# Copyright 2024 DeepMind Technologies Limited
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
import argparse
from pathlib import Path
from tqdm import tqdm

import mujoco
from mujoco.usd import exporter

def generate_usd_trajectory(args):
  """Generates a USD file from a mujoco trajectory."""
  # load a model to mujoco
  model_path = args.model_path
  m = mujoco.MjModel.from_xml_path(model_path)
  d = mujoco.MjData(m)

  # create an instance of the USDExporter
  exp = exporter.USDExporter(model=m,
                             output_directory_name=Path(args.model_path).stem,
                             output_directory_root=args.output_directory_root,
                             camera_names=args.camera_names)

  # step through the model for length steps
  for _ in tqdm(range(args.length)):
    for _ in range(args.steps_per_frame):
      mujoco.mj_step(m, d)
    exp.update_scene(d)

  exp.save_scene(filetype=args.export_extension)

if __name__ == "__main__":

  parser = argparse.ArgumentParser()

  parser.add_argument('--model_path',
                      type=str,
                      required=True,
                      help='path to mjcf xml model')

  parser.add_argument('--length',
                      type=int,
                      default=100,
                      help='length of trajectory to render')

  parser.add_argument('--output_directory_root',
                      type=str,
                      default="../usd_trajectories/",
                      help='location where to create usd files')

  parser.add_argument('--camera_names',
                      type=str,
                      nargs='+',
                      help='cameras to include in usd')

  parser.add_argument('--export_extension',
                      type=str,
                      default="usd",
                      help='extension of exported file (usd, usda, or usdc)')

  parser.add_argument('--steps_per_frame',
                      type=int,
                      default=1,
                      help='number of frames to skip for each rendering step')

  args = parser.parse_args()
  generate_usd_trajectory(args)