/*******************************************************************************
 * Copyright (c) 2009 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * Contributors:
 * IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.common.jdt.internal.javalite;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.eclipse.core.resources.IContainer;
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.jdt.core.IClasspathEntry;
import org.eclipse.jst.common.frameworks.CommonFrameworksPlugin;
import org.eclipse.wst.common.componentcore.ComponentCore;
import org.eclipse.wst.common.componentcore.resources.IVirtualComponent;
import org.eclipse.wst.common.componentcore.resources.IVirtualResource;

public final class JavaLiteUtilities {

	/**
	 * Returns the Java source (i.e. where the .java files are) IContainers for
	 * the specified IJavaProjectLite
	 * 
	 * @param javaProjectLite
	 * @return
	 */
	public final static List<IContainer> getJavaSourceContainers(final IJavaProjectLite javaProjectLite) {
		IClasspathEntry[] entries = javaProjectLite.readRawClasspath();
		List<IContainer> containers = new ArrayList<IContainer>();
		for (IClasspathEntry entry : entries) {
			if (entry.getEntryKind() == IClasspathEntry.CPE_SOURCE && entry.getPath().segmentCount() > 0) {
				IContainer container = null;
				if( entry.getPath().segmentCount() == 1 )
					container = ResourcesPlugin.getWorkspace().getRoot().getProject(entry.getPath().segment(0));
				else
					container = ResourcesPlugin.getWorkspace().getRoot().getFolder(entry.getPath());
				if( !containers.contains(container))
					containers.add(container);
			}
		}
		return containers;
	}

	/**
	 * Returns the Java source (i.e. where the compiled .class files are) IContainers for
	 * the specified IJavaProjectLite
	 * 
	 * @param javaProjectLite
	 * @return
	 */
	public final static List<IContainer> getJavaOutputContainers(final IJavaProjectLite javaProjectLite) {
		List<IContainer> containers = new ArrayList<IContainer>();
		IContainer defaultOutputContainer = getDefaultJavaOutputContainer(javaProjectLite);
		containers.add(defaultOutputContainer);
		IClasspathEntry[] entries = javaProjectLite.readRawClasspath();
		for (IClasspathEntry entry : entries) {
			if (entry.getEntryKind() == IClasspathEntry.CPE_SOURCE) {
				IContainer outputContainer = getJavaOutputContainer(javaProjectLite, entry);
				if (!containers.contains(outputContainer)) {
					containers.add(outputContainer);
				}
			}
		}
		return containers;
	}

	private static enum JavaContainerType {
		SOURCE, OUTPUT
	}

	/**
	 * Returns all Java output (i.e. where the compiled .class files are)
	 * IContainers whose source is explicitly mapped by the specified component,
	 * or if the output container itself is explicitly mapped.
	 * 
	 * @param virtualComponent
	 * @return
	 */
	public static List<IContainer> getJavaOutputContainers(IVirtualComponent virtualComponent) {
		return getJavaContainers(virtualComponent, JavaContainerType.OUTPUT);
	}

	/**
	 * Returns all Java source (i.e. where the .java files are) IContainers
	 * explicitly mapped by the specified component.
	 * 
	 * @param virtualComponent
	 * @return
	 */
	public static List<IContainer> getJavaSourceContainers(IVirtualComponent virtualComponent) {
		return getJavaContainers(virtualComponent, JavaContainerType.SOURCE);
	}

	private static List<IContainer> getJavaContainers(IVirtualComponent virtualComponent, JavaContainerType javaContainerType) {
		if (virtualComponent.isBinary()) {
			return Collections.emptyList();
		}
		IProject project = virtualComponent.getProject();
		try {
			if (!project.hasNature(JavaCoreLite.NATURE_ID)) {
				return Collections.emptyList();
			}
		} catch (CoreException e) {
			CommonFrameworksPlugin.logError(e);
			return Collections.emptyList();
		}

		IJavaProjectLite javaProjectLite = JavaCoreLite.create(project);
		List<IContainer> containers = new ArrayList<IContainer>();
		if (javaContainerType == JavaContainerType.OUTPUT) {
			IContainer defaultOutputContainer = getDefaultJavaOutputContainer(javaProjectLite);
			IVirtualResource[] virtualResources = ComponentCore.createResources(defaultOutputContainer);
			for (IVirtualResource virtualResource : virtualResources) {
				if (virtualResource.getComponent().equals(virtualComponent)) {
					containers.add(defaultOutputContainer);
					break;
				}
			}
		}
		IClasspathEntry[] entries = javaProjectLite.readRawClasspath();
		for (IClasspathEntry entry : entries) {
			if (entry.getEntryKind() == IClasspathEntry.CPE_SOURCE) {
				IPath sourcePath = entry.getPath().removeFirstSegments(1); // remove the project from the path
				IContainer sourceContainer = sourcePath.segmentCount() == 0 ? project : project.getFolder(sourcePath);
				if (sourceContainer != null) {
					IVirtualResource[] virtualResources = ComponentCore.createResources(sourceContainer);
					for (IVirtualResource virtualResource : virtualResources) {
						if (virtualResource.getComponent().equals(virtualComponent)) {
							switch (javaContainerType) {
							case SOURCE:
								if (!containers.contains(sourceContainer)) {
									containers.add(sourceContainer);
								}
								break;
							case OUTPUT:
								IContainer outputContainer = getJavaOutputContainer(javaProjectLite, entry);
								if (!containers.contains(outputContainer)) {
									containers.add(outputContainer);
								}
								break;
							default:
							}
						}
					}
				}
			}
		}
		return containers;
	}

	/**
	 * Returns the default Java output IContainer (i.e. where the compiled
	 * .class files go)
	 * 
	 * @param javaProjectLite
	 * @return
	 */
	public static IContainer getDefaultJavaOutputContainer(IJavaProjectLite javaProjectLite) {
		IProject project = javaProjectLite.getProject();
		IPath defaultOutputPath = javaProjectLite.readOutputLocation();
		if (defaultOutputPath.segmentCount() == 1) {
			return project;
		}
		return project.getFolder(defaultOutputPath.removeFirstSegments(1));
	}

	/**
	 * Returns the Java output (i.e. where the compiled .class files go)
	 * IContainer for the specified IClasspathEntry
	 * 
	 * @param javaProjectLite
	 * @param entry
	 * @return
	 */
	public static IContainer getJavaOutputContainer(IJavaProjectLite javaProjectLite, IClasspathEntry entry) {
		IProject project = javaProjectLite.getProject();
		IPath outputPath = entry.getOutputLocation();
		if (outputPath != null) {
			return project.getFolder(outputPath.removeFirstSegments(1));
		}
		return getDefaultJavaOutputContainer(javaProjectLite);
	}
}