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#ifndef CONTENT_BROWSER_SPEECH_ENDPOINTER_ENDPOINTER_H_

#define CONTENT_BROWSER_SPEECH_ENDPOINTER_ENDPOINTER_H_

#include "energy_endpointer.h"

namespace mozilla {

struct AudioChunk;

// A simple interface to the underlying energy-endpointer implementation, this

// class lets callers provide audio as being recorded and let them poll to find

// when the user has stopped speaking.

//

// There are two events that may trigger the end of speech:

//

// speechInputPossiblyComplete event:

//

// Signals that silence/noise has  been detected for a *short* amount of

// time after some speech has been detected. It can be used for low latency

// UI feedback. To disable it, set it to a large amount.

//

// speechInputComplete event:

//

// This event is intended to signal end of input and to stop recording.

// The amount of time to wait after speech is set by

// speech_input_complete_silence_length_ and optionally two other

// parameters (see below).

// This time can be held constant, or can change as more speech is detected.

// In the latter case, the time changes after a set amount of time from the

// *beginning* of speech.  This is motivated by the expectation that there

// will be two distinct types of inputs: short search queries and longer

// dictation style input.

//

// Three parameters are used to define the piecewise constant timeout function.

// The timeout length is speech_input_complete_silence_length until

// long_speech_length, when it changes to

// long_speech_input_complete_silence_length.

class Endpointer {

 public:

  explicit Endpointer(int sample_rate);

  // Start the endpointer. This should be called at the beginning of a session.

  void StartSession();

  // Stop the endpointer.

  void EndSession();

  // Start environment estimation. Audio will be used for environment estimation

  // i.e. noise level estimation.

  void SetEnvironmentEstimationMode();

  // Start user input. This should be called when the user indicates start of

  // input, e.g. by pressing a button.

  void SetUserInputMode();

  // Process a segment of audio, which may be more than one frame.

  // The status of the last frame will be returned.

  EpStatus ProcessAudio(const AudioChunk& raw_audio, float* rms_out);

  // Get the status of the endpointer.

  EpStatus Status(int64_t *time_us);

  // Get the expected frame size for audio chunks. Audio chunks are expected

  // to contain a number of samples that is a multiple of this number, and extra

  // samples will be dropped.

  int32_t FrameSize() const {

    return frame_size_;

  }

  // Returns true if the endpointer detected reasonable audio levels above

  // background noise which could be user speech, false if not.

  bool DidStartReceivingSpeech() const {

    return speech_previously_detected_;

  }

  bool IsEstimatingEnvironment() const {

    return energy_endpointer_.estimating_environment();

  }

  void set_speech_input_complete_silence_length(int64_t time_us) {

    speech_input_complete_silence_length_us_ = time_us;

  }

  void set_long_speech_input_complete_silence_length(int64_t time_us) {

    long_speech_input_complete_silence_length_us_ = time_us;

  }

  void set_speech_input_possibly_complete_silence_length(int64_t time_us) {

    speech_input_possibly_complete_silence_length_us_ = time_us;

  }

  void set_long_speech_length(int64_t time_us) {

    long_speech_length_us_ = time_us;

  }

  bool speech_input_complete() const {

    return speech_input_complete_;

  }

  // RMS background noise level in dB.

  float NoiseLevelDb() const { return energy_endpointer_.GetNoiseLevelDb(); }

 private:

  // Reset internal states. Helper method common to initial input utterance

  // and following input utternaces.

  void Reset();

  // Minimum allowable length of speech input.

  int64_t speech_input_minimum_length_us_;

  // The speechInputPossiblyComplete event signals that silence/noise has been

  // detected for a *short* amount of time after some speech has been detected.

  // This proporty specifies the time period.

  int64_t speech_input_possibly_complete_silence_length_us_;

  // The speechInputComplete event signals that silence/noise has been

  // detected for a *long* amount of time after some speech has been detected.

  // This property specifies the time period.

  int64_t speech_input_complete_silence_length_us_;

  // Same as above, this specifies the required silence period after speech

  // detection. This period is used instead of

  // speech_input_complete_silence_length_ when the utterance is longer than

  // long_speech_length_. This parameter is optional.

  int64_t long_speech_input_complete_silence_length_us_;

  // The period of time after which the endpointer should consider

  // long_speech_input_complete_silence_length_ as a valid silence period

  // instead of speech_input_complete_silence_length_. This parameter is

  // optional.

  int64_t long_speech_length_us_;

  // First speech onset time, used in determination of speech complete timeout.

  int64_t speech_start_time_us_;

  // Most recent end time, used in determination of speech complete timeout.

  int64_t speech_end_time_us_;

  int64_t audio_frame_time_us_;

  EpStatus old_ep_status_;

  bool waiting_for_speech_possibly_complete_timeout_;

  bool waiting_for_speech_complete_timeout_;

  bool speech_previously_detected_;

  bool speech_input_complete_;

  EnergyEndpointer energy_endpointer_;

  int sample_rate_;

  int32_t frame_size_;

};

}  // namespace mozilla

#endif  // CONTENT_BROWSER_SPEECH_ENDPOINTER_ENDPOINTER_H_