll(greetings);
		greetingsResource.getContents().add(greetingsModel);
		personsResource.getContents().add(personsModel);
		try {
			personsResource.save(null);
			project.build(IncrementalProjectBuilder.FULL_BUILD, new NullProgressMonitor());
			waitForJobs();
			System.out.println(desc.getAllResourceDescriptions());
			
			
			greetingsResource.save(null);
		} catch (IOException e) {
			e.printStackTrace();
			fail();
		} catch (CoreException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	private IProject createTargetProject() {
		IWorkspaceRoot workspaceRoot = ResourcesPlugin.getWorkspace().getRoot();
		IProject project = workspaceRoot.getProject(TARGET_PROJECT_NAME);
		try {
			project.create(new NullProgressMonitor());
			project.open(new NullProgressMonitor());
			IProjectDescription description = project.getDescription();
			String[] natures = description.getNatureIds();
			String[] newnatures = new String[natures.length + 1];
			System.arraycopy(natures, 0, newnatures, 0, natures.length);
			newnatures[natures.length] = XtextProjectHelper.NATURE_ID;
			description.setNatureIds(newnatures);
			System.out.println(newnatures);
			project.setDescription(description, new NullProgressMonitor());
			XtextNature n = new XtextNature();
			n.setProject(project);
			n.configure();
		} catch (CoreException e) {
			e.printStackTrace();
			fail();
		}
		return project;
	}

	private void createFile(final IFile file) throws CoreException {
		file.create(new ByteArrayInputStream(new byte[0]), true, new NullProgressMonitor());
	}

	/**
	 * Perform post-test cleanup.
	 */
	@AfterClass
	public static void tearDown() throws Exception {
		// Dispose of test fixture.
		waitForJobs();
		// Add additional teardown code here.
	}

	/**
	 * Process UI input but do not return for the specified time interval.
	 * 
	 * @param waitTimeMillis
	 *            the number of milliseconds
	 */
	private static void delay(final long waitTimeMillis) {
		Display display = Display.getCurrent();

		// If this is the UI thread,
		// then process input.

		if (display != null) {
			long endTimeMillis = System.currentTimeMillis() + waitTimeMillis;
			while (System.currentTimeMillis() < endTimeMillis) {
				if (!display.readAndDispatch()) {
					display.sleep();
				}
			}
			display.update();
		}
		// Otherwise, perform a simple sleep.
		else {
			try {
				Thread.sleep(waitTimeMillis);
			} catch (InterruptedException e) {
				// Ignored.
			}
		}
	}

	/**
	 * Wait until all background tasks are complete.
	 */
	private static void waitForJobs() {
		while (!Job.getJobManager().isIdle()) {
			delay(1000);
		}
	}
}

personsResource.save(null);
project.build(IncrementalProjectBuilder.FULL_BUILD, new NullProgressMonitor());
waitForJobs();
System.out.println(desc.getAllResourceDescriptions());
greetingsResource.save(null);