# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
# All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause

"""Deploy a LEAPP-exported policy in an Isaac Lab simulation."""

"""Launch Isaac Sim Simulator first."""

import argparse
import sys

from isaaclab.app import AppLauncher

parser = argparse.ArgumentParser(description="Deploy a LEAPP-exported policy in simulation.")
parser.add_argument("--task", type=str, default=None, help="Name of the registered Isaac Lab task.")
parser.add_argument("--leapp_model", type=str, default=None, help="Path to the LEAPP .yaml pipeline description.")
parser.add_argument("--seed", type=int, default=None, help="Seed for the environment.")
AppLauncher.add_app_launcher_args(parser)
args_cli, hydra_args = parser.parse_known_args()

if args_cli.task is None or args_cli.leapp_model is None:
    missing_args = []
    if args_cli.task is None:
        missing_args.append("--task")
    if args_cli.leapp_model is None:
        missing_args.append("--leapp_model")
    parser.error(f"the following arguments are required: {', '.join(missing_args)}")

sys.argv = [sys.argv[0]] + hydra_args

app_launcher = AppLauncher(args_cli)
simulation_app = app_launcher.app

"""Rest everything follows."""

import torch

from isaaclab.envs.leapp_deployment_env import LeappDeploymentEnv

import isaaclab_tasks  # noqa: F401
from isaaclab_tasks.utils.parse_cfg import load_cfg_from_registry


def main():
    # ── Load env config from gym registry ─────────────────────────
    task_name = args_cli.task.split(":")[-1]
    env_cfg = load_cfg_from_registry(task_name, "env_cfg_entry_point")

    if args_cli.seed is not None:
        env_cfg.seed = args_cli.seed
    if args_cli.device is not None:
        env_cfg.sim.device = args_cli.device

    # ── Create deploy env ─────────────────────────────────────────
    env = LeappDeploymentEnv(env_cfg, args_cli.leapp_model)

    if getattr(args_cli, "headless", False):
        print(
            "[WARN]: Running deploy without a viewport. This happens when headless mode is active, "
            "including the default case where no visualizer was selected. The policy may be "
            "stepping normally, but no viewport will appear unless you specify the "
            "`--visualizer` field."
        )

    print(f"[INFO]: Deploying task '{task_name}' with LEAPP model: {args_cli.leapp_model}")
    print(f"[INFO]: Num envs: {env.num_envs}, decimation: {env.cfg.decimation}, step_dt: {env.step_dt:.4f}s")

    # ── Run loop ──────────────────────────────────────────────────
    env.reset()
    try:
        with torch.inference_mode():
            while simulation_app.is_running():
                env.step()
        env.close()
    except KeyboardInterrupt:
        pass


if __name__ == "__main__":
    main()
    simulation_app.close()