import logging
import sys

import torch

from mmdet.core import (bbox2roi, bbox_mapping, merge_aug_bboxes,
                        merge_aug_masks, multiclass_nms)

logger = logging.getLogger(__name__)
if sys.version_info >= (3, 7):
    from mmdet.utils.contextmanagers import completed


class BBoxTestMixin:

    if sys.version_info >= (3, 7):

        async def async_test_bboxes(self,
                                    x,
                                    img_metas,
                                    proposals,
                                    rcnn_test_cfg,
                                    rescale=False,
                                    **kwargs):
            """Asynchronized test for box head without augmentation."""
            rois = bbox2roi(proposals)
            roi_feats = self.bbox_roi_extractor(
                x[:len(self.bbox_roi_extractor.featmap_strides)], rois)
            if self.with_shared_head:
                roi_feats = self.shared_head(roi_feats)
            sleep_interval = rcnn_test_cfg.get('async_sleep_interval', 0.017)

            async with completed(
                    __name__, 'bbox_head_forward',
                    sleep_interval=sleep_interval):
                cls_score, bbox_pred = self.bbox_head(roi_feats)

            img_shape = img_metas[0]['img_shape']
            scale_factor = img_metas[0]['scale_factor']
            det_bboxes, det_labels = self.bbox_head.get_bboxes(
                rois,
                cls_score,
                bbox_pred,
                img_shape,
                scale_factor,
                rescale=rescale,
                cfg=rcnn_test_cfg)
            return det_bboxes, det_labels

    def simple_test_bboxes(self,
                           x,
                           img_metas,
                           proposals,
                           rcnn_test_cfg,
                           rescale=False):
        """Test only det bboxes without augmentation.

        Args:
            x (tuple[Tensor]): Feature maps of all scale level.
            img_metas (list[dict]): Image meta info.
            proposals (List[Tensor]): Region proposals.
            rcnn_test_cfg (obj:`ConfigDict`): `test_cfg` of R-CNN.
            rescale (bool): If True, return boxes in original image space.
                Default: False.

        Returns:
            tuple[list[Tensor], list[Tensor]]: The first list contains
                the boxes of the corresponding image in a batch, each
                tensor has the shape (num_boxes, 5) and last dimension
                5 represent (tl_x, tl_y, br_x, br_y, score). Each Tensor
                in the second list is the labels with shape (num_boxes, ).
                The length of both lists should be equal to batch_size.
        """
        # get origin input shape to support onnx dynamic input shape

        img_shapes = tuple(meta['img_shape'] for meta in img_metas)
        scale_factors = tuple(meta['scale_factor'] for meta in img_metas)

        # The length of proposals of different batches may be different.
        # In order to form a batch, a padding operation is required.
        max_size = max([proposal.size(0) for proposal in proposals])
        # padding to form a batch
        for i, proposal in enumerate(proposals):
            supplement = proposal.new_full(
                (max_size - proposal.size(0), proposal.size(1)), 0)
            proposals[i] = torch.cat((supplement, proposal), dim=0)
        rois = torch.stack(proposals, dim=0)

        batch_index = torch.arange(
            rois.size(0), device=rois.device).float().view(-1, 1, 1).expand(
                rois.size(0), rois.size(1), 1)
        rois = torch.cat([batch_index, rois[..., :4]], dim=-1)
        batch_size = rois.shape[0]
        num_proposals_per_img = rois.shape[1]

        # Eliminate the batch dimension
        rois = rois.view(-1, 5)
        bbox_results = self._bbox_forward(x, rois)
        cls_score = bbox_results['cls_score']
        bbox_pred = bbox_results['bbox_pred']

        # Recover the batch dimension
        rois = rois.reshape(batch_size, num_proposals_per_img, rois.size(-1))
        cls_score = cls_score.reshape(batch_size, num_proposals_per_img,
                                      cls_score.size(-1))

        # remove padding, ignore batch_index when calculating mask
        supplement_mask = rois.abs()[..., 1:].sum(dim=-1) == 0
        cls_score[supplement_mask, :] = 0

        # bbox_pred would be None in some detector when with_reg is False,
        # e.g. Grid R-CNN.
        if bbox_pred is not None:
            # the bbox prediction of some detectors like SABL is not Tensor
            if isinstance(bbox_pred, torch.Tensor):
                bbox_pred = bbox_pred.reshape(batch_size,
                                              num_proposals_per_img,
                                              bbox_pred.size(-1))
                bbox_pred[supplement_mask, :] = 0
            else:
                # TODO: Looking forward to a better way
                # TODO move these special process to a corresponding head
                # For SABL
                bbox_preds = self.bbox_head.bbox_pred_split(
                    bbox_pred, num_proposals_per_img)
                # apply bbox post-processing to each image individually
                det_bboxes = []
                det_labels = []
                for i in range(len(proposals)):
                    # remove padding
                    supplement_mask = proposals[i].abs().sum(dim=-1) == 0
                    for bbox in bbox_preds[i]:
                        bbox[supplement_mask] = 0
                    det_bbox, det_label = self.bbox_head.get_bboxes(
                        rois[i],
                        cls_score[i],
                        bbox_preds[i],
                        img_shapes[i],
                        scale_factors[i],
                        rescale=rescale,
                        cfg=rcnn_test_cfg)
                    det_bboxes.append(det_bbox)
                    det_labels.append(det_label)
                return det_bboxes, det_labels
        else:
            bbox_pred = None

        return self.bbox_head.get_bboxes(
            rois,
            cls_score,
            bbox_pred,
            img_shapes,
            scale_factors,
            rescale=rescale,
            cfg=rcnn_test_cfg)

    def aug_test_bboxes(self, feats, img_metas, proposal_list, rcnn_test_cfg):
        """Test det bboxes with test time augmentation."""
        aug_bboxes = []
        aug_scores = []
        for x, img_meta in zip(feats, img_metas):
            # only one image in the batch
            img_shape = img_meta[0]['img_shape']
            scale_factor = img_meta[0]['scale_factor']
            flip = img_meta[0]['flip']
            flip_direction = img_meta[0]['flip_direction']
            # TODO more flexible
            proposals = bbox_mapping(proposal_list[0][:, :4], img_shape,
                                     scale_factor, flip, flip_direction)
            rois = bbox2roi([proposals])
            bbox_results = self._bbox_forward(x, rois)
            bboxes, scores = self.bbox_head.get_bboxes(
                rois,
                bbox_results['cls_score'],
                bbox_results['bbox_pred'],
                img_shape,
                scale_factor,
                rescale=False,
                cfg=None)
            aug_bboxes.append(bboxes)
            aug_scores.append(scores)
        # after merging, bboxes will be rescaled to the original image size
        merged_bboxes, merged_scores = merge_aug_bboxes(
            aug_bboxes, aug_scores, img_metas, rcnn_test_cfg)
        det_bboxes, det_labels = multiclass_nms(merged_bboxes, merged_scores,
                                                rcnn_test_cfg.score_thr,
                                                rcnn_test_cfg.nms,
                                                rcnn_test_cfg.max_per_img)
        return det_bboxes, det_labels


class MaskTestMixin:

    if sys.version_info >= (3, 7):

        async def async_test_mask(self,
                                  x,
                                  img_metas,
                                  det_bboxes,
                                  det_labels,
                                  rescale=False,
                                  mask_test_cfg=None):
            """Asynchronized test for mask head without augmentation."""
            # image shape of the first image in the batch (only one)
            ori_shape = img_metas[0]['ori_shape']
            scale_factor = img_metas[0]['scale_factor']
            if det_bboxes.shape[0] == 0:
                segm_result = [[] for _ in range(self.mask_head.num_classes)]
            else:
                if rescale:
                    scale_factor = det_bboxes.new_tensor(scale_factor)
                _bboxes = (
                    det_bboxes[:, :4] *
                    scale_factor if rescale else det_bboxes)
                mask_rois = bbox2roi([_bboxes])
                mask_feats = self.mask_roi_extractor(
                    x[:len(self.mask_roi_extractor.featmap_strides)],
                    mask_rois)

                if self.with_shared_head:
                    mask_feats = self.shared_head(mask_feats)
                if mask_test_cfg and mask_test_cfg.get('async_sleep_interval'):
                    sleep_interval = mask_test_cfg['async_sleep_interval']
                else:
                    sleep_interval = 0.035
                async with completed(
                        __name__,
                        'mask_head_forward',
                        sleep_interval=sleep_interval):
                    mask_pred = self.mask_head(mask_feats)
                segm_result = self.mask_head.get_seg_masks(
                    mask_pred, _bboxes, det_labels, self.test_cfg, ori_shape,
                    scale_factor, rescale)
            return segm_result

    def simple_test_mask(self,
                         x,
                         img_metas,
                         det_bboxes,
                         det_labels,
                         rescale=False):
        """Simple test for mask head without augmentation."""
        # image shapes of images in the batch
        ori_shapes = tuple(meta['ori_shape'] for meta in img_metas)
        scale_factors = tuple(meta['scale_factor'] for meta in img_metas)

        if all(det_bbox.shape[0] == 0 for det_bbox in det_bboxes):
            segm_results = [[[] for _ in range(self.mask_head.num_classes)]
                            for _ in range(len(det_bboxes))]
            return segm_results

        # The length of proposals of different batches may be different.
        # In order to form a batch, a padding operation is required.

        # padding to form a batch
        max_size = max([bboxes.size(0) for bboxes in det_bboxes])
        for i, (bbox, label) in enumerate(zip(det_bboxes, det_labels)):
            supplement_bbox = bbox.new_full(
                (max_size - bbox.size(0), bbox.size(1)), 0)
            supplement_label = label.new_full((max_size - label.size(0), ), 0)
            det_bboxes[i] = torch.cat((supplement_bbox, bbox), dim=0)
            det_labels[i] = torch.cat((supplement_label, label), dim=0)
        det_bboxes = torch.stack(det_bboxes, dim=0)
        det_labels = torch.stack(det_labels, dim=0)

        batch_size = det_bboxes.size(0)
        num_proposals_per_img = det_bboxes.shape[1]

        # if det_bboxes is rescaled to the original image size, we need to
        # rescale it back to the testing scale to obtain RoIs.
        det_bboxes = det_bboxes[..., :4]
        if rescale:
            scale_factors = det_bboxes.new_tensor(scale_factors)
            det_bboxes = det_bboxes * scale_factors.unsqueeze(1)

        batch_index = torch.arange(
            det_bboxes.size(0), device=det_bboxes.device).float().view(
                -1, 1, 1).expand(det_bboxes.size(0), det_bboxes.size(1), 1)
        mask_rois = torch.cat([batch_index, det_bboxes], dim=-1)
        mask_rois = mask_rois.view(-1, 5)
        mask_results = self._mask_forward(x, mask_rois)
        mask_pred = mask_results['mask_pred']

        # Recover the batch dimension
        mask_preds = mask_pred.reshape(batch_size, num_proposals_per_img,
                                       *mask_pred.shape[1:])

        # apply mask post-processing to each image individually
        segm_results = []
        for i in range(batch_size):
            mask_pred = mask_preds[i]
            det_bbox = det_bboxes[i]
            det_label = det_labels[i]

            # remove padding
            supplement_mask = det_bbox.abs().sum(dim=-1) != 0
            mask_pred = mask_pred[supplement_mask]
            det_bbox = det_bbox[supplement_mask]
            det_label = det_label[supplement_mask]

            if det_label.shape[0] == 0:
                segm_results.append([[]
                                     for _ in range(self.mask_head.num_classes)
                                     ])
            else:
                segm_result = self.mask_head.get_seg_masks(
                    mask_pred, det_bbox, det_label, self.test_cfg,
                    ori_shapes[i], scale_factors[i], rescale)
                segm_results.append(segm_result)
        return segm_results

    def aug_test_mask(self, feats, img_metas, det_bboxes, det_labels):
        """Test for mask head with test time augmentation."""
        if det_bboxes.shape[0] == 0:
            segm_result = [[] for _ in range(self.mask_head.num_classes)]
        else:
            aug_masks = []
            for x, img_meta in zip(feats, img_metas):
                img_shape = img_meta[0]['img_shape']
                scale_factor = img_meta[0]['scale_factor']
                flip = img_meta[0]['flip']
                flip_direction = img_meta[0]['flip_direction']
                _bboxes = bbox_mapping(det_bboxes[:, :4], img_shape,
                                       scale_factor, flip, flip_direction)
                mask_rois = bbox2roi([_bboxes])
                mask_results = self._mask_forward(x, mask_rois)
                # convert to numpy array to save memory
                aug_masks.append(
                    mask_results['mask_pred'].sigmoid().cpu().numpy())
            merged_masks = merge_aug_masks(aug_masks, img_metas, self.test_cfg)

            ori_shape = img_metas[0][0]['ori_shape']
            scale_factor = det_bboxes.new_ones(4)
            segm_result = self.mask_head.get_seg_masks(
                merged_masks,
                det_bboxes,
                det_labels,
                self.test_cfg,
                ori_shape,
                scale_factor=scale_factor,
                rescale=False)
        return segm_result
