// Copyright 2016 The Bazel Authors. All rights reserved.
//
// 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.devtools.build.lib.sandbox;

import com.google.devtools.build.lib.runtime.CommandEnvironment;
import com.google.devtools.build.lib.shell.Command;
import com.google.devtools.build.lib.util.OsUtils;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * This runner runs process-wrapper inside a sandboxed execution root, which should work on most
 * platforms and gives at least some isolation between running actions.
 */
final class ProcessWrapperRunner extends SandboxRunner {
  private final Path execRoot;
  private final Path sandboxExecRoot;

  ProcessWrapperRunner(
      Path execRoot, Path sandboxExecRoot, boolean verboseFailures) {
    super(verboseFailures);
    this.execRoot = execRoot;
    this.sandboxExecRoot = sandboxExecRoot;
  }

  static boolean isSupported(CommandEnvironment commandEnv) {
    PathFragment embeddedTool =
        commandEnv
            .getBlazeWorkspace()
            .getBinTools()
            .getExecPath("process-wrapper" + OsUtils.executableExtension());
    if (embeddedTool == null) {
      // The embedded tool does not exist, meaning that we don't support sandboxing (e.g., while
      // bootstrapping).
      return false;
    }
    return true;
  }

  @Override
  protected Command getCommand(
      List<String> spawnArguments,
      Map<String, String> env,
      int timeout,
      boolean allowNetwork,
      boolean useFakeHostname) {
    List<String> commandLineArgs = new ArrayList<>(5 + spawnArguments.size());
    commandLineArgs.add(execRoot.getRelative("_bin/process-wrapper").getPathString());
    commandLineArgs.add(Integer.toString(timeout));
    commandLineArgs.add("5"); /* kill delay: give some time to print stacktraces and whatnot. */
    commandLineArgs.add("-"); /* stdout. */
    commandLineArgs.add("-"); /* stderr. */
    commandLineArgs.addAll(spawnArguments);

    return new Command(commandLineArgs.toArray(new String[0]), env, sandboxExecRoot.getPathFile());
  }
}