/*
 * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
 * 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 static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_ATOMIC;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.MessageFormat;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.eclipse.jgit.errors.NoRemoteRepositoryException;
import org.eclipse.jgit.errors.NotSupportedException;
import org.eclipse.jgit.errors.PackProtocolException;
import org.eclipse.jgit.errors.TooLargeObjectInPackException;
import org.eclipse.jgit.errors.TooLargePackException;
import org.eclipse.jgit.errors.TransportException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.internal.storage.pack.PackWriter;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ProgressMonitor;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.transport.RemoteRefUpdate.Status;

Push implementation using the native Git pack transfer service.

This is the canonical implementation for transferring objects to the remote
repository from the local repository by talking to the 'git-receive-pack'
service. Objects are packed on the local side into a pack file and then sent
to the remote repository.

This connection requires only a bi-directional pipe or socket, and thus is
easily wrapped up into a local process pipe, anonymous TCP socket, or a
command executed through an SSH tunnel.
 This implementation honors Transport.isPushThin() option. 
 Concrete implementations should just call BasePackConnection.init(InputStream, OutputStream) and BasePackConnection.readAdvertisedRefs() methods in constructor or before any use. They should also handle resources releasing in BasePackConnection.close() method if needed. /**
 * Push implementation using the native Git pack transfer service.
 * <p>
 * This is the canonical implementation for transferring objects to the remote
 * repository from the local repository by talking to the 'git-receive-pack'
 * service. Objects are packed on the local side into a pack file and then sent
 * to the remote repository.
 * <p>
 * This connection requires only a bi-directional pipe or socket, and thus is
 * easily wrapped up into a local process pipe, anonymous TCP socket, or a
 * command executed through an SSH tunnel.
 * <p>
 * This implementation honors
 * {@link org.eclipse.jgit.transport.Transport#isPushThin()} option.
 * <p>
 * Concrete implementations should just call
 * {@link #init(java.io.InputStream, java.io.OutputStream)} and
 * {@link #readAdvertisedRefs()} methods in constructor or before any use. They
 * should also handle resources releasing in {@link #close()} method if needed.
 */
public abstract class BasePackPushConnection extends BasePackConnection implements
		PushConnection {
	
The client expects a status report after the server processes the pack.
Since:
2.0/**
	 * The client expects a status report after the server processes the pack.
	 * @since 2.0
	 */
	public static final String CAPABILITY_REPORT_STATUS = GitProtocolConstants.CAPABILITY_REPORT_STATUS;

	
The server supports deleting refs.
Since:
2.0/**
	 * The server supports deleting refs.
	 * @since 2.0
	 */
	public static final String CAPABILITY_DELETE_REFS = GitProtocolConstants.CAPABILITY_DELETE_REFS;

	
The server supports packs with OFS deltas.
Since:
2.0/**
	 * The server supports packs with OFS deltas.
	 * @since 2.0
	 */
	public static final String CAPABILITY_OFS_DELTA = GitProtocolConstants.CAPABILITY_OFS_DELTA;

	
The client supports using the 64K side-band for progress messages.
Since:
2.0/**
	 * The client supports using the 64K side-band for progress messages.
	 * @since 2.0
	 */
	public static final String CAPABILITY_SIDE_BAND_64K = GitProtocolConstants.CAPABILITY_SIDE_BAND_64K;

	
The server supports the receiving of push options.
Since:
4.5/**
	 * The server supports the receiving of push options.
	 * @since 4.5
	 */
	public static final String CAPABILITY_PUSH_OPTIONS = GitProtocolConstants.CAPABILITY_PUSH_OPTIONS;

	private final boolean thinPack;
	private final boolean atomic;

	
A list of option strings associated with this push. /** A list of option strings associated with this push. */
	private List<String> pushOptions;

	private boolean capableAtomic;
	private boolean capableDeleteRefs;
	private boolean capableReport;
	private boolean capableSideBand;
	private boolean capableOfsDelta;
	private boolean capablePushOptions;

	private boolean sentCommand;
	private boolean writePack;

	
Time in milliseconds spent transferring the pack data. /** Time in milliseconds spent transferring the pack data. */
	private long packTransferTime;

	
Create a new connection to push using the native git transport.
Params:
packTransport – 
           the transport./**
	 * Create a new connection to push using the native git transport.
	 *
	 * @param packTransport
	 *            the transport.
	 */
	public BasePackPushConnection(PackTransport packTransport) {
		super(packTransport);
		thinPack = transport.isPushThin();
		atomic = transport.isPushAtomic();
		pushOptions = transport.getPushOptions();
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	public void push(final ProgressMonitor monitor,
			final Map<String, RemoteRefUpdate> refUpdates)
			throws TransportException {
		push(monitor, refUpdates, null);
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	public void push(final ProgressMonitor monitor,
			final Map<String, RemoteRefUpdate> refUpdates, OutputStream outputStream)
			throws TransportException {
		markStartedOperation();
		doPush(monitor, refUpdates, outputStream);
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	protected TransportException noRepository() {
		// Sadly we cannot tell the "invalid URI" case from "push not allowed".
		// Opening a fetch connection can help us tell the difference, as any
		// useful repository is going to support fetch if it also would allow
		// push. So if fetch throws NoRemoteRepositoryException we know the
		// URI is wrong. Otherwise we can correctly state push isn't allowed
		// as the fetch connection opened successfully.
		//
		try {
			transport.openFetch().close();
		} catch (NotSupportedException e) {
			// Fall through.
		} catch (NoRemoteRepositoryException e) {
			// Fetch concluded the repository doesn't exist.
			//
			return e;
		} catch (TransportException e) {
			// Fall through.
		}
		return new TransportException(uri, JGitText.get().pushNotPermitted);
	}

	
Push one or more objects and update the remote repository.
Params:
monitor – 
           progress monitor to receive status updates.
refUpdates – 
           update commands to be applied to the remote repository.
outputStream – 
           output stream to write sideband messages to
Throws:
TransportException – 
            if any exception occurs.
Since:
3.0/**
	 * Push one or more objects and update the remote repository.
	 *
	 * @param monitor
	 *            progress monitor to receive status updates.
	 * @param refUpdates
	 *            update commands to be applied to the remote repository.
	 * @param outputStream
	 *            output stream to write sideband messages to
	 * @throws org.eclipse.jgit.errors.TransportException
	 *             if any exception occurs.
	 * @since 3.0
	 */
	protected void doPush(final ProgressMonitor monitor,
			final Map<String, RemoteRefUpdate> refUpdates,
			OutputStream outputStream) throws TransportException {
		try {
			writeCommands(refUpdates.values(), monitor, outputStream);

			if (pushOptions != null && capablePushOptions)
				transmitOptions();
			if (writePack)
				writePack(refUpdates, monitor);
			if (sentCommand) {
				if (capableReport)
					readStatusReport(refUpdates);
				if (capableSideBand) {
					// Ensure the data channel is at EOF, so we know we have
					// read all side-band data from all channels and have a
					// complete copy of the messages (if any) buffered from
					// the other data channels.
					//
					int b = in.read();
					if (0 <= b)
						throw new TransportException(uri, MessageFormat.format(
								JGitText.get().expectedEOFReceived,
								Character.valueOf((char) b)));
				}
			}
		} catch (TransportException e) {
			throw e;
		} catch (Exception e) {
			throw new TransportException(uri, e.getMessage(), e);
		} finally {
			close();
		}
	}

	private void writeCommands(final Collection<RemoteRefUpdate> refUpdates,
			final ProgressMonitor monitor, OutputStream outputStream) throws IOException {
		final String capabilities = enableCapabilities(monitor, outputStream);
		if (atomic && !capableAtomic) {
			throw new TransportException(uri,
					JGitText.get().atomicPushNotSupported);
		}

		if (pushOptions != null && !capablePushOptions) {
			throw new TransportException(uri,
					MessageFormat.format(JGitText.get().pushOptionsNotSupported,
							pushOptions.toString()));
		}

		for (RemoteRefUpdate rru : refUpdates) {
			if (!capableDeleteRefs && rru.isDelete()) {
				rru.setStatus(Status.REJECTED_NODELETE);
				continue;
			}

			final StringBuilder sb = new StringBuilder();
			ObjectId oldId = rru.getExpectedOldObjectId();
			if (oldId == null) {
				final Ref advertised = getRef(rru.getRemoteName());
				oldId = advertised != null ? advertised.getObjectId() : null;
				if (oldId == null) {
					oldId = ObjectId.zeroId();
				}
			}
			sb.append(oldId.name());
			sb.append(' ');
			sb.append(rru.getNewObjectId().name());
			sb.append(' ');
			sb.append(rru.getRemoteName());
			if (!sentCommand) {
				sentCommand = true;
				sb.append(capabilities);
			}

			pckOut.writeString(sb.toString());
			rru.setStatus(Status.AWAITING_REPORT);
			if (!rru.isDelete())
				writePack = true;
		}

		if (monitor.isCancelled())
			throw new TransportException(uri, JGitText.get().pushCancelled);
		pckOut.end();
		outNeedsEnd = false;
	}

	private void transmitOptions() throws IOException {
		for (String pushOption : pushOptions) {
			pckOut.writeString(pushOption);
		}

		pckOut.end();
	}

	private String enableCapabilities(final ProgressMonitor monitor,
			OutputStream outputStream) {
		final StringBuilder line = new StringBuilder();
		if (atomic)
			capableAtomic = wantCapability(line, CAPABILITY_ATOMIC);
		capableReport = wantCapability(line, CAPABILITY_REPORT_STATUS);
		capableDeleteRefs = wantCapability(line, CAPABILITY_DELETE_REFS);
		capableOfsDelta = wantCapability(line, CAPABILITY_OFS_DELTA);

		if (pushOptions != null) {
			capablePushOptions = wantCapability(line, CAPABILITY_PUSH_OPTIONS);
		}

		capableSideBand = wantCapability(line, CAPABILITY_SIDE_BAND_64K);
		if (capableSideBand) {
			in = new SideBandInputStream(in, monitor, getMessageWriter(),
					outputStream);
			pckIn = new PacketLineIn(in);
		}
		addUserAgentCapability(line);

		if (line.length() > 0)
			line.setCharAt(0, '\0');
		return line.toString();
	}

	private void writePack(final Map<String, RemoteRefUpdate> refUpdates,
			final ProgressMonitor monitor) throws IOException {
		Set<ObjectId> remoteObjects = new HashSet<>();
		Set<ObjectId> newObjects = new HashSet<>();

		try (PackWriter writer = new PackWriter(transport.getPackConfig(),
				local.newObjectReader())) {

			for (Ref r : getRefs()) {
				// only add objects that we actually have
				ObjectId oid = r.getObjectId();
				if (local.getObjectDatabase().has(oid))
					remoteObjects.add(oid);
			}
			remoteObjects.addAll(additionalHaves);
			for (RemoteRefUpdate r : refUpdates.values()) {
				if (!ObjectId.zeroId().equals(r.getNewObjectId()))
					newObjects.add(r.getNewObjectId());
			}

			writer.setIndexDisabled(true);
			writer.setUseCachedPacks(true);
			writer.setUseBitmaps(true);
			writer.setThin(thinPack);
			writer.setReuseValidatingObjects(false);
			writer.setDeltaBaseAsOffset(capableOfsDelta);
			writer.preparePack(monitor, newObjects, remoteObjects);

			OutputStream packOut = out;
			if (capableSideBand) {
				packOut = new CheckingSideBandOutputStream(in, out);
			}
			writer.writePack(monitor, monitor, packOut);

			packTransferTime = writer.getStatistics().getTimeWriting();
		}
	}

	private void readStatusReport(Map<String, RemoteRefUpdate> refUpdates)
			throws IOException {
		final String unpackLine = readStringLongTimeout();
		if (!unpackLine.startsWith("unpack ")) //$NON-NLS-1$
			throw new PackProtocolException(uri, MessageFormat
					.format(JGitText.get().unexpectedReportLine, unpackLine));
		final String unpackStatus = unpackLine.substring("unpack ".length()); //$NON-NLS-1$
		if (unpackStatus.startsWith("error Pack exceeds the limit of")) {//$NON-NLS-1$
			throw new TooLargePackException(uri,
					unpackStatus.substring("error ".length())); //$NON-NLS-1$
		} else if (unpackStatus.startsWith("error Object too large")) {//$NON-NLS-1$
			throw new TooLargeObjectInPackException(uri,
					unpackStatus.substring("error ".length())); //$NON-NLS-1$
		} else if (!unpackStatus.equals("ok")) { //$NON-NLS-1$
			throw new TransportException(uri, MessageFormat.format(
					JGitText.get().errorOccurredDuringUnpackingOnTheRemoteEnd, unpackStatus));
		}

		for (String refLine : pckIn.readStrings()) {
			boolean ok = false;
			int refNameEnd = -1;
			if (refLine.startsWith("ok ")) { //$NON-NLS-1$
				ok = true;
				refNameEnd = refLine.length();
			} else if (refLine.startsWith("ng ")) { //$NON-NLS-1$
				ok = false;
				refNameEnd = refLine.indexOf(" ", 3); //$NON-NLS-1$
			}
			if (refNameEnd == -1)
				throw new PackProtocolException(MessageFormat.format(JGitText.get().unexpectedReportLine2
						, uri, refLine));
			final String refName = refLine.substring(3, refNameEnd);
			final String message = (ok ? null : refLine
					.substring(refNameEnd + 1));

			final RemoteRefUpdate rru = refUpdates.get(refName);
			if (rru == null)
				throw new PackProtocolException(MessageFormat.format(JGitText.get().unexpectedRefReport, uri, refName));
			if (ok) {
				rru.setStatus(Status.OK);
			} else {
				rru.setStatus(Status.REJECTED_OTHER_REASON);
				rru.setMessage(message);
			}
		}
		for (RemoteRefUpdate rru : refUpdates.values()) {
			if (rru.getStatus() == Status.AWAITING_REPORT)
				throw new PackProtocolException(MessageFormat.format(
						JGitText.get().expectedReportForRefNotReceived , uri, rru.getRemoteName()));
		}
	}

	private String readStringLongTimeout() throws IOException {
		if (timeoutIn == null)
			return pckIn.readString();

		// The remote side may need a lot of time to choke down the pack
		// we just sent them. There may be many deltas that need to be
		// resolved by the remote. Its hard to say how long the other
		// end is going to be silent. Taking 10x the configured timeout
		// or the time spent transferring the pack, whichever is larger,
		// gives the other side some reasonable window to process the data,
		// but this is just a wild guess.
		//
		final int oldTimeout = timeoutIn.getTimeout();
		final int sendTime = (int) Math.min(packTransferTime, 28800000L);
		try {
			int timeout = 10 * Math.max(sendTime, oldTimeout);
			timeoutIn.setTimeout((timeout < 0) ? Integer.MAX_VALUE : timeout);
			return pckIn.readString();
		} finally {
			timeoutIn.setTimeout(oldTimeout);
		}
	}

	
Gets the list of option strings associated with this push.
Returns:
pushOptions
Since:
4.5/**
	 * Gets the list of option strings associated with this push.
	 *
	 * @return pushOptions
	 * @since 4.5
	 */
	public List<String> getPushOptions() {
		return pushOptions;
	}

	private static class CheckingSideBandOutputStream extends OutputStream {
		private final InputStream in;
		private final OutputStream out;

		CheckingSideBandOutputStream(InputStream in, OutputStream out) {
			this.in = in;
			this.out = out;
		}

		@Override
		public void write(int b) throws IOException {
			write(new byte[] { (byte) b });
		}

		@Override
		public void write(byte[] buf, int ptr, int cnt) throws IOException {
			try {
				out.write(buf, ptr, cnt);
			} catch (IOException e) {
				throw checkError(e);
			}
		}

		@Override
		public void flush() throws IOException {
			try {
				out.flush();
			} catch (IOException e) {
				throw checkError(e);
			}
		}

		private IOException checkError(IOException e1) {
			try {
				in.read();
			} catch (TransportException e2) {
				return e2;
			} catch (IOException e2) {
				return e1;
			}
			return e1;
		}
	}
}