/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package net.sourceforge.phpdt.internal.core;

import java.io.ByteArrayInputStream;
import java.io.UnsupportedEncodingException;

import net.sourceforge.phpdt.core.IBuffer;
import net.sourceforge.phpdt.core.ICompilationUnit;
import net.sourceforge.phpdt.core.IJavaElement;
import net.sourceforge.phpdt.core.IJavaModelStatus;
import net.sourceforge.phpdt.core.IJavaModelStatusConstants;
import net.sourceforge.phpdt.core.JavaModelException;
import net.sourceforge.phpdt.internal.core.util.Util;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.jobs.ISchedulingRule;

/**
 * Commits the contents of a working copy compilation unit to its original
 * element and resource, bringing the Java Model up-to-date with the current
 * contents of the working copy.
 * 
 * <p>
 * It is possible that the contents of the original resource have changed since
 * the working copy was created, in which case there is an update conflict. This
 * operation allows for two settings to resolve conflict set by the
 * <code>fForce</code> flag:
 * <ul>
 * <li>force flag is <code>false</code>- in this case an
 * <code>JavaModelException</code> is thrown</li>
 * <li>force flag is <code>true</code>- in this case the contents of the
 * working copy are applied to the underlying resource even though the working
 * copy was created before a subsequent change in the resource</li>
 * </ul>
 * 
 * <p>
 * The default conflict resolution setting is the force flag is
 * <code>false</code>
 * 
 * A JavaModelOperation exception is thrown either if the commit could not be
 * performed or if the new content of the compilation unit violates some Java
 * Model constraint (e.g. if the new package declaration doesn't match the name
 * of the folder containing the compilation unit).
 */
public class CommitWorkingCopyOperation extends JavaModelOperation {
	/**
	 * Constructs an operation to commit the contents of a working copy to its
	 * original compilation unit.
	 */
	public CommitWorkingCopyOperation(ICompilationUnit element, boolean force) {
		super(new IJavaElement[] { element }, force);
	}

	/**
	 * @exception JavaModelException
	 *                if setting the source of the original compilation unit
	 *                fails
	 */
	protected void executeOperation() throws JavaModelException {
		try {
			beginTask(Util.bind("workingCopy.commit"), 2); //$NON-NLS-1$
			CompilationUnit workingCopy = getCompilationUnit();
			IFile resource = (IFile) workingCopy.getResource();
			ICompilationUnit primary = workingCopy.getPrimary();
			boolean isPrimary = workingCopy.isPrimary();

			JavaElementDeltaBuilder deltaBuilder = null;
			// PackageFragmentRoot root =
			// (PackageFragmentRoot)workingCopy.getAncestor(IJavaElement.PACKAGE_FRAGMENT_ROOT);
			boolean isIncluded = !Util.isExcluded(workingCopy);
			// if (isPrimary || (root.isOnClasspath() && isIncluded &&
			// resource.isAccessible() &&
			// ProjectPrefUtil.isValidCompilationUnitName(workingCopy.getElementName())))
			// {
			if (isPrimary
					|| (isIncluded && resource.isAccessible() && Util
							.isValidCompilationUnitName(workingCopy
									.getElementName()))) {

				// force opening so that the delta builder can get the old info
				if (!isPrimary && !primary.isOpen()) {
					primary.open(null);
				}

				// creates the delta builder (this remembers the content of the
				// cu) if:
				// - it is not excluded
				// - and it is not a primary or it is a non-consistent primary
				if (isIncluded && (!isPrimary || !workingCopy.isConsistent())) {
					deltaBuilder = new JavaElementDeltaBuilder(primary);
				}

				// save the cu
				IBuffer primaryBuffer = primary.getBuffer();
				if (!isPrimary) {
					if (primaryBuffer == null)
						return;
					char[] primaryContents = primaryBuffer.getCharacters();
					boolean hasSaved = false;
					try {
						IBuffer workingCopyBuffer = workingCopy.getBuffer();
						if (workingCopyBuffer == null)
							return;
						primaryBuffer.setContents(workingCopyBuffer
								.getCharacters());
						primaryBuffer.save(this.progressMonitor, this.force);
						primary.makeConsistent(this);
						hasSaved = true;
					} finally {
						if (!hasSaved) {
							// restore original buffer contents since something
							// went wrong
							primaryBuffer.setContents(primaryContents);
						}
					}
				} else {
					// for a primary working copy no need to set the content of
					// the buffer again
					primaryBuffer.save(this.progressMonitor, this.force);
					primary.makeConsistent(this);
				}
			} else {
				// working copy on cu outside classpath OR resource doesn't
				// exist yet
				String encoding = null;
				try {
					encoding = resource.getCharset();
				} catch (CoreException ce) {
					// use no encoding
				}
				String contents = workingCopy.getSource();
				if (contents == null)
					return;
				try {
					byte[] bytes = encoding == null ? contents.getBytes()
							: contents.getBytes(encoding);
					ByteArrayInputStream stream = new ByteArrayInputStream(
							bytes);
					if (resource.exists()) {
						resource.setContents(stream,
								this.force ? IResource.FORCE
										| IResource.KEEP_HISTORY
										: IResource.KEEP_HISTORY, null);
					} else {
						resource.create(stream, this.force,
								this.progressMonitor);
					}
				} catch (CoreException e) {
					throw new JavaModelException(e);
				} catch (UnsupportedEncodingException e) {
					throw new JavaModelException(e,
							IJavaModelStatusConstants.IO_EXCEPTION);
				}

			}

			setAttribute(HAS_MODIFIED_RESOURCE_ATTR, TRUE);

			// make sure working copy is in sync
			workingCopy.updateTimeStamp((CompilationUnit) primary);
			workingCopy.makeConsistent(this);
			worked(1);

			// build the deltas
			if (deltaBuilder != null) {
				deltaBuilder.buildDeltas();

				// add the deltas to the list of deltas created during this
				// operation
				if (deltaBuilder.delta != null) {
					addDelta(deltaBuilder.delta);
				}
			}
			worked(1);
		} finally {
			done();
		}
	}

	/**
	 * Returns the compilation unit this operation is working on.
	 */
	protected CompilationUnit getCompilationUnit() {
		return (CompilationUnit) getElementToProcess();
	}

	protected ISchedulingRule getSchedulingRule() {
		IResource resource = getElementToProcess().getResource();
		IWorkspace workspace = resource.getWorkspace();
		if (resource.exists()) {
			return workspace.getRuleFactory().modifyRule(resource);
		} else {
			return workspace.getRuleFactory().createRule(resource);
		}
	}

	/**
	 * Possible failures:
	 * <ul>
	 * <li>INVALID_ELEMENT_TYPES - the compilation unit supplied to this
	 * operation is not a working copy
	 * <li>ELEMENT_NOT_PRESENT - the compilation unit the working copy is based
	 * on no longer exists.
	 * <li>UPDATE_CONFLICT - the original compilation unit has changed since
	 * the working copy was created and the operation specifies no force
	 * <li>READ_ONLY - the original compilation unit is in read-only mode
	 * </ul>
	 */
	public IJavaModelStatus verify() {
		CompilationUnit cu = getCompilationUnit();
		if (!cu.isWorkingCopy()) {
			return new JavaModelStatus(
					IJavaModelStatusConstants.INVALID_ELEMENT_TYPES, cu);
		}
		if (cu.hasResourceChanged() && !this.force) {
			// axelcl deleted start - force it to VERIFIED_OK, need to be fixed
			// return new
			// JavaModelStatus(IJavaModelStatusConstants.UPDATE_CONFLICT);
			// axelcl end
		}

		// no read-only check, since some repository adapters can change the
		// flag on save
		// operation.
		return JavaModelStatus.VERIFIED_OK;
	}
}