/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

#include "Task.h"
#include <atomic>

namespace facebook::react {

namespace {

inline uint64_t getNextId() noexcept {
  static std::atomic<uint64_t> nextId = 1;
  return nextId++;
}

} // namespace

Task::Task(
    SchedulerPriority priority,
    jsi::Function&& callback,
    HighResTimeStamp expirationTime)
    : priority(priority),
      callback(std::move(callback)),
      expirationTime(expirationTime),
      id(getNextId()) {}

Task::Task(
    SchedulerPriority priority,
    RawCallback&& callback,
    HighResTimeStamp expirationTime)
    : priority(priority),
      callback(std::move(callback)),
      expirationTime(expirationTime),
      id(getNextId()) {}

jsi::Value Task::execute(jsi::Runtime& runtime, bool didUserCallbackTimeout) {
  auto result = jsi::Value::undefined();
  // Canceled task doesn't have a callback.
  if (!callback) {
    return result;
  }

  // We get the value of the callback and reset it immediately to avoid it being
  // called more than once (including when the callback throws).
  auto originalCallback = std::move(*callback);
  callback.reset();

  if (originalCallback.index() == 0) {
    // Callback in JavaScript is expecting a single bool parameter.
    // React team plans to remove it in the future when a scheduler bug on web
    // is resolved.
    result = std::get<jsi::Function>(originalCallback)
                 .call(runtime, {didUserCallbackTimeout});
  } else {
    // Calling a raw callback
    std::get<RawCallback>(originalCallback)(runtime);
  }

  return result;
}

} // namespace facebook::react