AlterAttribute.java

/*****************************************************************************
 * Copyright (c) 2006-2013, Cloudsmith Inc.
 * The code, documentation and other materials contained herein have been
 * licensed under the Eclipse Public License - v 1.0 by the copyright holder
 * listed above, as the Initial Contributor under such license. The text of
 * such license is available at www.eclipse.org.
 *****************************************************************************/
package org.eclipse.buckminster.core.cspecext.model;

import java.util.Map;
import java.util.Set;

import org.eclipse.buckminster.core.common.model.Documentation;
import org.eclipse.buckminster.core.cspec.builder.MissingPathException;
import org.eclipse.buckminster.core.cspec.builder.TopLevelAttributeBuilder;
import org.eclipse.buckminster.core.cspec.model.PathAlreadyDefinedException;
import org.eclipse.buckminster.core.cspec.model.PropertyAlreadyDefinedException;
import org.eclipse.buckminster.core.cspec.model.TopLevelAttribute;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;

/**
 * @author Thomas Hallgren
 */
public abstract class AlterAttribute<T extends TopLevelAttribute> {
	public static final String ELEM_ALTER_INSTALLER_HINTS = "alterInstallerHints"; //$NON-NLS-1$

	static void alterPaths(String compName, String attrName, Set<IPath> original, Set<IPath> added, Set<IPath> removed) throws CoreException {
		if (!(added.isEmpty() && removed.isEmpty())) {
			for (IPath path : removed)
				if (!original.contains(path))
					throw new MissingPathException(compName, attrName, path);

			for (IPath path : added)
				if (original.contains(path))
					throw new PathAlreadyDefinedException(compName, attrName, path);

			original.addAll(original);
			original.removeAll(removed);
			original.addAll(added);
		}
	}

	static void performPropertyAlterations(String compName, String attrName, String propertyCategory, Map<String, String> original,
			Map<String, String> altered, Map<String, String> added, Set<String> removed) throws CoreException {
		// Assert that all hints to remove really exists
		//
		if (removed.isEmpty() && altered.isEmpty() && added.isEmpty())
			return;

		for (String key : removed)
			if (!original.containsKey(key))
				throw new MissingPropertyException(compName, attrName, propertyCategory, key);

		// Assert that all hints to be altered really exists
		//
		for (String key : altered.keySet())
			if (!original.containsKey(key))
				throw new MissingPropertyException(compName, attrName, propertyCategory, key);

		// Assert that we don't already have hints to be added
		//
		for (String key : added.keySet())
			if (original.containsKey(key))
				throw new PropertyAlreadyDefinedException(compName, attrName, propertyCategory, key);

		for (String key : removed)
			original.remove(key);
		original.putAll(added);
		original.putAll(altered);
	}

	private final T base;

	protected AlterAttribute(T base, Set<String> removedHints, Map<String, String> alteredHints) {
		this.base = base;
	}

	/**
	 * Creates a new Attribute instance from the <code>originalAttribute</code>
	 * that has the alterations defined by this instance applied.
	 * 
	 * @param name
	 *            The original attribute.
	 * @throws CoreException
	 */
	public abstract void alterAttribute(TopLevelAttributeBuilder attrBld) throws CoreException;

	public void alterDocumentation(TopLevelAttributeBuilder original) {
		Documentation origDoc = original.getDocumentation();
		Documentation baseDoc = base.getDocumentation();
		original.setDocumentation(origDoc == null ? baseDoc : origDoc.merge(baseDoc));
	}

	/**
	 * Returns the name of this alteration. The name must correspond to the
	 * attribute for which the alteration will be applied.
	 * 
	 * @return The name of the alteration.
	 */
	public String getName() {
		return base.getName();
	}

	/**
	 * Checks if this alteration is applicable for the given attribute with
	 * respect to its type.
	 * 
	 * @param originalAttribute
	 *            The attribute to check
	 * @return true if the type is conformant.
	 */
	public boolean isTypeConformant(TopLevelAttribute origAttr) {
		return origAttr.getClass().equals(base.getClass());
	}

	/**
	 * Returns the base for the alteration image. The base represents all
	 * attribute chagnes and collection additions. Collection removals and
	 * alterations to collection elements will be handled by extra additions.
	 * 
	 * @return THe base for the alteration image.
	 */
	protected final T getBase() {
		return base;
	}
}