# Copyright (c) OpenMMLab. All rights reserved.
import copy
import mmcv
import numpy as np
import pyquaternion
import tempfile
import torch
import warnings
from nuscenes.utils.data_classes import Box as NuScenesBox
from os import path as osp

from mmdet3d.core import bbox3d2result, box3d_multiclass_nms, xywhr2xyxyr
from mmdet.datasets import DATASETS, CocoDataset
from mmdet3d.core import show_multi_modality_result
from mmdet3d.core.bbox import CameraInstance3DBoxes, get_box_type
from mmdet3d.datasets.pipelines import Compose
from mmdet3d.datasets.utils import extract_result_dict, get_loading_pipeline


@DATASETS.register_module()
class CustomNuScenesMonoDataset(CocoDataset):
    r"""Monocular 3D detection on NuScenes Dataset.
    This class serves as the API for experiments on the NuScenes Dataset.
    Please refer to `NuScenes Dataset <https://www.nuscenes.org/download>`_
    for data downloading.
    Args:
        ann_file (str): Path of annotation file.
        data_root (str): Path of dataset root.
        load_interval (int, optional): Interval of loading the dataset. It is
            used to uniformly sample the dataset. Defaults to 1.
        with_velocity (bool, optional): Whether include velocity prediction
            into the experiments. Defaults to True.
        modality (dict, optional): Modality to specify the sensor data used
            as input. Defaults to None.
        box_type_3d (str, optional): Type of 3D box of this dataset.
            Based on the `box_type_3d`, the dataset will encapsulate the box
            to its original format then converted them to `box_type_3d`.
            Defaults to 'Camera' in this class. Available options includes.
            - 'LiDAR': Box in LiDAR coordinates.
            - 'Depth': Box in depth coordinates, usually for indoor dataset.
            - 'Camera': Box in camera coordinates.
        eval_version (str, optional): Configuration version of evaluation.
            Defaults to  'detection_cvpr_2019'.
        use_valid_flag (bool): Whether to use `use_valid_flag` key in the info
            file as mask to filter gt_boxes and gt_names. Defaults to False.
        version (str, optional): Dataset version. Defaults to 'v1.0-trainval'.
    """
    CLASSES = ('car', 'truck', 'trailer', 'bus', 'construction_vehicle',
               'bicycle', 'motorcycle', 'pedestrian', 'traffic_cone',
               'barrier')
    DefaultAttribute = {
        'car': 'vehicle.parked',
        'pedestrian': 'pedestrian.moving',
        'trailer': 'vehicle.parked',
        'truck': 'vehicle.parked',
        'bus': 'vehicle.moving',
        'motorcycle': 'cycle.without_rider',
        'construction_vehicle': 'vehicle.parked',
        'bicycle': 'cycle.without_rider',
        'barrier': '',
        'traffic_cone': '',
    }
    # https://github.com/nutonomy/nuscenes-devkit/blob/57889ff20678577025326cfc24e57424a829be0a/python-sdk/nuscenes/eval/detection/evaluate.py#L222 # noqa
    ErrNameMapping = {
        'trans_err': 'mATE',
        'scale_err': 'mASE',
        'orient_err': 'mAOE',
        'vel_err': 'mAVE',
        'attr_err': 'mAAE'
    }

    def __init__(self,
                 data_root,
                 load_interval=1,
                 with_velocity=True,
                 modality=None,
                 box_type_3d='Camera',
                 eval_version='detection_cvpr_2019',
                 use_valid_flag=False,
                 overlap_test=False,
                 version='v1.0-trainval',
                 **kwargs):
        super().__init__(**kwargs)
        # overlap_test = True
        self.data_root = data_root
        self.overlap_test = overlap_test
        self.load_interval = load_interval
        self.with_velocity = with_velocity
        self.modality = modality
        self.box_type_3d, self.box_mode_3d = get_box_type(box_type_3d)
        self.eval_version = eval_version
        self.use_valid_flag = use_valid_flag
        self.bbox_code_size = 9
        self.version = version
        if self.eval_version is not None:
            from nuscenes.eval.detection.config import config_factory
            self.eval_detection_configs = config_factory(self.eval_version)
        if self.modality is None:
            self.modality = dict(
                use_camera=True,
                use_lidar=False,
                use_radar=False,
                use_map=False,
                use_external=False)

    def pre_pipeline(self, results):
        """Initialization before data preparation.
        Args:
            results (dict): Dict before data preprocessing.
                - img_fields (list): Image fields.
                - bbox3d_fields (list): 3D bounding boxes fields.
                - pts_mask_fields (list): Mask fields of points.
                - pts_seg_fields (list): Mask fields of point segments.
                - bbox_fields (list): Fields of bounding boxes.
                - mask_fields (list): Fields of masks.
                - seg_fields (list): Segment fields.
                - box_type_3d (str): 3D box type.
                - box_mode_3d (str): 3D box mode.
        """
        results['img_prefix'] = ''  # self.img_prefix
        # print('img_prefix', self.img_prefix)
        results['seg_prefix'] = self.seg_prefix
        results['proposal_file'] = self.proposal_file
        results['img_fields'] = []
        results['bbox3d_fields'] = []
        results['pts_mask_fields'] = []
        results['pts_seg_fields'] = []
        results['bbox_fields'] = []
        results['mask_fields'] = []
        results['seg_fields'] = []
        results['box_type_3d'] = self.box_type_3d
        results['box_mode_3d'] = self.box_mode_3d

    def _parse_ann_info(self, img_info, ann_info):
        """Parse bbox annotation.
        Args:
            img_info (list[dict]): Image info.
            ann_info (list[dict]): Annotation info of an image.
        Returns:
            dict: A dict containing the following keys: bboxes, labels, \
                gt_bboxes_3d, gt_labels_3d, attr_labels, centers2d, \
                depths, bboxes_ignore, masks, seg_map
        """
        gt_bboxes = []
        gt_labels = []
        attr_labels = []
        gt_bboxes_ignore = []
        gt_masks_ann = []
        gt_bboxes_cam3d = []
        centers2d = []
        depths = []
        for i, ann in enumerate(ann_info):
            if ann.get('ignore', False):
                continue
            x1, y1, w, h = ann['bbox']
            inter_w = max(0, min(x1 + w, img_info['width']) - max(x1, 0))
            inter_h = max(0, min(y1 + h, img_info['height']) - max(y1, 0))
            if inter_w * inter_h == 0:
                continue
            if ann['area'] <= 0 or w < 1 or h < 1:
                continue
            if ann['category_id'] not in self.cat_ids:
                continue
            bbox = [x1, y1, x1 + w, y1 + h]
            if ann.get('iscrowd', False):
                gt_bboxes_ignore.append(bbox)
            else:
                gt_bboxes.append(bbox)
                gt_labels.append(self.cat2label[ann['category_id']])
                attr_labels.append(ann['attribute_id'])
                gt_masks_ann.append(ann.get('segmentation', None))
                # 3D annotations in camera coordinates
                bbox_cam3d = np.array(ann['bbox_cam3d']).reshape(1, -1)
                velo_cam3d = np.array(ann['velo_cam3d']).reshape(1, 2)
                nan_mask = np.isnan(velo_cam3d[:, 0])
                velo_cam3d[nan_mask] = [0.0, 0.0]
                bbox_cam3d = np.concatenate([bbox_cam3d, velo_cam3d], axis=-1)
                gt_bboxes_cam3d.append(bbox_cam3d.squeeze())
                # 2.5D annotations in camera coordinates
                center2d = ann['center2d'][:2]
                depth = ann['center2d'][2]
                centers2d.append(center2d)
                depths.append(depth)

        if gt_bboxes:
            gt_bboxes = np.array(gt_bboxes, dtype=np.float32)
            gt_labels = np.array(gt_labels, dtype=np.int64)
            attr_labels = np.array(attr_labels, dtype=np.int64)
        else:
            gt_bboxes = np.zeros((0, 4), dtype=np.float32)
            gt_labels = np.array([], dtype=np.int64)
            attr_labels = np.array([], dtype=np.int64)

        if gt_bboxes_cam3d:
            gt_bboxes_cam3d = np.array(gt_bboxes_cam3d, dtype=np.float32)
            centers2d = np.array(centers2d, dtype=np.float32)
            depths = np.array(depths, dtype=np.float32)
        else:
            gt_bboxes_cam3d = np.zeros((0, self.bbox_code_size),
                                       dtype=np.float32)
            centers2d = np.zeros((0, 2), dtype=np.float32)
            depths = np.zeros((0), dtype=np.float32)

        gt_bboxes_cam3d = CameraInstance3DBoxes(
            gt_bboxes_cam3d,
            box_dim=gt_bboxes_cam3d.shape[-1],
            origin=(0.5, 0.5, 0.5))
        gt_labels_3d = copy.deepcopy(gt_labels)

        if gt_bboxes_ignore:
            gt_bboxes_ignore = np.array(gt_bboxes_ignore, dtype=np.float32)
        else:
            gt_bboxes_ignore = np.zeros((0, 4), dtype=np.float32)

        seg_map = img_info['filename'].replace('jpg', 'png')

        ann = dict(
            bboxes=gt_bboxes,
            labels=gt_labels,
            gt_bboxes_3d=gt_bboxes_cam3d,
            gt_labels_3d=gt_labels_3d,
            attr_labels=attr_labels,
            centers2d=centers2d,
            depths=depths,
            bboxes_ignore=gt_bboxes_ignore,
            masks=gt_masks_ann,
            seg_map=seg_map)

        return ann

    def get_attr_name(self, attr_idx, label_name):
        """Get attribute from predicted index.
        This is a workaround to predict attribute when the predicted velocity
        is not reliable. We map the predicted attribute index to the one
        in the attribute set. If it is consistent with the category, we will
        keep it. Otherwise, we will use the default attribute.
        Args:
            attr_idx (int): Attribute index.
            label_name (str): Predicted category name.
        Returns:
            str: Predicted attribute name.
        """
        # TODO: Simplify the variable name
        AttrMapping_rev2 = [
            'cycle.with_rider', 'cycle.without_rider', 'pedestrian.moving',
            'pedestrian.standing', 'pedestrian.sitting_lying_down',
            'vehicle.moving', 'vehicle.parked', 'vehicle.stopped', 'None'
        ]
        if label_name == 'car' or label_name == 'bus' \
            or label_name == 'truck' or label_name == 'trailer' \
                or label_name == 'construction_vehicle':
            if AttrMapping_rev2[attr_idx] == 'vehicle.moving' or \
                AttrMapping_rev2[attr_idx] == 'vehicle.parked' or \
                    AttrMapping_rev2[attr_idx] == 'vehicle.stopped':
                return AttrMapping_rev2[attr_idx]
            else:
                return CustomNuScenesMonoDataset.DefaultAttribute[label_name]
        elif label_name == 'pedestrian':
            if AttrMapping_rev2[attr_idx] == 'pedestrian.moving' or \
                AttrMapping_rev2[attr_idx] == 'pedestrian.standing' or \
                    AttrMapping_rev2[attr_idx] == \
                    'pedestrian.sitting_lying_down':
                return AttrMapping_rev2[attr_idx]
            else:
                return CustomNuScenesMonoDataset.DefaultAttribute[label_name]
        elif label_name == 'bicycle' or label_name == 'motorcycle':
            if AttrMapping_rev2[attr_idx] == 'cycle.with_rider' or \
                    AttrMapping_rev2[attr_idx] == 'cycle.without_rider':
                return AttrMapping_rev2[attr_idx]
            else:
                return CustomNuScenesMonoDataset.DefaultAttribute[label_name]
        else:
            return CustomNuScenesMonoDataset.DefaultAttribute[label_name]

    def _format_bbox(self, results, jsonfile_prefix=None):
        """Convert the results to the standard format.
        Args:
            results (list[dict]): Testing results of the dataset.
            jsonfile_prefix (str): The prefix of the output jsonfile.
                You can specify the output directory/filename by
                modifying the jsonfile_prefix. Default: None.
        Returns:
            str: Path of the output json file.
        """
        nusc_annos = {}
        mapped_class_names = self.CLASSES

        print('Start to convert detection format...')

        CAM_NUM = 6

        for sample_id, det in enumerate(mmcv.track_iter_progress(results)):

            if sample_id % CAM_NUM == 0:
                boxes_per_frame = []
                attrs_per_frame = []

            # need to merge results from images of the same sample
            annos = []
            boxes, attrs = output_to_nusc_box(det)
            sample_token = self.data_infos[sample_id]['token']
            boxes, attrs = cam_nusc_box_to_global(self.data_infos[sample_id],
                                                  boxes, attrs,
                                                  mapped_class_names,
                                                  self.eval_detection_configs,
                                                  self.eval_version)

            boxes_per_frame.extend(boxes)
            attrs_per_frame.extend(attrs)
            # Remove redundant predictions caused by overlap of images
            if (sample_id + 1) % CAM_NUM != 0:
                continue
            boxes = global_nusc_box_to_cam(
                self.data_infos[sample_id + 1 - CAM_NUM], boxes_per_frame,
                mapped_class_names, self.eval_detection_configs,
                self.eval_version)
            cam_boxes3d, scores, labels = nusc_box_to_cam_box3d(boxes)
            # box nms 3d over 6 images in a frame
            # TODO: move this global setting into config
            nms_cfg = dict(
                use_rotate_nms=True,
                nms_across_levels=False,
                nms_pre=4096,
                nms_thr=0.05,
                score_thr=0.01,
                min_bbox_size=0,
                max_per_frame=500)
            from mmcv import Config
            nms_cfg = Config(nms_cfg)
            cam_boxes3d_for_nms = xywhr2xyxyr(cam_boxes3d.bev)
            boxes3d = cam_boxes3d.tensor
            # generate attr scores from attr labels
            attrs = labels.new_tensor([attr for attr in attrs_per_frame])
            boxes3d, scores, labels, attrs = box3d_multiclass_nms(
                boxes3d,
                cam_boxes3d_for_nms,
                scores,
                nms_cfg.score_thr,
                nms_cfg.max_per_frame,
                nms_cfg,
                mlvl_attr_scores=attrs)
            cam_boxes3d = CameraInstance3DBoxes(boxes3d, box_dim=9)
            det = bbox3d2result(cam_boxes3d, scores, labels, attrs)
            boxes, attrs = output_to_nusc_box(det)
            boxes, attrs = cam_nusc_box_to_global(
                self.data_infos[sample_id + 1 - CAM_NUM], boxes, attrs,
                mapped_class_names, self.eval_detection_configs,
                self.eval_version)

            for i, box in enumerate(boxes):
                name = mapped_class_names[box.label]
                attr = self.get_attr_name(attrs[i], name)
                nusc_anno = dict(
                    sample_token=sample_token,
                    translation=box.center.tolist(),
                    size=box.wlh.tolist(),
                    rotation=box.orientation.elements.tolist(),
                    velocity=box.velocity[:2].tolist(),
                    detection_name=name,
                    detection_score=box.score,
                    attribute_name=attr)
                annos.append(nusc_anno)
            # other views results of the same frame should be concatenated
            if sample_token in nusc_annos:
                nusc_annos[sample_token].extend(annos)
            else:
                nusc_annos[sample_token] = annos

        nusc_submissions = {
            'meta': self.modality,
            'results': nusc_annos,
        }

        mmcv.mkdir_or_exist(jsonfile_prefix)
        res_path = osp.join(jsonfile_prefix, 'results_nusc.json')
        print('Results writes to', res_path)
        mmcv.dump(nusc_submissions, res_path)
        return res_path

    def _evaluate_single(self,
                         result_path,
                         logger=None,
                         metric='bbox',
                         result_name='img_bbox'):
        """Evaluation for a single model in nuScenes protocol.
        Args:
            result_path (str): Path of the result file.
            logger (logging.Logger | str | None): Logger used for printing
                related information during evaluation. Default: None.
            metric (str): Metric name used for evaluation. Default: 'bbox'.
            result_name (str): Result name in the metric prefix.
                Default: 'img_bbox'.
        Returns:
            dict: Dictionary of evaluation details.
        """
        from nuscenes import NuScenes
        #from nuscenes.eval.detection.evaluate import NuScenesEval
        from .nuscnes_eval import NuScenesEval_custom
        output_dir = osp.join(*osp.split(result_path)[:-1])
        self.nusc = NuScenes(
            version=self.version, dataroot=self.data_root, verbose=False)
        eval_set_map = {
            'v1.0-mini': 'mini_val',
            'v1.0-trainval': 'val',
        }
        # nusc_eval = NuScenesEval(
        #     nusc,
        #     config=self.eval_detection_configs,
        #     result_path=result_path,
        #     eval_set=eval_set_map[self.version],
        #     output_dir=output_dir,
        #     verbose=False)
        self.nusc_eval = NuScenesEval_custom(
            self.nusc,
            config=self.eval_detection_configs,
            result_path=result_path,
            eval_set=eval_set_map[self.version],
            output_dir=output_dir,
            verbose=True,
            overlap_test=self.overlap_test,
            data_infos=self.data_infos
            )

        self.nusc_eval.main(render_curves=True)

        # record metrics
        metrics = mmcv.load(osp.join(output_dir, 'metrics_summary.json'))
        detail = dict()
        metric_prefix = f'{result_name}_NuScenes'
        for name in self.CLASSES:
            for k, v in metrics['label_aps'][name].items():
                val = float('{:.4f}'.format(v))
                detail['{}/{}_AP_dist_{}'.format(metric_prefix, name, k)] = val
            for k, v in metrics['label_tp_errors'][name].items():
                val = float('{:.4f}'.format(v))
                detail['{}/{}_{}'.format(metric_prefix, name, k)] = val
            for k, v in metrics['tp_errors'].items():
                val = float('{:.4f}'.format(v))
                detail['{}/{}'.format(metric_prefix,
                                      self.ErrNameMapping[k])] = val

        detail['{}/NDS'.format(metric_prefix)] = metrics['nd_score']
        detail['{}/mAP'.format(metric_prefix)] = metrics['mean_ap']
        return detail

    def format_results(self, results, jsonfile_prefix=None, **kwargs):
        """Format the results to json (standard format for COCO evaluation).
        Args:
            results (list[tuple | numpy.ndarray]): Testing results of the
                dataset.
            jsonfile_prefix (str | None): The prefix of json files. It includes
                the file path and the prefix of filename, e.g., "a/b/prefix".
                If not specified, a temp file will be created. Default: None.
        Returns:
            tuple: (result_files, tmp_dir), result_files is a dict containing \
                the json filepaths, tmp_dir is the temporal directory created \
                for saving json files when jsonfile_prefix is not specified.
        """
        assert isinstance(results, list), 'results must be a list'
        assert len(results) == len(self), (
            'The length of results is not equal to the dataset len: {} != {}'.
            format(len(results), len(self)))

        if jsonfile_prefix is None:
            tmp_dir = tempfile.TemporaryDirectory()
            jsonfile_prefix = osp.join(tmp_dir.name, 'results')
        else:
            tmp_dir = None

        # currently the output prediction results could be in two formats
        # 1. list of dict('boxes_3d': ..., 'scores_3d': ..., 'labels_3d': ...)
        # 2. list of dict('pts_bbox' or 'img_bbox':
        #     dict('boxes_3d': ..., 'scores_3d': ..., 'labels_3d': ...))
        # this is a workaround to enable evaluation of both formats on nuScenes
        # refer to https://github.com/open-mmlab/mmdetection3d/issues/449
        if not ('pts_bbox' in results[0] or 'img_bbox' in results[0]):
            result_files = self._format_bbox(results, jsonfile_prefix)
        else:
            # should take the inner dict out of 'pts_bbox' or 'img_bbox' dict
            result_files = dict()
            for name in results[0]:
                # not evaluate 2D predictions on nuScenes
                if '2d' in name:
                    continue
                print(f'\nFormating bboxes of {name}')
                results_ = [out[name] for out in results]
                tmp_file_ = osp.join(jsonfile_prefix, name)
                result_files.update(
                    {name: self._format_bbox(results_, tmp_file_)})

        return result_files, tmp_dir

    def evaluate(self,
                 results,
                 metric='bbox',
                 logger=None,
                 jsonfile_prefix=None,
                 result_names=['img_bbox'],
                 show=False,
                 out_dir=None,
                 pipeline=None):
        """Evaluation in nuScenes protocol.
        Args:
            results (list[dict]): Testing results of the dataset.
            metric (str | list[str]): Metrics to be evaluated.
            logger (logging.Logger | str | None): Logger used for printing
                related information during evaluation. Default: None.
            jsonfile_prefix (str | None): The prefix of json files. It includes
                the file path and the prefix of filename, e.g., "a/b/prefix".
                If not specified, a temp file will be created. Default: None.
            show (bool): Whether to visualize.
                Default: False.
            out_dir (str): Path to save the visualization results.
                Default: None.
            pipeline (list[dict], optional): raw data loading for showing.
                Default: None.
        Returns:
            dict[str, float]: Results of each evaluation metric.
        """

        result_files, tmp_dir = self.format_results(results, jsonfile_prefix)

        if isinstance(result_files, dict):
            results_dict = dict()
            for name in result_names:
                print('Evaluating bboxes of {}'.format(name))
                ret_dict = self._evaluate_single(result_files[name])
            results_dict.update(ret_dict)
        elif isinstance(result_files, str):
            results_dict = self._evaluate_single(result_files)

        if tmp_dir is not None:
            tmp_dir.cleanup()

        if show:
            self.show(results, out_dir, pipeline=pipeline)
        return results_dict

    def _extract_data(self, index, pipeline, key, load_annos=False):
        """Load data using input pipeline and extract data according to key.
        Args:
            index (int): Index for accessing the target data.
            pipeline (:obj:`Compose`): Composed data loading pipeline.
            key (str | list[str]): One single or a list of data key.
            load_annos (bool): Whether to load data annotations.
                If True, need to set self.test_mode as False before loading.
        Returns:
            np.ndarray | torch.Tensor | list[np.ndarray | torch.Tensor]:
                A single or a list of loaded data.
        """
        assert pipeline is not None, 'data loading pipeline is not provided'
        img_info = self.data_infos[index]
        input_dict = dict(img_info=img_info)

        if load_annos:
            ann_info = self.get_ann_info(index)
            input_dict.update(dict(ann_info=ann_info))

        self.pre_pipeline(input_dict)
        example = pipeline(input_dict)

        # extract data items according to keys
        if isinstance(key, str):
            data = extract_result_dict(example, key)
        else:
            data = [extract_result_dict(example, k) for k in key]

        return data

    def _get_pipeline(self, pipeline):
        """Get data loading pipeline in self.show/evaluate function.
        Args:
            pipeline (list[dict] | None): Input pipeline. If None is given, \
                get from self.pipeline.
        """
        if pipeline is None:
            if not hasattr(self, 'pipeline') or self.pipeline is None:
                warnings.warn(
                    'Use default pipeline for data loading, this may cause '
                    'errors when data is on ceph')
                return self._build_default_pipeline()
            loading_pipeline = get_loading_pipeline(self.pipeline.transforms)
            return Compose(loading_pipeline)
        return Compose(pipeline)

    def _build_default_pipeline(self):
        """Build the default pipeline for this dataset."""
        pipeline = [
            dict(type='LoadImageFromFileMono3D'),
            dict(
                type='DefaultFormatBundle3D',
                class_names=self.CLASSES,
                with_label=False),
            dict(type='Collect3D', keys=['img'])
        ]
        return Compose(pipeline)

    def show(self, results, out_dir, show=True, pipeline=None):
        """Results visualization.
        Args:
            results (list[dict]): List of bounding boxes results.
            out_dir (str): Output directory of visualization result.
            show (bool): Visualize the results online.
            pipeline (list[dict], optional): raw data loading for showing.
                Default: None.
        """
        assert out_dir is not None, 'Expect out_dir, got none.'
        pipeline = self._get_pipeline(pipeline)
        for i, result in enumerate(results):
            if 'img_bbox' in result.keys():
                result = result['img_bbox']
            data_info = self.data_infos[i]
            img_path = data_info['file_name']
            file_name = osp.split(img_path)[-1].split('.')[0]
            img, img_metas = self._extract_data(i, pipeline,
                                                ['img', 'img_metas'])
            # need to transpose channel to first dim
            img = img.numpy().transpose(1, 2, 0)
            gt_bboxes = self.get_ann_info(i)['gt_bboxes_3d']
            pred_bboxes = result['boxes_3d']
            show_multi_modality_result(
                img,
                gt_bboxes,
                pred_bboxes,
                img_metas['cam2img'],
                out_dir,
                file_name,
                box_mode='camera',
                show=show)


def output_to_nusc_box(detection):
    """Convert the output to the box class in the nuScenes.
    Args:
        detection (dict): Detection results.
            - boxes_3d (:obj:`BaseInstance3DBoxes`): Detection bbox.
            - scores_3d (torch.Tensor): Detection scores.
            - labels_3d (torch.Tensor): Predicted box labels.
            - attrs_3d (torch.Tensor, optional): Predicted attributes.
    Returns:
        list[:obj:`NuScenesBox`]: List of standard NuScenesBoxes.
    """
    box3d = detection['boxes_3d']
    scores = detection['scores_3d'].numpy()
    labels = detection['labels_3d'].numpy()
    attrs = None
    if 'attrs_3d' in detection:
        attrs = detection['attrs_3d'].numpy()

    box_gravity_center = box3d.gravity_center.numpy()
    box_dims = box3d.dims.numpy()
    box_yaw = box3d.yaw.numpy()

    # convert the dim/rot to nuscbox convention
    box_dims[:, [0, 1, 2]] = box_dims[:, [2, 0, 1]]
    box_yaw = -box_yaw

    box_list = []
    for i in range(len(box3d)):
        q1 = pyquaternion.Quaternion(axis=[0, 0, 1], radians=box_yaw[i])
        q2 = pyquaternion.Quaternion(axis=[1, 0, 0], radians=np.pi / 2)
        quat = q2 * q1
        velocity = (box3d.tensor[i, 7], 0.0, box3d.tensor[i, 8])
        box = NuScenesBox(
            box_gravity_center[i],
            box_dims[i],
            quat,
            label=labels[i],
            score=scores[i],
            velocity=velocity)
        box_list.append(box)
    return box_list, attrs


def cam_nusc_box_to_global(info,
                           boxes,
                           attrs,
                           classes,
                           eval_configs,
                           eval_version='detection_cvpr_2019'):
    """Convert the box from camera to global coordinate.
    Args:
        info (dict): Info for a specific sample data, including the
            calibration information.
        boxes (list[:obj:`NuScenesBox`]): List of predicted NuScenesBoxes.
        classes (list[str]): Mapped classes in the evaluation.
        eval_configs (object): Evaluation configuration object.
        eval_version (str): Evaluation version.
            Default: 'detection_cvpr_2019'
    Returns:
        list: List of standard NuScenesBoxes in the global
            coordinate.
    """
    box_list = []
    attr_list = []
    for (box, attr) in zip(boxes, attrs):
        # Move box to ego vehicle coord system
        box.rotate(pyquaternion.Quaternion(info['cam2ego_rotation']))
        box.translate(np.array(info['cam2ego_translation']))
        # filter det in ego.
        cls_range_map = eval_configs.class_range
        radius = np.linalg.norm(box.center[:2], 2)
        det_range = cls_range_map[classes[box.label]]
        if radius > det_range:
            continue
        # Move box to global coord system
        box.rotate(pyquaternion.Quaternion(info['ego2global_rotation']))
        box.translate(np.array(info['ego2global_translation']))
        box_list.append(box)
        attr_list.append(attr)
    return box_list, attr_list


def global_nusc_box_to_cam(info,
                           boxes,
                           classes,
                           eval_configs,
                           eval_version='detection_cvpr_2019'):
    """Convert the box from global to camera coordinate.
    Args:
        info (dict): Info for a specific sample data, including the
            calibration information.
        boxes (list[:obj:`NuScenesBox`]): List of predicted NuScenesBoxes.
        classes (list[str]): Mapped classes in the evaluation.
        eval_configs (object): Evaluation configuration object.
        eval_version (str): Evaluation version.
            Default: 'detection_cvpr_2019'
    Returns:
        list: List of standard NuScenesBoxes in the global
            coordinate.
    """
    box_list = []
    for box in boxes:
        # Move box to ego vehicle coord system
        box.translate(-np.array(info['ego2global_translation']))
        box.rotate(
            pyquaternion.Quaternion(info['ego2global_rotation']).inverse)
        # filter det in ego.
        cls_range_map = eval_configs.class_range
        radius = np.linalg.norm(box.center[:2], 2)
        det_range = cls_range_map[classes[box.label]]
        if radius > det_range:
            continue
        # Move box to camera coord system
        box.translate(-np.array(info['cam2ego_translation']))
        box.rotate(pyquaternion.Quaternion(info['cam2ego_rotation']).inverse)
        box_list.append(box)
    return box_list


def nusc_box_to_cam_box3d(boxes):
    """Convert boxes from :obj:`NuScenesBox` to :obj:`CameraInstance3DBoxes`.
    Args:
        boxes (list[:obj:`NuScenesBox`]): List of predicted NuScenesBoxes.
    Returns:
        tuple (:obj:`CameraInstance3DBoxes` | torch.Tensor | torch.Tensor): \
            Converted 3D bounding boxes, scores and labels.
    """
    locs = torch.Tensor([b.center for b in boxes]).view(-1, 3)
    dims = torch.Tensor([b.wlh for b in boxes]).view(-1, 3)
    rots = torch.Tensor([b.orientation.yaw_pitch_roll[0]
                         for b in boxes]).view(-1, 1)
    velocity = torch.Tensor([b.velocity[:2] for b in boxes]).view(-1, 2)

    # convert nusbox to cambox convention
    dims[:, [0, 1, 2]] = dims[:, [1, 2, 0]]
    rots = -rots

    boxes_3d = torch.cat([locs, dims, rots, velocity], dim=1).cuda()
    cam_boxes3d = CameraInstance3DBoxes(
        boxes_3d, box_dim=9, origin=(0.5, 0.5, 0.5))
    scores = torch.Tensor([b.score for b in boxes]).cuda()
    labels = torch.LongTensor([b.label for b in boxes]).cuda()
    nms_scores = scores.new_zeros(scores.shape[0], 10 + 1)
    indices = labels.new_tensor(list(range(scores.shape[0])))
    nms_scores[indices, labels] = scores
    return cam_boxes3d, nms_scores, labels
