# Copyright (C) 2024-present Naver Corporation. All rights reserved.
# Licensed under CC BY-NC-SA 4.0 (non-commercial use only).
#
# --------------------------------------------------------
# Dataloader for preprocessed scannet++
# dataset at https://github.com/scannetpp/scannetpp - non-commercial research and educational purposes
# https://kaldir.vc.in.tum.de/scannetpp/static/scannetpp-terms-of-use.pdf
# See datasets_preprocess/preprocess_scannetpp.py
# --------------------------------------------------------
import os.path as osp
import cv2
import numpy as np

from dust3r.datasets.base.base_stereo_view_dataset import BaseStereoViewDataset
from dust3r.utils.image import imread_cv2


class ScanNetpp(BaseStereoViewDataset):
    def __init__(self, *args, ROOT, **kwargs):
        self.ROOT = ROOT
        super().__init__(*args, **kwargs)
        assert self.split == 'train'
        self.loaded_data = self._load_data()

    def _load_data(self):
        with np.load(osp.join(self.ROOT, 'all_metadata.npz')) as data:
            self.scenes = data['scenes']
            self.sceneids = data['sceneids']
            self.images = data['images']
            self.intrinsics = data['intrinsics'].astype(np.float32)
            self.trajectories = data['trajectories'].astype(np.float32)
            self.pairs = data['pairs'][:, :2].astype(int)

    def __len__(self):
        return len(self.pairs)

    def _get_views(self, idx, resolution, rng):

        image_idx1, image_idx2 = self.pairs[idx]

        views = []
        for view_idx in [image_idx1, image_idx2]:
            scene_id = self.sceneids[view_idx]
            scene_dir = osp.join(self.ROOT, self.scenes[scene_id])

            intrinsics = self.intrinsics[view_idx]
            camera_pose = self.trajectories[view_idx]
            basename = self.images[view_idx]

            # Load RGB image
            rgb_image = imread_cv2(osp.join(scene_dir, 'images', basename + '.jpg'))
            # Load depthmap
            depthmap = imread_cv2(osp.join(scene_dir, 'depth', basename + '.png'), cv2.IMREAD_UNCHANGED)
            depthmap = depthmap.astype(np.float32) / 1000
            depthmap[~np.isfinite(depthmap)] = 0  # invalid

            rgb_image, depthmap, intrinsics = self._crop_resize_if_necessary(
                rgb_image, depthmap, intrinsics, resolution, rng=rng, info=view_idx)

            views.append(dict(
                img=rgb_image,
                depthmap=depthmap.astype(np.float32),
                camera_pose=camera_pose.astype(np.float32),
                camera_intrinsics=intrinsics.astype(np.float32),
                dataset='ScanNet++',
                label=self.scenes[scene_id] + '_' + basename,
                instance=f'{str(idx)}_{str(view_idx)}',
            ))
        return views


if __name__ == "__main__":
    from dust3r.datasets.base.base_stereo_view_dataset import view_name
    from dust3r.viz import SceneViz, auto_cam_size
    from dust3r.utils.image import rgb

    dataset = ScanNetpp(split='train', ROOT="data/scannetpp_processed", resolution=224, aug_crop=16)

    for idx in np.random.permutation(len(dataset)):
        views = dataset[idx]
        assert len(views) == 2
        print(view_name(views[0]), view_name(views[1]))
        viz = SceneViz()
        poses = [views[view_idx]['camera_pose'] for view_idx in [0, 1]]
        cam_size = max(auto_cam_size(poses), 0.001)
        for view_idx in [0, 1]:
            pts3d = views[view_idx]['pts3d']
            valid_mask = views[view_idx]['valid_mask']
            colors = rgb(views[view_idx]['img'])
            viz.add_pointcloud(pts3d, colors, valid_mask)
            viz.add_camera(pose_c2w=views[view_idx]['camera_pose'],
                           focal=views[view_idx]['camera_intrinsics'][0, 0],
                           color=(idx*255, (1 - idx)*255, 0),
                           image=colors,
                           cam_size=cam_size)
        viz.show()