// Copyright (C) 2008 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.gerrit.sshd.commands;

import com.google.common.collect.Lists;
import com.google.gerrit.extensions.registration.DynamicSet;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.server.RequestInfo;
import com.google.gerrit.server.RequestListener;
import com.google.gerrit.server.git.DefaultAdvertiseRefsHook;
import com.google.gerrit.server.git.TransferConfig;
import com.google.gerrit.server.git.UploadPackInitializer;
import com.google.gerrit.server.git.validators.UploadValidationException;
import com.google.gerrit.server.git.validators.UploadValidators;
import com.google.gerrit.server.logging.TraceContext;
import com.google.gerrit.server.permissions.PermissionBackend;
import com.google.gerrit.server.permissions.PermissionBackend.RefFilterOptions;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.gerrit.server.permissions.ProjectPermission;
import com.google.gerrit.server.plugincontext.PluginSetContext;
import com.google.gerrit.sshd.AbstractGitCommand;
import com.google.gerrit.sshd.SshSession;
import com.google.inject.Inject;
import java.io.IOException;
import java.util.List;
import org.eclipse.jgit.transport.PostUploadHook;
import org.eclipse.jgit.transport.PostUploadHookChain;
import org.eclipse.jgit.transport.PreUploadHook;
import org.eclipse.jgit.transport.PreUploadHookChain;
import org.eclipse.jgit.transport.UploadPack;

/** Publishes Git repositories over SSH using the Git upload-pack protocol. */
final class Upload extends AbstractGitCommand {
  @Inject private TransferConfig config;
  @Inject private DynamicSet<PreUploadHook> preUploadHooks;
  @Inject private DynamicSet<PostUploadHook> postUploadHooks;
  @Inject private DynamicSet<UploadPackInitializer> uploadPackInitializers;
  @Inject private PluginSetContext<RequestListener> requestListeners;
  @Inject private UploadValidators.Factory uploadValidatorsFactory;
  @Inject private SshSession session;
  @Inject private PermissionBackend permissionBackend;

  @Override
  protected void runImpl() throws IOException, Failure {
    PermissionBackend.ForProject perm =
        permissionBackend.user(user).project(projectState.getNameKey());
    try {

      perm.check(ProjectPermission.RUN_UPLOAD_PACK);
    } catch (AuthException e) {
      throw new Failure(1, "fatal: upload-pack not permitted on this server");
    } catch (PermissionBackendException e) {
      throw new Failure(1, "fatal: unable to check permissions " + e);
    }

    final UploadPack up = new UploadPack(repo);
    up.setAdvertiseRefsHook(new DefaultAdvertiseRefsHook(perm, RefFilterOptions.defaults()));
    up.setPackConfig(config.getPackConfig());
    up.setTimeout(config.getTimeout());
    up.setPostUploadHook(PostUploadHookChain.newChain(Lists.newArrayList(postUploadHooks)));

    List<PreUploadHook> allPreUploadHooks = Lists.newArrayList(preUploadHooks);
    allPreUploadHooks.add(
        uploadValidatorsFactory.create(project, repo, session.getRemoteAddressAsString()));
    up.setPreUploadHook(PreUploadHookChain.newChain(allPreUploadHooks));
    for (UploadPackInitializer initializer : uploadPackInitializers) {
      initializer.init(projectState.getNameKey(), up);
    }
    try (TraceContext traceContext = TraceContext.open()) {
      RequestInfo requestInfo =
          RequestInfo.builder(RequestInfo.RequestType.GIT_UPLOAD, user, traceContext)
              .project(projectState.getNameKey())
              .build();
      requestListeners.runEach(l -> l.onRequest(requestInfo));

      up.upload(in, out, err);
      session.setPeerAgent(up.getPeerUserAgent());
    } catch (UploadValidationException e) {
      // UploadValidationException is used by the UploadValidators to
      // stop the uploadPack. We do not want this exception to go beyond this
      // point otherwise it would print a stacktrace in the logs and return an
      // internal server error to the client.
      if (!e.isOutput()) {
        up.sendMessage(e.getMessage());
      }
    }
  }
}