// Copyright 2018 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.dynamic;

import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableSet;
import com.google.common.primitives.Ints;
import com.google.devtools.common.options.Converter;
import com.google.devtools.common.options.Converters;
import com.google.devtools.common.options.Option;
import com.google.devtools.common.options.OptionDocumentationCategory;
import com.google.devtools.common.options.OptionEffectTag;
import com.google.devtools.common.options.OptionsBase;
import com.google.devtools.common.options.OptionsParsingException;
import java.time.Duration;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;

/** Options related to dynamic spawn execution. */
public class DynamicExecutionOptions extends OptionsBase {

  @Option(
      name = "experimental_spawn_scheduler",
      documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
      effectTags = {OptionEffectTag.UNKNOWN},
      defaultValue = "null",
      help =
          "Enable dynamic execution by running actions locally and remotely in parallel. Bazel "
              + "spawns each action locally and remotely and picks the one that completes first. "
              + "If an action supports workers, the local action will be run in the persistent "
              + "worker mode. To enable dynamic execution for an individual action mnemonic, use "
              + "the `--internal_spawn_scheduler` and `--strategy=<mnemonic>=dynamic` flags "
              + "instead.",
      expansion = {
        "--internal_spawn_scheduler",
        "--spawn_strategy=dynamic",
      },
      deprecationWarning =
          "--experimental_spawn_scheduler is deprecated. Using dynamic execution for everything is"
              + " rarely a good idea (see https://bazel.build/remote/dynamic). If you really want"
              + " to enable dynamic execution globally, pass `--internal_spawn_scheduler "
              + "--spawn_strategy=dynamic`.")
  @Deprecated
  public Void experimentalSpawnScheduler;

  @Option(
      name = "internal_spawn_scheduler",
      documentationCategory = OptionDocumentationCategory.EXECUTION_STRATEGY,
      effectTags = {OptionEffectTag.EXECUTION, OptionEffectTag.HOST_MACHINE_RESOURCE_OPTIMIZATIONS},
      defaultValue = "false",
      help =
          "Placeholder option so that we can tell in Blaze whether the spawn scheduler was "
              + "enabled.")
  public boolean internalSpawnScheduler;

  @Option(
      name = "dynamic_local_strategy",
      converter = Converters.StringToStringListConverter.class,
      documentationCategory = OptionDocumentationCategory.EXECUTION_STRATEGY,
      effectTags = {OptionEffectTag.EXECUTION, OptionEffectTag.HOST_MACHINE_RESOURCE_OPTIMIZATIONS},
      defaultValue = "null",
      allowMultiple = true,
      help =
          "The local strategies, in order, to use for the given mnemonic - the first applicable "
              + "strategy is used. For example, `worker,sandboxed` runs actions that support "
              + "persistent workers using the worker strategy, and all others using the sandboxed "
              + "strategy. If no mnemonic is given, the list of strategies is used as the "
              + "fallback for all mnemonics. The default fallback list is `worker,sandboxed`, or"
              + "`worker,sandboxed,standalone` if `experimental_local_lockfree_output` is set. "
              + "Takes [mnemonic=]local_strategy[,local_strategy,...]")
  public List<Map.Entry<String, List<String>>> dynamicLocalStrategy;

  @Option(
      name = "dynamic_remote_strategy",
      converter = Converters.StringToStringListConverter.class,
      documentationCategory = OptionDocumentationCategory.EXECUTION_STRATEGY,
      effectTags = {OptionEffectTag.EXECUTION, OptionEffectTag.HOST_MACHINE_RESOURCE_OPTIMIZATIONS},
      defaultValue = "null",
      allowMultiple = true,
      help =
          "The remote strategies, in order, to use for the given mnemonic - the first applicable "
              + "strategy is used. If no mnemonic is given, the list of strategies is used as the "
              + "fallback for all mnemonics. The default fallback list is `remote`, so this flag "
              + "usually does not need to be set explicitly. "
              + "Takes [mnemonic=]remote_strategy[,remote_strategy,...]")
  public List<Map.Entry<String, List<String>>> dynamicRemoteStrategy;

  @Option(
      name = "dynamic_local_execution_delay",
      oldName = "experimental_local_execution_delay",
      oldNameWarning = false,
      documentationCategory = OptionDocumentationCategory.EXECUTION_STRATEGY,
      effectTags = {OptionEffectTag.EXECUTION, OptionEffectTag.HOST_MACHINE_RESOURCE_OPTIMIZATIONS},
      defaultValue = "1000",
      help =
          "How many milliseconds should local execution be delayed, if remote execution was faster"
              + " during a build at least once?")
  public int localExecutionDelay;

  @Option(
      name = "debug_spawn_scheduler",
      oldName = "experimental_debug_spawn_scheduler",
      oldNameWarning = false,
      documentationCategory = OptionDocumentationCategory.LOGGING,
      effectTags = {OptionEffectTag.UNKNOWN},
      defaultValue = "false")
  public boolean debugSpawnScheduler;

  @Option(
      name = "experimental_dynamic_slow_remote_time",
      documentationCategory = OptionDocumentationCategory.EXECUTION_STRATEGY,
      effectTags = {OptionEffectTag.EXECUTION, OptionEffectTag.HOST_MACHINE_RESOURCE_OPTIMIZATIONS},
      defaultValue = "0",
      help =
          "If >0, the time a dynamically run action must run remote-only before we"
              + " prioritize its local execution to avoid remote timeouts."
              + " This may hide some problems on the remote execution system. Do not turn this on"
              + " without monitoring of remote execution issues.")
  public Duration slowRemoteTime;

  @Option(
      name = "experimental_dynamic_local_load_factor",
      documentationCategory = OptionDocumentationCategory.EXECUTION_STRATEGY,
      effectTags = {OptionEffectTag.EXECUTION, OptionEffectTag.HOST_MACHINE_RESOURCE_OPTIMIZATIONS},
      defaultValue = "0",
      help =
          "Controls how much load from dynamic execution to put on the local machine."
              + " This flag adjusts how many actions in dynamic execution we will schedule"
              + " concurrently. It is based on the number of CPUs Blaze thinks is available,"
              + " which can be controlled with the --local_cpu_resources flag."
              + "\nIf this flag is 0, all actions are scheduled locally immediately. If > 0,"
              + " the amount of actions scheduled locally is limited by the number of CPUs"
              + " available. If < 1, the load factor is used to reduce the number of locally"
              + " scheduled actions when the number of actions waiting to schedule is high."
              + " This lessens the load on the local machine in the clean build case, where"
              + " the local machine does not contribute much.")
  public double localLoadFactor;

  @Option(
      name = "experimental_dynamic_exclude_tools",
      documentationCategory = OptionDocumentationCategory.EXECUTION_STRATEGY,
      effectTags = {OptionEffectTag.EXECUTION, OptionEffectTag.HOST_MACHINE_RESOURCE_OPTIMIZATIONS},
      defaultValue = "true",
      help =
          "When set, targets that are build \"for tool\" are not subject to dynamic execution. Such"
              + " targets are extremely unlikely to be built incrementally and thus not worth"
              + " spending local cycles on.")
  public boolean excludeTools;

  @Option(
      name = "experimental_dynamic_ignore_local_signals",
      documentationCategory = OptionDocumentationCategory.BUILD_TIME_OPTIMIZATION,
      converter = SignalListConverter.class,
      effectTags = {OptionEffectTag.EXECUTION},
      defaultValue = "null",
      help =
          "Takes a list of OS signal numbers. If a local branch of dynamic execution"
              + " gets killed with any of these signals, the remote branch will be allowed to"
              + " finish instead. For persistent workers, this only affects signals that kill"
              + " the worker process.")
  public Set<Integer> ignoreLocalSignals;

  /** Converts comma-separated lists of signal numbers into a set of signal numbers. */
  public static class SignalListConverter implements Converter<Set<Integer>> {
    @Override
    public ImmutableSet<Integer> convert(String input, @Nullable Object conversionContext)
        throws OptionsParsingException {
      if (input == null || "null".equals(input)) {
        return ImmutableSet.of();
      }
      Iterable<String> parts = Splitter.on(",").split(input);
      if (!parts.iterator().hasNext()) {
        throw new OptionsParsingException("Requires at least one signal number");
      }
      ImmutableSet.Builder<Integer> signals = new ImmutableSet.Builder<>();
      for (String p : parts) {
        String trimmed = p.trim();
        Integer signalNum = Ints.tryParse(trimmed);
        if (signalNum != null && signalNum > 0) {
          signals.add(signalNum);
        } else {
          throw new OptionsParsingException(String.format("No such signal %s", trimmed));
        }
      }
      return signals.build();
    }

    @Override
    public String getTypeDescription() {
      return "a comma-separated list of signal numbers";
    }
  }
}