import threading
from typing import Any
import insightface

import roop.globals
from roop.typing import Frame

FACE_ANALYSER = None
THREAD_LOCK = threading.Lock()


def get_face_analyser() -> Any:
    global FACE_ANALYSER

    with THREAD_LOCK:
        if FACE_ANALYSER is None:
            FACE_ANALYSER = insightface.app.FaceAnalysis(name='buffalo_l', providers=roop.globals.execution_providers)
            FACE_ANALYSER.prepare(ctx_id=0, det_size=(640, 640))
    return FACE_ANALYSER


def get_one_face(frame: Frame) -> Any:
    face = get_face_analyser().get(frame)
    try:
        return min(face, key=lambda x: x.bbox[0])
    except ValueError:
        return None


def get_many_faces(frame: Frame) -> Any:
    try:
        return get_face_analyser().get(frame)
    except IndexError:
        return None