"""
services/vad.py — WebRTC VAD wrapper (unchanged — already correct)
Now also used by webrtc_pipeline.py's _VADSegmenter for PCM frame processing.
"""

import webrtcvad


class VADDetector:
    def __init__(self, sample_rate=16000, frame_ms=30, aggressiveness=2):
        self.vad       = webrtcvad.Vad(aggressiveness)
        self.sample_rate = sample_rate
        self.frame_ms  = frame_ms
        self.frame_size = int(sample_rate * frame_ms / 1000) * 2

    def is_valid(self, frame: bytes) -> bool:
        return len(frame) == self.frame_size

    def is_speech(self, frame: bytes) -> bool:
        if not self.is_valid(frame):
            return False
        try:
            return self.vad.is_speech(frame, self.sample_rate)
        except Exception:
            return False


class VADSegmenter:
    def __init__(self, vad: VADDetector, silence_limit=8):
        self.vad           = vad
        self.silence_limit = silence_limit
        self.buffer        = bytearray()
        self.silence       = 0
        self.active        = False

    def add_frame(self, frame: bytes):
        speech = self.vad.is_speech(frame)

        if speech:
            self.buffer.extend(frame)
            self.active  = True
            self.silence = 0
        elif self.active:
            self.silence += 1

        if self.active and self.silence > self.silence_limit:
            audio = bytes(self.buffer)
            self.buffer.clear()
            self.silence = 0
            self.active  = False
            return audio

        return None