"""The default microphone in, the default speaker out, and two short chimes.

sounddevice (PortAudio) for both directions; MIC_DEVICE / SPEAKER_DEVICE in
.env pick something other than the system default. The chimes are made
here from sine waves — no sound files to ship.
"""

from __future__ import annotations

import array
import math
from typing import Callable, Iterable

from . import config


def open_mic(on_frame: Callable[[bytes], None]):
    """Start the microphone: 16 kHz mono int16, one 80 ms frame per call to
    *on_frame*, from PortAudio's thread. Returns the stream (stop()/close())."""
    import sounddevice as sd

    stream = sd.RawInputStream(
        samplerate=config.SAMPLE_RATE, channels=1, dtype="int16",
        blocksize=config.FRAME_SAMPLES, device=config.MIC_DEVICE,
        callback=lambda data, _frames, _time, _status: on_frame(bytes(data)),
    )
    stream.start()
    return stream


def play(chunks: Iterable[bytes], sample_rate: int = config.TTS_SAMPLE_RATE,
         should_stop: Callable[[], bool] = lambda: False) -> bool:
    """Play PCM16 mono chunks as they arrive. False if stopped early."""
    import sounddevice as sd

    with sd.RawOutputStream(samplerate=sample_rate, channels=1, dtype="int16",
                            device=config.SPEAKER_DEVICE) as out:
        for chunk in chunks:
            if should_stop():
                out.abort()
                return False
            out.write(chunk)
    return True


def tone(notes, sample_rate: int = config.TTS_SAMPLE_RATE, volume: float = 0.18) -> bytes:
    """(frequency Hz, seconds) notes as PCM16, each with a quick fade in and
    out so it doesn't click."""
    samples = array.array("h")
    for freq, seconds in notes:
        count = int(sample_rate * seconds)
        fade = max(1, int(sample_rate * 0.012))
        for i in range(count):
            envelope = min(1.0, i / fade, (count - i) / fade)
            samples.append(int(32767 * volume * envelope * math.sin(2 * math.pi * freq * i / sample_rate)))
    return samples.tobytes()


# Rising two notes: "I'm listening". Falling: "didn't work".
WAKE_CHIME = tone([(880, 0.07), (1320, 0.09)])
ERROR_CHIME = tone([(520, 0.10), (390, 0.14)])