/*
    * Copyright (C) 2008-2010, Google Inc.
    * 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
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   *   with the distribution.
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   * - Neither the name of the Eclipse Foundation, Inc. nor the
   *   names of its contributors may be used to endorse or promote
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  package org.eclipse.jgit.transport;
  
  import static org.eclipse.jgit.lib.Constants.HEAD;
  import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_ATOMIC;
  import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_PUSH_OPTIONS;
  import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_REPORT_STATUS;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.eclipse.jgit.annotations.Nullable;
  import org.eclipse.jgit.errors.UnpackException;
  import org.eclipse.jgit.lib.ConfigConstants;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.NullProgressMonitor;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.revwalk.RevWalk;
  import org.eclipse.jgit.transport.ReceiveCommand.Result;
  import org.eclipse.jgit.transport.RefAdvertiser.PacketLineOutRefAdvertiser;
  
  /**
   * Implements the server side of a push connection, receiving objects.
   */
  public class ReceivePack extends BaseReceivePack {
  	/** Hook to validate the update commands before execution. */
  	private PreReceiveHook preReceive;
  
  	/** Hook to report on the commands after execution. */
  	private PostReceiveHook postReceive;
  
  	/** If {@link BasePackPushConnection#CAPABILITY_REPORT_STATUS} is enabled. */
  	private boolean reportStatus;
  
  	/** Whether the client intends to use push options. */
  	private boolean usePushOptions;
  	private List<String> pushOptions;
  
  	/**
  	 * Create a new pack receive for an open repository.
  	 *
  	 * @param into
  	 *            the destination repository.
  	 */
  	public ReceivePack(Repository into) {
  		super(into);
  		preReceive = PreReceiveHook.NULL;
  		postReceive = PostReceiveHook.NULL;
  	}
 
 	/**
 	 * Get the repository this receive completes into.
 	 *
 	 * @return the repository this receive completes into.
 	 */
 	@Override
 	public final Repository getRepository() {
 		return db;
 	}
 
 	/**
 	 * Get the RevWalk instance used by this connection.
 	 *
 	 * @return the RevWalk instance used by this connection.
 	 */
 	@Override
 	public final RevWalk getRevWalk() {
 		return walk;
 	}
 
 	/**
 	 * Get refs which were advertised to the client.
 	 *
 	 * @return all refs which were advertised to the client, or null if
 	 *         {@link #setAdvertisedRefs(Map, Set)} has not been called yet.
 	 */
 	@Override
 	public final Map<String, Ref> getAdvertisedRefs() {
 		return refs;
 	}
 
 	/**
 	 * Set the refs advertised by this ReceivePack.
 	 * <p>
 	 * Intended to be called from a
 	 * {@link org.eclipse.jgit.transport.PreReceiveHook}.
 	 *
 	 * @param allRefs
 	 *            explicit set of references to claim as advertised by this
 	 *            ReceivePack instance. This overrides any references that may
 	 *            exist in the source repository. The map is passed to the
 	 *            configured {@link #getRefFilter()}. If null, assumes all refs
 	 *            were advertised.
 	 * @param additionalHaves
 	 *            explicit set of additional haves to claim as advertised. If
 	 *            null, assumes the default set of additional haves from the
 	 *            repository.
 	 */
 	@Override
 	public void setAdvertisedRefs(Map<String, Ref> allRefs, Set<ObjectId> additionalHaves) {
 		refs = allRefs != null ? allRefs : db.getAllRefs();
 		refs = refFilter.filter(refs);
 		advertisedHaves.clear();
 
 		Ref head = refs.get(HEAD);
 		if (head != null && head.isSymbolic()) {
 			refs.remove(HEAD);
 		}
 
 		for (Ref ref : refs.values()) {
 			if (ref.getObjectId() != null) {
 				advertisedHaves.add(ref.getObjectId());
 			}
 		}
 		if (additionalHaves != null) {
 			advertisedHaves.addAll(additionalHaves);
 		} else {
 			advertisedHaves.addAll(db.getAdditionalHaves());
 		}
 	}
 
 	/**
 	 * Get the push certificate used to verify the pusher's identity.
 	 * <p>
 	 * Only valid after commands are read from the wire.
 	 *
 	 * @return the parsed certificate, or null if push certificates are disabled
 	 *         or no cert was presented by the client.
 	 * @since 4.1
 	 */
 	@Override
 	public PushCertificate getPushCertificate() {
 		return pushCert;
 	}
 
 	/**
 	 * Set the push certificate used to verify the pusher's identity.
 	 * <p>
 	 * Should only be called if reconstructing an instance without going through
 	 * the normal {@link #recvCommands()} flow.
 	 *
 	 * @param cert
 	 *            the push certificate to set.
 	 * @since 4.1
 	 */
 	@Override
 	public void setPushCertificate(PushCertificate cert) {
 		pushCert = cert;
 	}
 
 	/**
 	 * Gets an unmodifiable view of the option strings associated with the push.
 	 *
 	 * @return an unmodifiable view of pushOptions, or null (if pushOptions is).
 	 * @since 4.5
 	 */
 	@Nullable
 	public List<String> getPushOptions() {
 		if (isAllowPushOptions() && usePushOptions) {
 			return Collections.unmodifiableList(pushOptions);
 		}
 
 		// The client doesn't support push options. Return null to
 		// distinguish this from the case where the client declared support
 		// for push options and sent an empty list of them.
 		return null;
 	}
 
 	/**
 	 * Set the push options supplied by the client.
 	 * <p>
 	 * Should only be called if reconstructing an instance without going through
 	 * the normal {@link #recvCommands()} flow.
 	 *
 	 * @param options
 	 *            the list of options supplied by the client. The
 	 *            {@code ReceivePack} instance takes ownership of this list.
 	 *            Callers are encouraged to first create a copy if the list may
 	 *            be modified later.
 	 * @since 4.5
 	 */
 	public void setPushOptions(@Nullable List<String> options) {
 		usePushOptions = options != null;
 		pushOptions = options;
 	}
 
 	/**
 	 * Get the hook invoked before updates occur.
 	 *
 	 * @return the hook invoked before updates occur.
 	 */
 	public PreReceiveHook getPreReceiveHook() {
 		return preReceive;
 	}
 
 	/**
 	 * Set the hook which is invoked prior to commands being executed.
 	 * <p>
 	 * Only valid commands (those which have no obvious errors according to the
 	 * received input and this instance's configuration) are passed into the
 	 * hook. The hook may mark a command with a result of any value other than
 	 * {@link org.eclipse.jgit.transport.ReceiveCommand.Result#NOT_ATTEMPTED} to
 	 * block its execution.
 	 * <p>
 	 * The hook may be called with an empty command collection if the current
 	 * set is completely invalid.
 	 *
 	 * @param h
 	 *            the hook instance; may be null to disable the hook.
 	 */
 	public void setPreReceiveHook(PreReceiveHook h) {
 		preReceive = h != null ? h : PreReceiveHook.NULL;
 	}
 
 	/**
 	 * Get the hook invoked after updates occur.
 	 *
 	 * @return the hook invoked after updates occur.
 	 */
 	public PostReceiveHook getPostReceiveHook() {
 		return postReceive;
 	}
 
 	/**
 	 * Set the hook which is invoked after commands are executed.
 	 * <p>
 	 * Only successful commands (type is
 	 * {@link org.eclipse.jgit.transport.ReceiveCommand.Result#OK}) are passed
 	 * into the hook. The hook may be called with an empty command collection if
 	 * the current set all resulted in an error.
 	 *
 	 * @param h
 	 *            the hook instance; may be null to disable the hook.
 	 */
 	public void setPostReceiveHook(PostReceiveHook h) {
 		postReceive = h != null ? h : PostReceiveHook.NULL;
 	}
 
 	/**
 	 * Set whether this class will report command failures as warning messages
 	 * before sending the command results.
 	 *
 	 * @param echo
 	 *            if true this class will report command failures as warning
 	 *            messages before sending the command results. This is usually
 	 *            not necessary, but may help buggy Git clients that discard the
 	 *            errors when all branches fail.
 	 * @deprecated no widely used Git versions need this any more
 	 */
 	@Deprecated
 	public void setEchoCommandFailures(boolean echo) {
 		// No-op.
 	}
 
 	/**
 	 * Execute the receive task on the socket.
 	 *
 	 * @param input
 	 *            raw input to read client commands and pack data from. Caller
 	 *            must ensure the input is buffered, otherwise read performance
 	 *            may suffer.
 	 * @param output
 	 *            response back to the Git network client. Caller must ensure
 	 *            the output is buffered, otherwise write performance may
 	 *            suffer.
 	 * @param messages
 	 *            secondary "notice" channel to send additional messages out
 	 *            through. When run over SSH this should be tied back to the
 	 *            standard error channel of the command execution. For most
 	 *            other network connections this should be null.
 	 * @throws java.io.IOException
 	 */
 	public void receive(final InputStream input, final OutputStream output,
 			final OutputStream messages) throws IOException {
 		init(input, output, messages);
 		try {
 			service();
 		} finally {
 			try {
 				close();
 			} finally {
 				release();
 			}
 		}
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	protected void enableCapabilities() {
 		reportStatus = isCapabilityEnabled(CAPABILITY_REPORT_STATUS);
 		usePushOptions = isCapabilityEnabled(CAPABILITY_PUSH_OPTIONS);
 		super.enableCapabilities();
 	}
 
 	@Override
 	void readPostCommands(PacketLineIn in) throws IOException {
 		if (usePushOptions) {
 			pushOptions = new ArrayList<>(4);
 			for (;;) {
 				String option = in.readString();
 				if (option == PacketLineIn.END) {
 					break;
 				}
 				pushOptions.add(option);
 			}
 		}
 	}
 
 	private void service() throws IOException {
 		if (isBiDirectionalPipe()) {
 			sendAdvertisedRefs(new PacketLineOutRefAdvertiser(pckOut));
 			pckOut.flush();
 		} else
 			getAdvertisedOrDefaultRefs();
 		if (hasError())
 			return;
 		recvCommands();
 		if (hasCommands()) {
 			Throwable unpackError = null;
 			if (needPack()) {
 				try {
 					receivePackAndCheckConnectivity();
 				} catch (IOException | RuntimeException | Error err) {
 					unpackError = err;
 				}
 			}
 
 			try {
 				if (unpackError == null) {
 					boolean atomic = isCapabilityEnabled(CAPABILITY_ATOMIC);
 					setAtomic(atomic);
 
 					validateCommands();
 					if (atomic && anyRejects()) {
 						failPendingCommands();
 					}
 
 					preReceive.onPreReceive(
 							this, filterCommands(Result.NOT_ATTEMPTED));
 					if (atomic && anyRejects()) {
 						failPendingCommands();
 					}
 					executeCommands();
 				}
 			} finally {
 				unlockPack();
 			}
 
 			if (reportStatus) {
 				sendStatusReport(true, unpackError, new Reporter() {
 					@Override
 					void sendString(String s) throws IOException {
 						pckOut.writeString(s + "\n"); //$NON-NLS-1$
 					}
 				});
 				pckOut.end();
 			} else if (msgOut != null) {
 				sendStatusReport(false, unpackError, new Reporter() {
 					@Override
 					void sendString(String s) throws IOException {
 						msgOut.write(Constants.encode(s + "\n")); //$NON-NLS-1$
 					}
 				});
 			}
 
 			if (unpackError != null) {
 				// we already know which exception to throw. Ignore
 				// potential additional exceptions raised in postReceiveHooks
 				try {
 					postReceive.onPostReceive(this, filterCommands(Result.OK));
 				} catch (Throwable e) {
 					// empty
 				}
 				throw new UnpackException(unpackError);
 			}
 			postReceive.onPostReceive(this, filterCommands(Result.OK));
 			autoGc();
 		}
 	}
 
 	private void autoGc() {
 		Repository repo = getRepository();
 		if (!repo.getConfig().getBoolean(ConfigConstants.CONFIG_RECEIVE_SECTION,
 				ConfigConstants.CONFIG_KEY_AUTOGC, true)) {
 			return;
 		}
 		repo.autoGC(NullProgressMonitor.INSTANCE);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	protected String getLockMessageProcessName() {
 		return "jgit receive-pack"; //$NON-NLS-1$
 	}
 }