plugins/org.eclipse.gmf.xpand/src/org/eclipse/gmf/internal/xpand/build/WorkspaceModelRegistry.java

/*
 * Copyright (c) 2006, 2009 Borland Software Corporation
 * 
 * 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:
 *    Artem Tikhomirov (Borland) - initial API and implementation
 */
package org.eclipse.gmf.internal.xpand.build;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResourceDelta;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EPackage;
import org.eclipse.emf.ecore.plugin.EcorePlugin;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.gmf.internal.xpand.Activator;

/**
 * FIXME with the recent move of the context project knowledge into this class, there's no much value in
 * having this registry instantiated and invoked by builder. Instead, make it workspace-wide (though may filter project
 * based on xpandBuilder presence) and builder-independent (listen to changes, employ IResourceProxy)
 * 
 * @author artem
 */
class WorkspaceModelRegistry implements MetaModelSource {

	/**
	 * 
	 * It had been found that having gmfgraph.ecore / gmfgen.ecore from the workspace loaded tp this registry (by platform:resource URIs)
	 * leads to problems with binding QVTO utility calls, because the xPand code (from this class) supplies the EClass'es from workspace resources 
	 * while QVTO compiler expects the same-named classes from typed GMFGraphPackageImpl/GmfGenPackageImpl. 
	 * 
	 * While we are investigating the problem, as a workaround, we will allow to block all metamodles from given workspace 
	 * project to be loaded into this registry.
	 * 
	 * That is, {@link WorkspaceModelRegistry} in 3.0 release will IGNORE all workspace metamodels from the projects that has the settings file with this name.
	 * @see #380069  
	 */
	private static final String SETTINGS_IGNORE_PROJECT_METAMODELS = ".settings/org.eclipse.gmf.xpand.build.ignore-all-local-metamodels.txt";

	private static class Descriptor {

		final String workspacePath;

		final String nsURI;

		final Resource resource;

		public Descriptor(String workspacePath, String nsURI, Resource res) {
			assert workspacePath != null && nsURI != null && res != null;
			this.workspacePath = workspacePath;
			this.nsURI = nsURI;
			this.resource = res;
		}
	}

	private final Map<String, Descriptor> pathToDescriptor = new TreeMap<String, Descriptor>();

	private final Map<String, Descriptor> uriToDescriptor = new TreeMap<String, Descriptor>();

	private final IProject project;

	private boolean isInFullBuild;

	private boolean doneFullBuild;

	//	void DEBUG_DUMP() {
	//		System.err.println(">>> " + WorkspaceModelRegistry.class.getSimpleName());
	//		for (Map.Entry<String, Descriptor> e : uriToDescriptor.entrySet()) {
	//			assert e.getKey().equals(e.getValue().nsURI);
	//			System.err.println(e.getKey() + " ==> " + e.getValue().workspacePath);
	//		}
	//		System.err.println("<<< " + WorkspaceModelRegistry.class.getSimpleName());
	//	}

	public WorkspaceModelRegistry(IProject project, ResourceSet resolutionResourceSet) {
		assert project != null;
		this.project = project;
		resourceSet = resolutionResourceSet;
	}

	public WorkspaceModelRegistry(IProject project) {
		this(project, new ResourceSetImpl());
		resourceSet.getURIConverter().getURIMap().putAll(EcorePlugin.computePlatformURIMap());
	}

	private Map<String, EPackage> myReturnedResults = new HashMap<String, EPackage>();

	public EPackage find(String nsURI) {
		Descriptor d = uriToDescriptor.get(nsURI);
		return d == null ? null : (EPackage) d.resource.getContents().get(0);
	}

	public EPackage[] all() {
		if (!doneFullBuild) {
			try {
				// full build never ran, need to initialize data first.
				build(new NullProgressMonitor());
			} catch (CoreException ex) {
				Activator.log(ex.getStatus());
			}
		}
		EPackage[] rv = new EPackage[pathToDescriptor.size()];
		int i = 0;
		for (Descriptor d : pathToDescriptor.values()) {
			rv[i++] = (EPackage) d.resource.getContents().get(0);
		}
		return rv;
	}

	public void build(IProgressMonitor monitor) throws CoreException {
		if (isInFullBuild) {
			return;
		}
		try {
			isInFullBuild = true;
			EcoreModelResourceVisitor visitor = new EcoreModelResourceVisitor(monitor);
			project.accept(visitor);
			handleCollectedData(visitor);
			doneFullBuild = true;
		} finally {
			isInFullBuild = false;
		}
	}

	public void build(IResourceDelta delta, IProgressMonitor monitor) throws CoreException {
		assert delta.getResource().getProject() == project;
		if (isInFullBuild) {
			return;
		}
		EcoreModelResourceVisitor visitor = new EcoreModelResourceVisitor(monitor);
		delta.accept(visitor);
		handleCollectedData(visitor);
	}

	private void handleCollectedData(EcoreModelResourceVisitor visitor) {
		for (IFile f : visitor.getRemovedModelFiles()) {
			String workspacePath = getKeyPath(f);
			Descriptor d = pathToDescriptor.remove(workspacePath);
			if (d != null) {
				Descriptor d2 = uriToDescriptor.remove(d.nsURI);
				assert d2 == d;
				delist(d);
			}
		}
		Set<IFile> filesToAdd = new HashSet<IFile>(visitor.getNewModelFiles());
		for (IFile f : visitor.getChangedModelFiles()) {
			Descriptor d = pathToDescriptor.remove(getKeyPath(f));
			if (d != null) {
				Descriptor d2 = uriToDescriptor.remove(d.nsURI); // uri might be changed, let alone Descriptor is not modifyable
				assert d2 == d;
				delist(d);
			}
			filesToAdd.add(f);
		}
		for (IFile f : filesToAdd) {
			if (shouldIgnoreWorkspaceMetamodel(f)) {
				continue;
			}
			try {
				Resource r = attemptLoad(f);
				if (r != null && hasSuitableContent(r)) {
					Descriptor d = createDescriptor(f, r);
					assert d != null;
					pathToDescriptor.put(d.workspacePath, d);
					uriToDescriptor.put(d.nsURI, d);
				}
			} catch (Exception ex) {
				ex.printStackTrace();
				// ignore
			}
		}
	}

	private boolean shouldIgnoreWorkspaceMetamodel(IFile metamodelFile) {
		if (metamodelFile == null) {
			return false;
		}
		IFile ignoreProjectMetamodelsSettings = metamodelFile.getProject().getFile(SETTINGS_IGNORE_PROJECT_METAMODELS);
		return ignoreProjectMetamodelsSettings != null && ignoreProjectMetamodelsSettings.exists();
	}

	// TODO per-project?
	private final ResourceSet resourceSet;

	private Resource attemptLoad(IFile file) throws IOException {
		URI uri = URI.createPlatformResourceURI(file.getFullPath().toString(), false);
		Resource res = getResourceSet(file).getResource(uri, true);
		if (res == null) {
			throw new FileNotFoundException("Can't load model from " + file.getFullPath());
		}
		return res;
	}

	private ResourceSet getResourceSet(IFile file) {
		return resourceSet;
	}

	// works in pair with #createDescriptor - may extract these as interface to support models other than Ecore
	private boolean hasSuitableContent(Resource r) {
		assert r != null;
		return r.getContents().get(0) instanceof EPackage;
	}

	private Descriptor createDescriptor(IFile f, Resource res) {
		final String path = getKeyPath(f);
		EPackage p = (EPackage) res.getContents().get(0);
		final String nsURI = p.getNsURI();
		if (nsURI == null) {
			throw new IllegalArgumentException("Invalid model file (missed nsURI) " + path);
		}
		return new Descriptor(path, nsURI, res);
	}

	private void delist(Descriptor d) {
		d.resource.unload();
		d.resource.getResourceSet().getResources().remove(d.resource);
	}

	private String getKeyPath(IFile f) {
		return f.getFullPath().toString();
	}
}