/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 * 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
 *

 *******************************************************************************/
package org.eclipse.dltk.internal.debug.ui.interpreters;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.dltk.core.environment.EnvironmentPathUtils;
import org.eclipse.dltk.core.environment.IFileHandle;
import org.eclipse.dltk.debug.ui.DLTKDebugUIPlugin;
import org.eclipse.dltk.debug.ui.IDLTKDebugUIConstants;
import org.eclipse.dltk.launching.LibraryLocation;
import org.eclipse.osgi.util.NLS;

/**
 * Wrapper for an original library location, to support editing.
 *
 */
public final class LibraryStandin {
	private IPath fLibraryLocation;

	/**
	 * Creates a new library standin on the given library location.
	 */
	public LibraryStandin(LibraryLocation libraryLocation) {
		fLibraryLocation = libraryLocation.getLibraryPath();
	}

	public LibraryStandin(IPath path) {
		fLibraryLocation = path;
	}

	/**
	 * Returns the InterpreterEnvironment library archive location.
	 *
	 * @return The InterpreterEnvironment library archive location.
	 */
	public String getLibraryPathString() {
		return EnvironmentPathUtils.getLocalPathString(fLibraryLocation);
	}

	@Override
	public boolean equals(Object obj) {
		if (obj instanceof LibraryStandin) {
			LibraryStandin lib = (LibraryStandin) obj;
			return fLibraryLocation.equals(lib.fLibraryLocation);
		}
		return false;
	}

	@Override
	public int hashCode() {
		return fLibraryLocation.hashCode();
	}

	/**
	 * Returns whether the given paths are equal - either may be
	 * <code>null</code>.
	 *
	 * @param path1
	 *            path to be compared
	 * @param path2
	 *            path to be compared
	 * @return whether the given paths are equal
	 */
	protected boolean equals(IPath path1, IPath path2) {
		return equalsOrNull(path1, path2);
	}

	/**
	 * Returns whether the given objects are equal - either may be
	 * <code>null</code>.
	 *
	 * @param o1
	 *            object to be compared
	 * @param o2
	 *            object to be compared
	 * @return whether the given objects are equal or both null
	 *
	 */
	private boolean equalsOrNull(Object o1, Object o2) {
		if (o1 == null) {
			return o2 == null;
		}
		if (o2 == null) {
			return false;
		}
		return o1.equals(o2);
	}

	/**
	 * Returns an equivalent library location.
	 *
	 * @return library location
	 */
	public LibraryLocation toLibraryLocation() {
		return new LibraryLocation(fLibraryLocation);
	}

	/**
	 * Returns a status for this library describing any error states
	 *
	 * @param environment
	 *
	 * @return
	 */
	public IStatus validate() {
		IFileHandle f = EnvironmentPathUtils.getFile(fLibraryLocation);
		if (!f.exists()) {
			return new Status(IStatus.ERROR, DLTKDebugUIPlugin.PLUGIN_ID,
					IDLTKDebugUIConstants.INTERNAL_ERROR,
					NLS.bind(InterpretersMessages.LibraryStandin_0,
							f.toString()),
					null);
		}
		return Status.OK_STATUS;
	}

}