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#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "mlx-whisper",
#     "pyannote.audio",
#     "torch",
#     "torchaudio",
# ]
# ///

"""Transcribe audio with mlx-whisper, optionally diarize with pyannote. Outputs JSON."""

import argparse
import json
import sys
from pathlib import Path

import mlx_whisper


def transcribe(audio_path: str, model: str) -> dict:
    """Run mlx-whisper transcription, returning segments with timestamps."""
    return mlx_whisper.transcribe(
        audio_path,
        path_or_hf_repo=model,
        word_timestamps=True,
        verbose=False,
    )


def diarize(audio_path: str, hf_token: str):
    """Run pyannote speaker diarization."""
    import torch
    from pyannote.audio import Pipeline

    pipeline = Pipeline.from_pretrained(
        "pyannote/speaker-diarization-3.1",
        token=hf_token,
    )
    if torch.backends.mps.is_available():
        pipeline.to(torch.device("mps"))
    elif torch.cuda.is_available():
        pipeline.to(torch.device("cuda"))
    return pipeline(audio_path)


def assign_speakers(segments: list[dict], diarization) -> list[dict]:
    """Assign a speaker label to each whisper segment based on diarization overlap."""
    labeled = []
    for seg in segments:
        seg_start = seg["start"]
        seg_end = seg["end"]
        # Find the diarization speaker with the most overlap.
        best_speaker = None
        best_overlap = 0.0
        for turn, _, speaker in diarization.itertracks(yield_label=True):
            overlap_start = max(seg_start, turn.start)
            overlap_end = min(seg_end, turn.end)
            overlap = max(0.0, overlap_end - overlap_start)
            if overlap > best_overlap:
                best_overlap = overlap
                best_speaker = speaker
        labeled.append({**seg, "speaker": best_speaker or "UNKNOWN"})
    return labeled


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("audio", help="Path to audio file")
    parser.add_argument("output", help="Path to write JSON transcript")
    parser.add_argument(
        "--model",
        default="mlx-community/whisper-large-v3-turbo",
        help="MLX whisper model (default: mlx-community/whisper-large-v3-turbo)",
    )
    parser.add_argument(
        "--diarize",
        action="store_true",
        help="Run pyannote speaker diarization (requires --hf-token)",
    )
    parser.add_argument(
        "--hf-token",
        default=None,
        help="Hugging Face token for pyannote (default: $HUGGING_FACE_TOKEN)",
    )
    args = parser.parse_args()

    import os

    audio = args.audio
    if not Path(audio).exists():
        print(f"Audio file not found: {audio}", file=sys.stderr)
        sys.exit(1)

    print(f"Transcribing {audio}...", file=sys.stderr)
    result = transcribe(audio, args.model)
    segments = result["segments"]

    if args.diarize:
        hf_token = args.hf_token or os.environ.get("HUGGING_FACE_TOKEN")
        if not hf_token:
            print("Set --hf-token or $HUGGING_FACE_TOKEN for diarization.", file=sys.stderr)
            sys.exit(1)
        print("Diarizing...", file=sys.stderr)
        diarization_result = diarize(audio, hf_token)
        segments = assign_speakers(segments, diarization_result)

    output = {
        "text": result["text"],
        "language": result.get("language"),
        "segments": segments,
    }
    Path(args.output).write_text(
        json.dumps(output, ensure_ascii=False, indent=2),
        encoding="utf-8",
    )
    print(f"Done. Wrote {len(segments)} segments to {args.output}.", file=sys.stderr)


if __name__ == "__main__":
    main()