/*******************************************************************************
 * Copyright (c) 2008, 2017 xored software, Inc.
 *
 * 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:
 *     xored software, Inc. - initial API and Implementation (Alex Panchenko)
 *******************************************************************************/
package org.eclipse.dltk.core.search.indexing.core;

import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.core.IDLTKLanguageToolkit;
import org.eclipse.dltk.core.IExternalSourceModule;
import org.eclipse.dltk.core.IModelElement;
import org.eclipse.dltk.core.IModelElementVisitor;
import org.eclipse.dltk.core.IProjectFragment;
import org.eclipse.dltk.core.ISourceModule;
import org.eclipse.dltk.core.ModelException;
import org.eclipse.dltk.core.environment.EnvironmentManager;
import org.eclipse.dltk.core.environment.EnvironmentPathUtils;
import org.eclipse.dltk.core.environment.IEnvironment;
import org.eclipse.dltk.core.environment.IFileHandle;
import org.eclipse.dltk.core.search.index.Index;
import org.eclipse.dltk.core.search.indexing.IProjectIndexer;
import org.eclipse.dltk.core.search.indexing.ReadWriteMonitor;
import org.eclipse.dltk.internal.core.BuiltinSourceModule;
import org.eclipse.dltk.internal.core.ModelManager;

public class ExternalProjectFragmentRequest extends IndexRequest {

	protected final IProjectFragment fragment;
	protected final IDLTKLanguageToolkit toolkit;

	public ExternalProjectFragmentRequest(IProjectIndexer indexer,
			IProjectFragment fragment, IDLTKLanguageToolkit toolkit) {
		super(indexer);
		this.fragment = fragment;
		this.toolkit = toolkit;
	}

	@Override
	protected String getName() {
		return fragment.getElementName();
	}

	@Override
	protected void run() throws CoreException, IOException {
		IEnvironment environment = EnvironmentManager
				.getEnvironment(fragment.getScriptProject());
		if (environment == null || !environment.connect()) {
			return;
		}
		final Set<ISourceModule> modules = getExternalSourceModules();
		final Index index = getIndexer().getProjectFragmentIndex(fragment);
		if (index == null) {
			return;
		}
		final IPath containerPath = fragment.getPath();
		Set<IFileHandle> parentFolders = new HashSet<>();
		final List<Object> changes = checkChanges(index, modules, containerPath,
				getEnvironment(), parentFolders);
		if (DEBUG) {
			log("changes.size=" + changes.size()); //$NON-NLS-1$
		}
		if (changes.isEmpty()) {
			return;
		}
		final ReadWriteMonitor imon = index.monitor;
		imon.enterWrite();
		try {
			for (Iterator<Object> i = changes.iterator(); !isCancelled
					&& i.hasNext();) {
				final Object change = i.next();
				if (change instanceof String) {
					index.remove((String) change);
				} else if (change instanceof ISourceModule) {
					ISourceModule module = (ISourceModule) change;
					IFileHandle file = EnvironmentPathUtils.getFile(module,
							false);
					if (file != null && changes.size() > 1) {
						IFileHandle parentHandle = file.getParent();
						if (parentHandle != null && parentFolders
								.add(parentHandle.getParent())) {
							ModelManager.getModelManager().getCoreCache()
									.updateFolderTimestamps(parentHandle);
						}
					}
					getIndexer().indexSourceModule(index, toolkit, module,
							containerPath);
				}
			}

		} catch (Throwable e) {
			e.printStackTrace();
		} finally {
			try {
				index.save();
			} catch (IOException e) {
				DLTKCore.error("error saving index", e); //$NON-NLS-1$
			} finally {
				imon.exitWrite();
			}
		}
	}

	protected IEnvironment getEnvironment() {
		return EnvironmentManager.getEnvironment(fragment);
	}

	static class ExternalModuleVisitor implements IModelElementVisitor {
		final Set<ISourceModule> modules = new HashSet<>();

		@Override
		public boolean visit(IModelElement element) {
			if (element.getElementType() == IModelElement.SOURCE_MODULE) {
				if (element instanceof IExternalSourceModule
						|| element instanceof BuiltinSourceModule
						|| ((ISourceModule) element).isBinary()) {
					modules.add((ISourceModule) element);
				}
				return false;
			}
			return true;
		}
	}

	private Set<ISourceModule> getExternalSourceModules()
			throws ModelException {
		final ExternalModuleVisitor visitor = new ExternalModuleVisitor();
		fragment.accept(visitor);
		return visitor.modules;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result
				+ ((fragment == null) ? 0 : fragment.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (!super.equals(obj))
			return false;
		if (getClass() != obj.getClass())
			return false;
		ExternalProjectFragmentRequest other = (ExternalProjectFragmentRequest) obj;
		if (fragment == null) {
			if (other.fragment != null)
				return false;
		} else if (!fragment.equals(other.fragment))
			return false;
		return true;
	}
}