/*
    * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
    * and other copyright owners as documented in the project's IP log.
    *
    * This program and the accompanying materials are made available
    * under the terms of the Eclipse Distribution License v1.0 which
    * accompanies this distribution, is reproduced below, and is
    * available at http://www.eclipse.org/org/documents/edl-v10.php
    *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or
   * without modification, are permitted provided that the following
   * conditions are met:
   *
   * - Redistributions of source code must retain the above copyright
   *   notice, this list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above
   *   copyright notice, this list of conditions and the following
   *   disclaimer in the documentation and/or other materials provided
   *   with the distribution.
   *
   * - Neither the name of the Eclipse Foundation, Inc. nor the
   *   names of its contributors may be used to endorse or promote
   *   products derived from this software without specific prior
   *   written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package org.eclipse.jgit.transport;
  
  import java.io.IOException;
  import java.text.MessageFormat;
  
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.RefUpdate;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.revwalk.RevWalk;
  
  /**
   * Represent request and status of a remote ref update. Specification is
   * provided by client, while status is handled by {@link PushProcess} class,
   * being read-only for client.
   * <p>
   * Client can create instances of this class directly, basing on user
   * specification and advertised refs ({@link Connection} or through
   * {@link Transport} helper methods. Apply this specification on remote
   * repository using
   * {@link Transport#push(org.eclipse.jgit.lib.ProgressMonitor, java.util.Collection)}
   * method.
   * </p>
   *
   */
  public class RemoteRefUpdate {
  	/**
  	 * Represent current status of a remote ref update.
  	 */
  	public static enum Status {
  		/**
  		 * Push process hasn't yet attempted to update this ref. This is the
  		 * default status, prior to push process execution.
  		 */
  		NOT_ATTEMPTED,
  
  		/**
  		 * Remote ref was up to date, there was no need to update anything.
  		 */
  		UP_TO_DATE,
  
  		/**
  		 * Remote ref update was rejected, as it would cause non fast-forward
  		 * update.
  		 */
  		REJECTED_NONFASTFORWARD,
  
  		/**
  		 * Remote ref update was rejected, because remote side doesn't
  		 * support/allow deleting refs.
  		 */
  		REJECTED_NODELETE,
  
  		/**
  		 * Remote ref update was rejected, because old object id on remote
 		 * repository wasn't the same as defined expected old object.
 		 */
 		REJECTED_REMOTE_CHANGED,
 
 		/**
 		 * Remote ref update was rejected for other reason, possibly described
 		 * in {@link RemoteRefUpdate#getMessage()}.
 		 */
 		REJECTED_OTHER_REASON,
 
 		/**
 		 * Remote ref didn't exist. Can occur on delete request of a non
 		 * existing ref.
 		 */
 		NON_EXISTING,
 
 		/**
 		 * Push process is awaiting update report from remote repository. This
 		 * is a temporary state or state after critical error in push process.
 		 */
 		AWAITING_REPORT,
 
 		/**
 		 * Remote ref was successfully updated.
 		 */
 		OK;
 	}
 
 	private final ObjectId expectedOldObjectId;
 
 	private final ObjectId newObjectId;
 
 	private final String remoteName;
 
 	private final TrackingRefUpdate trackingRefUpdate;
 
 	private final String srcRef;
 
 	private final boolean forceUpdate;
 
 	private Status status;
 
 	private boolean fastForward;
 
 	private String message;
 
 	private final Repository localDb;
 
 	private RefUpdate localUpdate;
 
 	/**
 	 * Construct remote ref update request by providing an update specification.
 	 * Object is created with default {@link Status#NOT_ATTEMPTED} status and no
 	 * message.
 	 *
 	 * @param localDb
 	 *            local repository to push from.
 	 * @param srcRef
 	 *            source revision - any string resolvable by
 	 *            {@link Repository#resolve(String)}. This resolves to the new
 	 *            object that the caller want remote ref to be after update. Use
 	 *            null or {@link ObjectId#zeroId()} string for delete request.
 	 * @param remoteName
 	 *            full name of a remote ref to update, e.g. "refs/heads/master"
 	 *            (no wildcard, no short name).
 	 * @param forceUpdate
 	 *            true when caller want remote ref to be updated regardless
 	 *            whether it is fast-forward update (old object is ancestor of
 	 *            new object).
 	 * @param localName
 	 *            optional full name of a local stored tracking branch, to
 	 *            update after push, e.g. "refs/remotes/zawir/dirty" (no
 	 *            wildcard, no short name); null if no local tracking branch
 	 *            should be updated.
 	 * @param expectedOldObjectId
 	 *            optional object id that caller is expecting, requiring to be
 	 *            advertised by remote side before update; update will take
 	 *            place ONLY if remote side advertise exactly this expected id;
 	 *            null if caller doesn't care what object id remote side
 	 *            advertise. Use {@link ObjectId#zeroId()} when expecting no
 	 *            remote ref with this name.
 	 * @throws IOException
 	 *             when I/O error occurred during creating
 	 *             {@link TrackingRefUpdate} for local tracking branch or srcRef
 	 *             can't be resolved to any object.
 	 * @throws IllegalArgumentException
 	 *             if some required parameter was null
 	 */
 	public RemoteRefUpdate(final Repository localDb, final String srcRef,
 			final String remoteName, final boolean forceUpdate,
 			final String localName, final ObjectId expectedOldObjectId)
 			throws IOException {
 		this(localDb, srcRef, srcRef != null ? localDb.resolve(srcRef)
 				: ObjectId.zeroId(), remoteName, forceUpdate, localName,
 				expectedOldObjectId);
 	}
 
 	/**
 	 * Construct remote ref update request by providing an update specification.
 	 * Object is created with default {@link Status#NOT_ATTEMPTED} status and no
 	 * message.
 	 *
 	 * @param localDb
 	 *            local repository to push from.
 	 * @param srcRef
 	 *            source revision. Use null to delete.
 	 * @param remoteName
 	 *            full name of a remote ref to update, e.g. "refs/heads/master"
 	 *            (no wildcard, no short name).
 	 * @param forceUpdate
 	 *            true when caller want remote ref to be updated regardless
 	 *            whether it is fast-forward update (old object is ancestor of
 	 *            new object).
 	 * @param localName
 	 *            optional full name of a local stored tracking branch, to
 	 *            update after push, e.g. "refs/remotes/zawir/dirty" (no
 	 *            wildcard, no short name); null if no local tracking branch
 	 *            should be updated.
 	 * @param expectedOldObjectId
 	 *            optional object id that caller is expecting, requiring to be
 	 *            advertised by remote side before update; update will take
 	 *            place ONLY if remote side advertise exactly this expected id;
 	 *            null if caller doesn't care what object id remote side
 	 *            advertise. Use {@link ObjectId#zeroId()} when expecting no
 	 *            remote ref with this name.
 	 * @throws IOException
 	 *             when I/O error occurred during creating
 	 *             {@link TrackingRefUpdate} for local tracking branch or srcRef
 	 *             can't be resolved to any object.
 	 * @throws IllegalArgumentException
 	 *             if some required parameter was null
 	 */
 	public RemoteRefUpdate(final Repository localDb, final Ref srcRef,
 			final String remoteName, final boolean forceUpdate,
 			final String localName, final ObjectId expectedOldObjectId)
 			throws IOException {
 		this(localDb, srcRef != null ? srcRef.getName() : null,
 				srcRef != null ? srcRef.getObjectId() : null, remoteName,
 				forceUpdate, localName, expectedOldObjectId);
 	}
 
 	/**
 	 * Construct remote ref update request by providing an update specification.
 	 * Object is created with default {@link Status#NOT_ATTEMPTED} status and no
 	 * message.
 	 *
 	 * @param localDb
 	 *            local repository to push from.
 	 * @param srcRef
 	 *            source revision to label srcId with. If null srcId.name() will
 	 *            be used instead.
 	 * @param srcId
 	 *            The new object that the caller wants remote ref to be after
 	 *            update. Use null or {@link ObjectId#zeroId()} for delete
 	 *            request.
 	 * @param remoteName
 	 *            full name of a remote ref to update, e.g. "refs/heads/master"
 	 *            (no wildcard, no short name).
 	 * @param forceUpdate
 	 *            true when caller want remote ref to be updated regardless
 	 *            whether it is fast-forward update (old object is ancestor of
 	 *            new object).
 	 * @param localName
 	 *            optional full name of a local stored tracking branch, to
 	 *            update after push, e.g. "refs/remotes/zawir/dirty" (no
 	 *            wildcard, no short name); null if no local tracking branch
 	 *            should be updated.
 	 * @param expectedOldObjectId
 	 *            optional object id that caller is expecting, requiring to be
 	 *            advertised by remote side before update; update will take
 	 *            place ONLY if remote side advertise exactly this expected id;
 	 *            null if caller doesn't care what object id remote side
 	 *            advertise. Use {@link ObjectId#zeroId()} when expecting no
 	 *            remote ref with this name.
 	 * @throws IOException
 	 *             when I/O error occurred during creating
 	 *             {@link TrackingRefUpdate} for local tracking branch or srcRef
 	 *             can't be resolved to any object.
 	 * @throws IllegalArgumentException
 	 *             if some required parameter was null
 	 */
 	public RemoteRefUpdate(final Repository localDb, final String srcRef,
 			final ObjectId srcId, final String remoteName,
 			final boolean forceUpdate, final String localName,
 			final ObjectId expectedOldObjectId) throws IOException {
 		if (remoteName == null)
 			throw new IllegalArgumentException(JGitText.get().remoteNameCantBeNull);
 		if (srcId == null && srcRef != null)
 			throw new IOException(MessageFormat.format(
 					JGitText.get().sourceRefDoesntResolveToAnyObject, srcRef));
 
 		if (srcRef != null)
 			this.srcRef = srcRef;
 		else if (srcId != null && !srcId.equals(ObjectId.zeroId()))
 			this.srcRef = srcId.name();
 		else
 			this.srcRef = null;
 
 		if (srcId != null)
 			this.newObjectId = srcId;
 		else
 			this.newObjectId = ObjectId.zeroId();
 
 		this.remoteName = remoteName;
 		this.forceUpdate = forceUpdate;
 		if (localName != null && localDb != null) {
 			localUpdate = localDb.updateRef(localName);
 			localUpdate.setForceUpdate(true);
 			localUpdate.setRefLogMessage("push", true); //$NON-NLS-1$
 			localUpdate.setNewObjectId(newObjectId);
 			trackingRefUpdate = new TrackingRefUpdate(
 					true,
 					remoteName,
 					localName,
 					localUpdate.getOldObjectId() != null
 						? localUpdate.getOldObjectId()
 						: ObjectId.zeroId(),
 					newObjectId);
 		} else
 			trackingRefUpdate = null;
 		this.localDb = localDb;
 		this.expectedOldObjectId = expectedOldObjectId;
 		this.status = Status.NOT_ATTEMPTED;
 	}
 
 	/**
 	 * Create a new instance of this object basing on existing instance for
 	 * configuration. State (like {@link #getMessage()}, {@link #getStatus()})
 	 * of base object is not shared. Expected old object id is set up from
 	 * scratch, as this constructor may be used for 2-stage push: first one
 	 * being dry run, second one being actual push.
 	 *
 	 * @param base
 	 *            configuration base.
 	 * @param newExpectedOldObjectId
 	 *            new expected object id value.
 	 * @throws IOException
 	 *             when I/O error occurred during creating
 	 *             {@link TrackingRefUpdate} for local tracking branch or srcRef
 	 *             of base object no longer can be resolved to any object.
 	 */
 	public RemoteRefUpdate(final RemoteRefUpdate base,
 			final ObjectId newExpectedOldObjectId) throws IOException {
 		this(base.localDb, base.srcRef, base.remoteName, base.forceUpdate,
 				(base.trackingRefUpdate == null ? null : base.trackingRefUpdate
 						.getLocalName()), newExpectedOldObjectId);
 	}
 
 	/**
 	 * @return expectedOldObjectId required to be advertised by remote side, as
 	 *         set in constructor; may be null.
 	 */
 	public ObjectId getExpectedOldObjectId() {
 		return expectedOldObjectId;
 	}
 
 	/**
 	 * @return true if some object is required to be advertised by remote side,
 	 *         as set in constructor; false otherwise.
 	 */
 	public boolean isExpectingOldObjectId() {
 		return expectedOldObjectId != null;
 	}
 
 	/**
 	 * @return newObjectId for remote ref, as set in constructor.
 	 */
 	public ObjectId getNewObjectId() {
 		return newObjectId;
 	}
 
 	/**
 	 * @return true if this update is deleting update; false otherwise.
 	 */
 	public boolean isDelete() {
 		return ObjectId.zeroId().equals(newObjectId);
 	}
 
 	/**
 	 * @return name of remote ref to update, as set in constructor.
 	 */
 	public String getRemoteName() {
 		return remoteName;
 	}
 
 	/**
 	 * @return local tracking branch update if localName was set in constructor.
 	 */
 	public TrackingRefUpdate getTrackingRefUpdate() {
 		return trackingRefUpdate;
 	}
 
 	/**
 	 * @return source revision as specified by user (in constructor), could be
 	 *         any string parseable by {@link Repository#resolve(String)}; can
 	 *         be null if specified that way in constructor - this stands for
 	 *         delete request.
 	 */
 	public String getSrcRef() {
 		return srcRef;
 	}
 
 	/**
 	 * @return true if user specified a local tracking branch for remote update;
 	 *         false otherwise.
 	 */
 	public boolean hasTrackingRefUpdate() {
 		return trackingRefUpdate != null;
 	}
 
 	/**
 	 * @return true if this update is forced regardless of old remote ref
 	 *         object; false otherwise.
 	 */
 	public boolean isForceUpdate() {
 		return forceUpdate;
 	}
 
 	/**
 	 * @return status of remote ref update operation.
 	 */
 	public Status getStatus() {
 		return status;
 	}
 
 	/**
 	 * Check whether update was fast-forward. Note that this result is
 	 * meaningful only after successful update (when status is {@link Status#OK}).
 	 *
 	 * @return true if update was fast-forward; false otherwise.
 	 */
 	public boolean isFastForward() {
 		return fastForward;
 	}
 
 	/**
 	 * @return message describing reasons of status when needed/possible; may be
 	 *         null.
 	 */
 	public String getMessage() {
 		return message;
 	}
 
 	void setStatus(final Status status) {
 		this.status = status;
 	}
 
 	void setFastForward(boolean fastForward) {
 		this.fastForward = fastForward;
 	}
 
 	void setMessage(final String message) {
 		this.message = message;
 	}
 
 	/**
 	 * Update locally stored tracking branch with the new object.
 	 *
 	 * @param walk
 	 *            walker used for checking update properties.
 	 * @throws IOException
 	 *             when I/O error occurred during update
 	 */
 	protected void updateTrackingRef(final RevWalk walk) throws IOException {
 		if (isDelete())
 			trackingRefUpdate.setResult(localUpdate.delete(walk));
 		else
 			trackingRefUpdate.setResult(localUpdate.update(walk));
 	}
 
 	@SuppressWarnings("nls")
 	@Override
 	public String toString() {
 		return "RemoteRefUpdate[remoteName="
 				+ remoteName
 				+ ", "
 				+ status
 				+ ", "
 				+ (expectedOldObjectId != null ? expectedOldObjectId.name()
 						: "(null)") + "..."
 				+ (newObjectId != null ? newObjectId.name() : "(null)")
 				+ (fastForward ? ", fastForward" : "")
  + ", srcRef=" + srcRef
 				+ (forceUpdate ? ", forceUpdate" : "") + ", message="
 				+ (message != null ? "\"" + message + "\"" : "null") + "]";
 	}
 }