# Copyright (c) OpenMMLab. All rights reserved.
# Copyright (c) 2019 Western Digital Corporation or its affiliates.
import torch

from ..builder import DETECTORS
from .single_stage import SingleStageDetector


@DETECTORS.register_module()
class YOLOV3(SingleStageDetector):

    def __init__(self,
                 backbone,
                 neck,
                 bbox_head,
                 train_cfg=None,
                 test_cfg=None,
                 pretrained=None,
                 init_cfg=None):
        super(YOLOV3, self).__init__(backbone, neck, bbox_head, train_cfg,
                                     test_cfg, pretrained, init_cfg)

    def onnx_export(self, img, img_metas):
        """Test function for exporting to ONNX, without test time augmentation.

        Args:
            img (torch.Tensor): input images.
            img_metas (list[dict]): List of image information.

        Returns:
            tuple[Tensor, Tensor]: dets of shape [N, num_det, 5]
                and class labels of shape [N, num_det].
        """
        x = self.extract_feat(img)
        outs = self.bbox_head.forward(x)
        # get shape as tensor
        img_shape = torch._shape_as_tensor(img)[2:]
        img_metas[0]['img_shape_for_onnx'] = img_shape

        det_bboxes, det_labels = self.bbox_head.onnx_export(*outs, img_metas)

        return det_bboxes, det_labels