main.py

import argparse
import json
import sys
from io import BytesIO
from pathlib import Path
from typing import Any, Dict, List

import numpy as np
from PIL import Image
from ultralytics import YOLO


def load_image(frame: Any, base_dir: Path) -> Image.Image:
    if isinstance(frame, (bytes, bytearray, memoryview)):
        return Image.open(BytesIO(frame)).convert("RGB")

    path = Path(str(frame))
    if not path.is_absolute():
        path = (Path.cwd() / path).resolve()
        if not path.exists():
            candidate = (base_dir / str(frame)).resolve()
            if candidate.exists():
                path = candidate
    return Image.open(path).convert("RGB")


def load_model(*_args: Any, **_kwargs: Any):
    base_dir = Path(__file__).resolve().parent
    model_path = base_dir / "weights.onnx"
    if not model_path.exists():
        return None
    return YOLO(str(model_path))


def run_model(model, frame: "np.ndarray") -> List[Dict[str, Any]]:
    image = Image.fromarray(frame)
    results = model(image)
    detections: List[Dict[str, Any]] = []
    result = results[0]
    names = result.names or model.names

    for det_idx, box in enumerate(result.boxes):
        xyxy = box.xyxy[0].tolist()
        class_id = int(box.cls[0].item())
        detections.append(
            {
                "frame_idx": 0,
                "class": names.get(class_id, str(class_id)),
                "bbox": [float(x) for x in xyxy],
                "score": float(box.conf[0].item()),
                "track_id": f"f0-d{det_idx}",
            }
        )

    return detections


def build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(description="Run logistics detection (YOLOv8 ONNX).")
    parser.add_argument(
        "--stdin-raw",
        action="store_true",
        default=True,
        help="Read raw image bytes from stdin.",
    )
    return parser


if __name__ == "__main__":
    build_parser().parse_args()

    base_dir = Path(__file__).resolve().parent
    model = load_model()
    if model is None:
        print("[]")
        sys.exit(0)

    try:
        image = load_image(sys.stdin.buffer.read(), base_dir)
    except Exception:
        print("[]")
        sys.exit(0)

    frame = np.array(image)
    output = run_model(model, frame)
    print(json.dumps(output))