from __future__ import annotations


class AudioPacer:
    def __init__(self, *, frame_bytes: int) -> None:
        self._frame_bytes = max(int(frame_bytes), 1)
        self._buffer = bytearray()

    @property
    def buffered_bytes(self) -> int:
        return len(self._buffer)

    def push(self, audio_chunk: bytes) -> list[bytes]:
        if not audio_chunk:
            return []
        self._buffer.extend(audio_chunk)
        return self._pop_frames()

    def flush(self, *, pad_final_frame: bool = True) -> list[bytes]:
        frames = self._pop_frames()
        if not self._buffer:
            return frames
        if pad_final_frame:
            padded = bytes(self._buffer) + (b"\x00" * (self._frame_bytes - len(self._buffer)))
            frames.append(padded)
        else:
            frames.append(bytes(self._buffer))
        self._buffer.clear()
        return frames

    def clear(self) -> None:
        self._buffer.clear()

    def reset(self) -> None:
        self.clear()

    def _pop_frames(self) -> list[bytes]:
        frames: list[bytes] = []
        while len(self._buffer) >= self._frame_bytes:
            frames.append(bytes(self._buffer[: self._frame_bytes]))
            del self._buffer[: self._frame_bytes]
        return frames