# YOLOv5 🚀 by Ultralytics, GPL-3.0 license
"""
PyTorch Hub models https://pytorch.org/hub/ultralytics_yolov5/

Usage:
    import torch
    model = torch.hub.load('ultralytics/yolov5', 'yolov5s')
    model = torch.hub.load('ultralytics/yolov5:master', 'custom', 'path/to/yolov5s.onnx')  # file from branch
"""

import torch


def _create(
    name, pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None
):
    """Creates a specified YOLOv5 model

    Arguments:
        name (str): name of model, i.e. 'yolov5s'
        pretrained (bool): load pretrained weights into the model
        channels (int): number of input channels
        classes (int): number of model classes
        autoshape (bool): apply YOLOv5 .autoshape() wrapper to model
        verbose (bool): print all information to screen
        device (str, torch.device, None): device to use for model parameters

    Returns:
        YOLOv5 pytorch model
    """
    from pathlib import Path

    from models.common import AutoShape, DetectMultiBackend
    from models.yolo import Model
    from utils.downloads import attempt_download
    from utils.general import check_requirements, intersect_dicts, set_logging
    from utils.torch_utils import select_device

    check_requirements(exclude=("tensorboard", "thop", "opencv-python"))
    set_logging(verbose=verbose)

    name = Path(name)
    path = name.with_suffix(".pt") if name.suffix == "" else name  # checkpoint path
    try:
        device = select_device(
            ("0" if torch.cuda.is_available() else "cpu") if device is None else device
        )

        if pretrained and channels == 3 and classes == 80:
            model = DetectMultiBackend(path, device=device)  # download/load FP32 model
            # model = models.experimental.attempt_load(path, map_location=device)  # download/load FP32 model
        else:
            cfg = list((Path(__file__).parent / "models").rglob(f"{path.stem}.yaml"))[
                0
            ]  # model.yaml path
            model = Model(cfg, channels, classes)  # create model
            if pretrained:
                ckpt = torch.load(attempt_download(path), map_location=device)  # load
                csd = ckpt["model"].float().state_dict()  # checkpoint state_dict as FP32
                csd = intersect_dicts(csd, model.state_dict(), exclude=["anchors"])  # intersect
                model.load_state_dict(csd, strict=False)  # load
                if len(ckpt["model"].names) == classes:
                    model.names = ckpt["model"].names  # set class names attribute
        if autoshape:
            model = AutoShape(model)  # for file/URI/PIL/cv2/np inputs and NMS
        return model.to(device)

    except Exception as e:
        help_url = "https://github.com/ultralytics/yolov5/issues/36"
        s = f"{e}. Cache may be out of date, try `force_reload=True` or see {help_url} for help."
        raise Exception(s) from e


def custom(path="path/to/model.pt", autoshape=True, verbose=True, device=None):
    # YOLOv5 custom or local model
    return _create(path, autoshape=autoshape, verbose=verbose, device=device)


def yolov5n(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-nano model https://github.com/ultralytics/yolov5
    return _create("yolov5n", pretrained, channels, classes, autoshape, verbose, device)


def yolov5s(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-small model https://github.com/ultralytics/yolov5
    return _create("yolov5s", pretrained, channels, classes, autoshape, verbose, device)


def yolov5m(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-medium model https://github.com/ultralytics/yolov5
    return _create("yolov5m", pretrained, channels, classes, autoshape, verbose, device)


def yolov5l(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-large model https://github.com/ultralytics/yolov5
    return _create("yolov5l", pretrained, channels, classes, autoshape, verbose, device)


def yolov5x(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-xlarge model https://github.com/ultralytics/yolov5
    return _create("yolov5x", pretrained, channels, classes, autoshape, verbose, device)


def yolov5n6(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-nano-P6 model https://github.com/ultralytics/yolov5
    return _create("yolov5n6", pretrained, channels, classes, autoshape, verbose, device)


def yolov5s6(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-small-P6 model https://github.com/ultralytics/yolov5
    return _create("yolov5s6", pretrained, channels, classes, autoshape, verbose, device)


def yolov5m6(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-medium-P6 model https://github.com/ultralytics/yolov5
    return _create("yolov5m6", pretrained, channels, classes, autoshape, verbose, device)


def yolov5l6(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-large-P6 model https://github.com/ultralytics/yolov5
    return _create("yolov5l6", pretrained, channels, classes, autoshape, verbose, device)


def yolov5x6(pretrained=True, channels=3, classes=80, autoshape=True, verbose=True, device=None):
    # YOLOv5-xlarge-P6 model https://github.com/ultralytics/yolov5
    return _create("yolov5x6", pretrained, channels, classes, autoshape, verbose, device)


if __name__ == "__main__":
    model = _create(
        name="yolov5s", pretrained=True, channels=3, classes=80, autoshape=True, verbose=True
    )  # pretrained
    # model = custom(path='path/to/model.pt')  # custom

    # Verify inference
    from pathlib import Path

    import cv2
    import numpy as np
    from PIL import Image

    imgs = [
        "data/images/zidane.jpg",  # filename
        Path("data/images/zidane.jpg"),  # Path
        "https://ultralytics.com/images/zidane.jpg",  # URI
        cv2.imread("data/images/bus.jpg")[:, :, ::-1],  # OpenCV
        Image.open("data/images/bus.jpg"),  # PIL
        np.zeros((320, 640, 3)),
    ]  # numpy

    results = model(imgs, size=320)  # batched inference
    results.print()
    results.save()