/*******************************************************************************
 * Copyright (c) 2008, 2016 xored software, Inc.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     xored software, Inc. - initial API and Implementation (Alex Panchenko)
 *******************************************************************************/
package org.eclipse.dltk.ruby.internal.debug.ui.console;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.core.DLTKLanguageManager;
import org.eclipse.dltk.core.IDLTKLanguageToolkit;
import org.eclipse.dltk.core.IProjectFragment;
import org.eclipse.dltk.core.IScriptFolder;
import org.eclipse.dltk.core.IScriptProject;
import org.eclipse.dltk.core.ISourceModule;
import org.eclipse.dltk.core.ModelException;
import org.eclipse.dltk.core.environment.EnvironmentPathUtils;
import org.eclipse.dltk.core.search.IDLTKSearchScope;
import org.eclipse.dltk.core.search.SearchEngine;
import org.eclipse.dltk.internal.core.util.Util;

public class RubyConsoleSourceModuleLookup {

	private final IDLTKSearchScope scope;

	public RubyConsoleSourceModuleLookup(IDLTKLanguageToolkit toolkit) {
		scope = SearchEngine.createWorkspaceScope(toolkit);
	}

	private IProject[] getAllProjects() {
		return ResourcesPlugin.getWorkspace().getRoot().getProjects();
	}

	private boolean checkScope(IProject project, IPath[] scopeProjectsAndZips) {
		final IPath location = project.getFullPath();
		for (int j = 0; j < scopeProjectsAndZips.length; j++) {
			if (scopeProjectsAndZips[j].equals(location)) {
				return true;
			}
		}
		return false;
	}

	public ISourceModule findSourceModuleByLocalPath(final IPath path) {
		final boolean isFullPath = EnvironmentPathUtils.isFull(path);
		final IProject[] projects = getAllProjects();
		final IPath[] enclosingProjectsAndZips = scope
				.enclosingProjectsAndZips();
		for (int i = 0, max = projects.length; i < max; i++) {
			try {
				final IProject project = projects[i];
				if (!checkScope(project, enclosingProjectsAndZips)) {
					continue;
				}
				if (!project.isAccessible()
						|| !DLTKLanguageManager.hasScriptNature(project))
					continue;

				IScriptProject scriptProject = DLTKCore.create(project);
				final ISourceModule module = findInProject(scriptProject, path,
						isFullPath);
				if (module != null) {
					return module.exists() ? module : null;
				}

			} catch (CoreException e) {
				// CoreException from hasNature - should not happen since we
				// check that the project is accessible
				// ModelException from getProjectFragments - a problem occurred
				// while accessing project: nothing we can do, ignore
			}
		}
		return null;
	}

	public static boolean isIncluded(IProjectFragment fragment, IPath path) {
		final IProjectFragment root = fragment;
		return !Util.isExcluded(path, root, false);
	}

	private ISourceModule findInProject(IScriptProject scriptProject,
			IPath path, boolean isFullPath) throws ModelException {
		IProjectFragment[] roots = scriptProject.getProjectFragments();
		for (int j = 0, rootCount = roots.length; j < rootCount; j++) {
			final IProjectFragment root = roots[j];
			IPath rootPath = root.getPath();
			if (!isFullPath) {
				rootPath = EnvironmentPathUtils.getLocalPath(rootPath);
			}
			if (rootPath.isPrefixOf(path) && isIncluded(root, path)) {
				IPath localPath = path.setDevice(null).removeFirstSegments(
						rootPath.segmentCount());
				if (localPath.segmentCount() >= 1) {
					final IScriptFolder folder;
					if (localPath.segmentCount() > 1) {
						folder = root.getScriptFolder(localPath
								.removeLastSegments(1));
					} else {
						folder = root.getScriptFolder(Path.EMPTY);
					}
					return folder.getSourceModule(localPath.lastSegment());
				}
			}
		}
		return null;
	}

}