# Copyright (c) 2024-2025, The Isaac Lab Project Developers.
# All rights reserved.
#
# SPDX-License-Identifier: Apache-2.0

"""
Script to record teleoperated demos and run mimic dataset generation in real-time.
"""

# Launching Isaac Sim Simulator first.

import argparse

from isaaclab.app import AppLauncher

# add argparse arguments
parser = argparse.ArgumentParser(
    description="Record demonstrations and run mimic dataset generation for Isaac Lab environments."
)
parser.add_argument("--task", type=str, default=None, help="Name of the task.")
parser.add_argument(
    "--num_demos", type=int, default=0, help="Number of demonstrations to record. Set to 0 for infinite."
)
parser.add_argument(
    "--num_envs",
    type=int,
    default=5,
    help=(
        "Number of environments to instantiate to test recording and generating datasets. The environment specified by"
        " `teleop_env_index` will be used for teleoperation and recording while the remaining environments will be used"
        " for real-time data generation. Default is 5."
    ),
)
parser.add_argument(
    "--teleop_env_index",
    type=int,
    default=0,
    help="Index of the environment to be used for teleoperation. Set -1 for disabling the teleop robot. Default is 0.",
)
parser.add_argument("--teleop_device", type=str, default="keyboard", help="Device for interacting with environment.")
parser.add_argument(
    "--step_hz", type=int, default=0, help="Environment stepping rate in Hz. Set to 0 for maximum speed."
)
parser.add_argument("--input_file", type=str, default=None, help="File path to the source demo dataset file.")
parser.add_argument(
    "--output_file",
    type=str,
    default="./datasets/output_dataset.hdf5",
    help="File path to export recorded episodes.",
)
parser.add_argument(
    "--generated_output_file",
    type=str,
    default=None,
    help="File path to export generated episodes by mimic.",
)
# append AppLauncher cli args
AppLauncher.add_app_launcher_args(parser)
# parse the arguments
args_cli = parser.parse_args()

# launch the simulator
app_launcher = AppLauncher(args_cli)
simulation_app = app_launcher.app

"""Rest everything follows."""

import asyncio
import contextlib
import gymnasium as gym
import numpy as np
import os
import random
import time
import torch

import isaaclab_mimic.envs  # noqa: F401
from isaaclab_mimic.datagen.data_generator import DataGenerator
from isaaclab_mimic.datagen.datagen_info_pool import DataGenInfoPool

from isaaclab.devices import Se3Keyboard, Se3SpaceMouse
from isaaclab.envs.mdp.recorders.recorders_cfg import ActionStateRecorderManagerCfg
from isaaclab.managers import DatasetExportMode, RecorderTerm, RecorderTermCfg
from isaaclab.utils import configclass
from isaaclab.utils.datasets import HDF5DatasetFileHandler

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

# global variable to keep track of the data generation statistics
num_recorded = 0
num_success = 0
num_failures = 0
num_attempts = 0


class PreStepDatagenInfoRecorder(RecorderTerm):
    """Recorder term that records the datagen info data in each step."""

    def record_pre_step(self):
        datagen_info = {
            "object_pose": self._env.scene.get_state(is_relative=True)["rigid_object"],
            "target_eef_pose": self._env.action_to_target_eef_pos(self._env.action_manager.action),
        }
        return "obs", datagen_info


@configclass
class PreStepDatagenInfoRecorderCfg(RecorderTermCfg):
    """Configuration for the datagen info recorder term."""

    class_type: type[RecorderTerm] = PreStepDatagenInfoRecorder


class PreStepSubtaskTermsObservationsRecorder(RecorderTerm):
    """Recorder term that records the subtask completion observations in each step."""

    def record_pre_step(self):
        return "obs/subtask_term_signals", self._env.obs_buf["subtask_terms"]


@configclass
class PreStepSubtaskTermsObservationsRecorderCfg(RecorderTermCfg):
    """Configuration for the step subtask terms observation recorder term."""

    class_type: type[RecorderTerm] = PreStepSubtaskTermsObservationsRecorder


@configclass
class MimicRecorderManagerCfg(ActionStateRecorderManagerCfg):
    """Mimic specific recorder terms."""

    record_pre_step_datagen_info = PreStepDatagenInfoRecorderCfg()
    record_pre_step_subtask_term_signals = PreStepSubtaskTermsObservationsRecorderCfg()


class RateLimiter:
    """Convenience class for enforcing rates in loops."""

    def __init__(self, hz):
        """
        Args:
            hz (int): frequency to enforce
        """
        self.hz = hz
        self.last_time = time.time()
        self.sleep_duration = 1.0 / hz
        self.render_period = min(0.033, self.sleep_duration)

    def sleep(self, env):
        """Attempt to sleep at the specified rate in hz."""
        next_wakeup_time = self.last_time + self.sleep_duration
        while time.time() < next_wakeup_time:
            time.sleep(self.render_period)
            env.unwrapped.sim.render()

        self.last_time = self.last_time + self.sleep_duration

        # detect time jumping forwards (e.g. loop is too slow)
        if self.last_time < time.time():
            while self.last_time < time.time():
                self.last_time += self.sleep_duration


def pre_process_actions(delta_pose: torch.Tensor, gripper_command: bool) -> torch.Tensor:
    """Pre-process actions for the environment."""
    # compute actions based on environment
    if "Reach" in args_cli.task:
        # note: reach is the only one that uses a different action space
        # compute actions
        return delta_pose
    else:
        # resolve gripper command
        gripper_vel = torch.zeros((delta_pose.shape[0], 1), dtype=torch.float, device=delta_pose.device)
        gripper_vel[:] = -1 if gripper_command else 1
        # compute actions
        return torch.concat([delta_pose, gripper_vel], dim=1)


async def run_teleop_robot(
    env, env_id, env_action_queue, shared_datagen_info_pool, exported_dataset_path, teleop_interface=None
):
    """Run teleop robot."""
    global num_recorded
    should_reset_teleop_instance = False
    # create controller if needed
    if teleop_interface is None:
        if args_cli.teleop_device.lower() == "keyboard":
            teleop_interface = Se3Keyboard(pos_sensitivity=0.2, rot_sensitivity=0.5)
        elif args_cli.teleop_device.lower() == "spacemouse":
            teleop_interface = Se3SpaceMouse(pos_sensitivity=0.2, rot_sensitivity=0.5)
        else:
            raise ValueError(
                f"Invalid device interface '{args_cli.teleop_device}'. Supported: 'keyboard', 'spacemouse'."
            )

    # add teleoperation key for reset current recording instance
    def reset_teleop_instance():
        nonlocal should_reset_teleop_instance
        should_reset_teleop_instance = True

    teleop_interface.add_callback("R", reset_teleop_instance)

    teleop_interface.reset()
    print(teleop_interface)

    recorded_episode_dataset_file_handler = HDF5DatasetFileHandler()
    recorded_episode_dataset_file_handler.create(exported_dataset_path, env_name=env.unwrapped.cfg.env_name)

    env_id_tensor = torch.tensor([env_id], dtype=torch.int64, device=env.device)
    success_delay_step_count = 10
    has_succeeded = False
    num_recorded = 0
    while True:
        if should_reset_teleop_instance:
            env.unwrapped.recorder_manager.reset(env_id_tensor)
            env.unwrapped.reset(env_ids=env_id_tensor)
            should_reset_teleop_instance = False

        # get keyboard command
        delta_pose, gripper_command = teleop_interface.advance()
        # convert to torch
        delta_pose = torch.tensor(delta_pose, dtype=torch.float, device=env.device).repeat(1, 1)
        # compute actions based on environment
        teleop_action = pre_process_actions(delta_pose, gripper_command)

        await env_action_queue.put((env_id, teleop_action))
        await env_action_queue.join()

        if has_succeeded:
            if success_delay_step_count > 0:
                success_delay_step_count -= 1
                continue

            if bool(env.is_success()[env_id]):
                env.recorder_manager.set_success_to_episodes(
                    env_id_tensor, torch.tensor([[True]], dtype=torch.bool, device=env.device)
                )
                teleop_episode = env.unwrapped.recorder_manager.get_episode(env_id)
                await shared_datagen_info_pool.add_episode(teleop_episode)

                recorded_episode_dataset_file_handler.write_episode(teleop_episode)
                recorded_episode_dataset_file_handler.flush()
                env.recorder_manager.reset(env_id_tensor)
                num_recorded += 1
                should_reset_teleop_instance = True
            else:
                has_succeeded = False
        else:
            if bool(env.is_success()[env_id]):
                has_succeeded = True
                success_delay_step_count = 10


async def run_data_generator(
    env, env_id, env_action_queue, shared_datagen_info_pool, pause_subtask=False, export_demo=True
):
    """Run data generator."""
    global num_success, num_failures, num_attempts
    data_generator = DataGenerator(env=env.unwrapped, src_demo_datagen_info_pool=shared_datagen_info_pool)
    idle_action = torch.zeros(env.unwrapped.action_space.shape)[0]
    while True:
        while data_generator.src_demo_datagen_info_pool.num_datagen_infos < 1:
            await env_action_queue.put((env_id, idle_action))
            await env_action_queue.join()

        results = await data_generator.generate(
            env_id=env_id,
            env_action_queue=env_action_queue,
            select_src_per_subtask=env.unwrapped.cfg.datagen_config.generation_select_src_per_subtask,
            transform_first_robot_pose=env.unwrapped.cfg.datagen_config.generation_transform_first_robot_pose,
            interpolate_from_last_target_pose=env.unwrapped.cfg.datagen_config.generation_interpolate_from_last_target_pose,
            pause_subtask=pause_subtask,
            export_demo=export_demo,
        )
        if bool(results["success"]):
            num_success += 1
        else:
            num_failures += 1
        num_attempts += 1


def env_loop(env, env_action_queue, shared_datagen_info_pool, asyncio_event_loop):
    """Main loop for the environment."""
    global num_recorded, num_success, num_failures, num_attempts
    prev_num_attempts = 0
    prev_num_recorded = 0

    rate_limiter = None
    if args_cli.step_hz > 0:
        rate_limiter = RateLimiter(args_cli.step_hz)

    # simulate environment -- run everything in inference mode
    is_first_print = True
    with contextlib.suppress(KeyboardInterrupt) and torch.inference_mode():
        while True:

            actions = torch.zeros(env.unwrapped.action_space.shape)

            # get actions from all the data generators
            for i in range(env.unwrapped.num_envs):
                # an async-blocking call to get an action from a data generator
                env_id, action = asyncio_event_loop.run_until_complete(env_action_queue.get())
                actions[env_id] = action

            # perform action on environment
            env.step(actions)

            # mark done so the data generators can continue with the step results
            for i in range(env.unwrapped.num_envs):
                env_action_queue.task_done()

            if prev_num_attempts != num_attempts or prev_num_recorded != num_recorded:
                prev_num_attempts = num_attempts
                prev_num_recorded = num_recorded
                generated_sucess_rate = 100 * num_success / num_attempts if num_attempts > 0 else 0.0
                if is_first_print:
                    is_first_print = False
                else:
                    print("\r", "\033[F" * 5, end="")
                print("")
                print("*" * 50, "\033[K")
                print(f"{num_recorded} teleoperated demos recorded\033[K")
                print(
                    f"{num_success}/{num_attempts} ({generated_sucess_rate:.1f}%) successful demos generated by"
                    " mimic\033[K"
                )
                print("*" * 50, "\033[K")

                if args_cli.num_demos > 0 and num_recorded >= args_cli.num_demos:
                    print(f"All {args_cli.num_demos} demonstrations recorded. Exiting the app.")
                    break

            # check that simulation is stopped or not
            if env.unwrapped.sim.is_stopped():
                break

            if rate_limiter:
                rate_limiter.sleep(env.unwrapped)
    env.close()


def main():
    num_envs = args_cli.num_envs

    # create output directory for recorded episodes if it does not exist
    recorded_output_dir = os.path.dirname(args_cli.output_file)
    if not os.path.exists(recorded_output_dir):
        os.makedirs(recorded_output_dir)

    # check if the given input dataset file exists
    if args_cli.input_file and not os.path.exists(args_cli.input_file):
        raise FileNotFoundError(f"The dataset file {args_cli.input_file} does not exist.")

    # get the environment name
    if args_cli.task is not None:
        env_name = args_cli.task
    elif args_cli.input_file:
        # if the environment name is not specified, try to get it from the dataset file
        dataset_file_handler = HDF5DatasetFileHandler()
        dataset_file_handler.open(args_cli.input_file)
        env_name = dataset_file_handler.get_env_name()
    else:
        raise ValueError("Task/env name was not specified nor found in the dataset.")

    # parse configuration
    env_cfg = parse_env_cfg(env_name, device=args_cli.device, num_envs=num_envs)
    env_cfg.env_name = env_name

    # modify configuration such that the environment runs indefinitely
    env_cfg.terminations.time_out = None
    # data generator is in charge of resetting the environment
    env_cfg.terminations.success = None

    env_cfg.observations.policy.concatenate_terms = False

    env_cfg.recorders = MimicRecorderManagerCfg()

    env_cfg.recorders.dataset_export_mode = DatasetExportMode.EXPORT_NONE
    if args_cli.generated_output_file:
        # create output directory for generated episodes if it does not exist
        generated_output_dir = os.path.dirname(args_cli.generated_output_file)
        if not os.path.exists(generated_output_dir):
            os.makedirs(generated_output_dir)
        generated_output_file_name = os.path.splitext(os.path.basename(args_cli.generated_output_file))[0]
        env_cfg.recorders.dataset_export_dir_path = generated_output_dir
        env_cfg.recorders.dataset_filename = generated_output_file_name
        env_cfg.recorders.dataset_export_mode = DatasetExportMode.EXPORT_SUCCEEDED_ONLY

    # create environment
    env = gym.make(env_name, cfg=env_cfg)

    # set seed for generation
    random.seed(env.unwrapped.cfg.datagen_config.seed)
    np.random.seed(env.unwrapped.cfg.datagen_config.seed)
    torch.manual_seed(env.unwrapped.cfg.datagen_config.seed)

    # reset before starting
    env.reset()

    # Set up asyncio stuff
    asyncio_event_loop = asyncio.get_event_loop()
    env_action_queue = asyncio.Queue()

    shared_datagen_info_pool_lock = asyncio.Lock()
    shared_datagen_info_pool = DataGenInfoPool(
        env.unwrapped, env.unwrapped.cfg, env.unwrapped.device, asyncio_lock=shared_datagen_info_pool_lock
    )
    if args_cli.input_file:
        shared_datagen_info_pool.load_from_dataset_file(args_cli.input_file)
        print(f"Loaded {shared_datagen_info_pool.num_datagen_infos} to datagen info pool")

    # make data generator object
    data_generator_asyncio_tasks = []
    for i in range(num_envs):
        if args_cli.teleop_env_index is not None and i == args_cli.teleop_env_index:
            data_generator_asyncio_tasks.append(
                asyncio_event_loop.create_task(
                    run_teleop_robot(env, i, env_action_queue, shared_datagen_info_pool, args_cli.output_file)
                )
            )
            continue
        data_generator_asyncio_tasks.append(
            asyncio_event_loop.create_task(
                run_data_generator(
                    env, i, env_action_queue, shared_datagen_info_pool, export_demo=bool(args_cli.generated_output_file)
                )
            )
        )

    try:
        asyncio.ensure_future(asyncio.gather(*data_generator_asyncio_tasks))
    except asyncio.CancelledError:
        print("Tasks were cancelled.")

    env_loop(env, env_action_queue, shared_datagen_info_pool, asyncio_event_loop)


if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        print("\nProgram interrupted by user. Exiting...")
    # close sim app
    simulation_app.close()
