// Copyright 2015 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.common.collect.ImmutableList;
import com.google.devtools.build.lib.actions.Executor.ActionContext;
import com.google.devtools.build.lib.buildtool.BuildRequest;
import com.google.devtools.build.lib.exec.ActionContextProvider;
import com.google.devtools.build.lib.exec.ExecutionOptions;
import com.google.devtools.build.lib.runtime.CommandEnvironment;
import com.google.devtools.build.lib.util.OS;
import com.google.devtools.build.lib.vfs.Path;
import java.io.IOException;

/**
 * Provides the sandboxed spawn strategy.
 */
final class SandboxActionContextProvider extends ActionContextProvider {

  @SuppressWarnings("unchecked")
  private final ImmutableList<ActionContext> contexts;

  private SandboxActionContextProvider(ImmutableList<ActionContext> contexts) {
    this.contexts = contexts;
  }

  public static SandboxActionContextProvider create(
      CommandEnvironment cmdEnv, BuildRequest buildRequest, Path sandboxBase) throws IOException {
    ImmutableList.Builder<ActionContext> contexts = ImmutableList.builder();

    boolean verboseFailures = buildRequest.getOptions(ExecutionOptions.class).verboseFailures;
    String productName = cmdEnv.getRuntime().getProductName();

    // The ProcessWrapperSandboxedStrategy works on all POSIX-compatible operating systems.
    if (OS.isPosixCompatible()) {
      contexts.add(
          new ProcessWrapperSandboxedStrategy(
              cmdEnv, buildRequest, sandboxBase, verboseFailures, productName));
    }

    switch (OS.getCurrent()) {
      case LINUX:
        if (LinuxSandboxedStrategy.isSupported(cmdEnv)) {
          contexts.add(
              LinuxSandboxedStrategy.create(cmdEnv, buildRequest, sandboxBase, verboseFailures));
        }
        break;
      case DARWIN:
        if (DarwinSandboxRunner.isSupported(cmdEnv)) {
          contexts.add(
              DarwinSandboxedStrategy.create(
                  cmdEnv, buildRequest, sandboxBase, verboseFailures, productName));
        }
        break;
      default:
        // No additional platform-specific sandboxing available.
    }

    return new SandboxActionContextProvider(contexts.build());
  }

  @Override
  public Iterable<ActionContext> getActionContexts() {
    return contexts;
  }
}