# -*- coding: utf-8 -*-
"""
AudioRecorder – minimaler Recorder mit sounddevice (16kHz mono WAV).
"""

import os
import tempfile
import wave


class AudioRecorder:
    """
    Minimaler Recorder mit sounddevice.
    Speichert als 16kHz mono WAV (16-bit PCM).
    """
    def __init__(self, samplerate=16000, channels=1):
        self.samplerate = samplerate
        self.channels = channels
        self._stream = None
        self._frames = []
        self._recording = False

    def start(self):
        try:
            import sounddevice as sd
        except Exception as e:
            raise RuntimeError(
                "Python-Paket 'sounddevice' fehlt.\n\n"
                "Installiere es mit:\n"
                "  py -3.11 -m pip install sounddevice\n\n"
                f"Details: {e}"
            )

        self._frames = []
        self._recording = True

        def callback(indata, frames, time_info, status):
            if self._recording:
                self._frames.append(indata.copy())

        self._stream = sd.InputStream(
            samplerate=self.samplerate,
            channels=self.channels,
            callback=callback,
            dtype="float32",
            blocksize=0,
        )
        self._stream.start()

    def stop_and_save_wav(self) -> str:
        if not self._stream:
            raise RuntimeError("Recorder wurde nicht gestartet.")
        self._recording = False
        self._stream.stop()
        self._stream.close()
        self._stream = None

        if not self._frames:
            raise RuntimeError("Keine Audio-Daten aufgenommen (leer).")

        import numpy as np
        audio = np.concatenate(self._frames, axis=0)
        audio = np.clip(audio, -1.0, 1.0)
        pcm16 = (audio * 32767.0).astype(np.int16)

        fd, path = tempfile.mkstemp(suffix=".wav", prefix="kg_rec_")
        os.close(fd)
        with wave.open(path, "wb") as wf:
            wf.setnchannels(self.channels)
            wf.setsampwidth(2)
            wf.setframerate(self.samplerate)
            wf.writeframes(pcm16.tobytes())

        return path