/*
 *  Copyright 2019 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#ifndef API_TEST_TIME_CONTROLLER_H_
#define API_TEST_TIME_CONTROLLER_H_

#include <memory>
#include <string>

#include "absl/strings/string_view.h"
#include "api/function_view.h"
#include "api/task_queue/task_queue_factory.h"
#include "api/units/time_delta.h"
#include "rtc_base/socket_server.h"
#include "rtc_base/thread.h"
#include "system_wrappers/include/clock.h"

namespace webrtc {
// Interface for controlling time progress. This allows us to execute test code
// in either real time or simulated time by using different implementation of
// this interface.
class TimeController {
 public:
  virtual ~TimeController() = default;
  // Provides a clock instance that follows implementation defined time
  // progress.
  virtual Clock* GetClock() = 0;
  // The returned factory will created task queues that runs in implementation
  // defined time domain.
  virtual TaskQueueFactory* GetTaskQueueFactory() = 0;
  // Simple helper to create an owned factory that can be used as a parameter
  // for PeerConnectionFactory. Note that this might depend on the underlying
  // time controller and therfore must be destroyed before the time controller
  // is destroyed.
  std::unique_ptr<TaskQueueFactory> CreateTaskQueueFactory();

  // Creates an Thread instance. If `socket_server` is nullptr, a
  // default noop socket server is created. Returned thread is not null and
  // started.
  virtual std::unique_ptr<Thread> CreateThread(
      const std::string& name,
      std::unique_ptr<SocketServer> socket_server = nullptr) = 0;

  // Creates a Thread instance that uses the provided `socket_server`.
  // The `socket_server` must outlive the returned thread.
  virtual std::unique_ptr<Thread> CreateThreadWithSocketServer(
      absl::string_view name,
      SocketServer* socket_server) = 0;

  // Creates an Thread instance that ensure that it's set as the current
  // thread.
  virtual Thread* GetMainThread() = 0;
  // Allow task queues and process threads created by this instance to execute
  // for the given `duration`.
  virtual void AdvanceTime(TimeDelta duration) = 0;

  // Waits until condition() == true, polling condition() in small time
  // intervals.
  // Returns true if condition() was evaluated to true before `max_duration`
  // elapsed and false otherwise.
  bool Wait(FunctionView<bool()> condition,
            TimeDelta max_duration = TimeDelta::Seconds(5));
};

}  // namespace webrtc
#endif  // API_TEST_TIME_CONTROLLER_H_