# Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES, ETH Zurich, and University of Toronto
# All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause

"""Spacemouse controller for SE(3) control."""

from __future__ import annotations

import hid
import numpy as np
import threading
import time
from scipy.spatial.transform.rotation import Rotation
from typing import Callable

from ..device_base import DeviceBase
from .utils import convert_buffer


class Se3SpaceMouse(DeviceBase):
    """A space-mouse controller for sending SE(3) commands as delta poses.

    This class implements a space-mouse controller to provide commands to a robotic arm with a gripper.
    It uses the `HID-API`_ which interfaces with USD and Bluetooth HID-class devices across multiple platforms [1].

    The command comprises of two parts:

    * delta pose: a 6D vector of (x, y, z, roll, pitch, yaw) in meters and radians.
    * gripper: a binary command to open or close the gripper.

    Note:
        The interface finds and uses the first supported device connected to the computer.

    Currently tested for following devices:

    - SpaceMouse Compact: https://3dconnexion.com/de/product/spacemouse-compact/

    .. _HID-API: https://github.com/libusb/hidapi

    """

    def __init__(self, pos_sensitivity: float = 0.4, rot_sensitivity: float = 0.8):
        """Initialize the space-mouse layer.

        Args:
            pos_sensitivity: Magnitude of input position command scaling. Defaults to 0.4.
            rot_sensitivity: Magnitude of scale input rotation commands scaling. Defaults to 0.8.
        """
        # store inputs
        self.pos_sensitivity = pos_sensitivity
        self.rot_sensitivity = rot_sensitivity
        # acquire device interface
        self._device = hid.device()
        self._find_device()
        # read rotations
        self._read_rotation = False

        # command buffers
        self._close_gripper = False
        self._delta_pos = np.zeros(3)  # (x, y, z)
        self._delta_rot = np.zeros(3)  # (roll, pitch, yaw)
        # dictionary for additional callbacks
        self._additional_callbacks = dict()
        # run a thread for listening to device updates
        self._thread = threading.Thread(target=self._run_device)
        self._thread.daemon = True
        self._thread.start()

    def __del__(self):
        """Destructor for the class."""
        self._thread.join()

    def __str__(self) -> str:
        """Returns: A string containing the information of joystick."""
        msg = f"Spacemouse Controller for SE(3): {self.__class__.__name__}\n"
        msg += f"\tManufacturer: {self._device.get_manufacturer_string()}\n"
        msg += f"\tProduct: {self._device.get_product_string()}\n"
        msg += "\t----------------------------------------------\n"
        msg += "\tRight button: reset command\n"
        msg += "\tLeft button: toggle gripper command (open/close)\n"
        msg += "\tMove mouse laterally: move arm horizontally in x-y plane\n"
        msg += "\tMove mouse vertically: move arm vertically\n"
        msg += "\tTwist mouse about an axis: rotate arm about a corresponding axis"
        return msg

    """
    Operations
    """

    def reset(self):
        # default flags
        self._close_gripper = False
        self._delta_pos = np.zeros(3)  # (x, y, z)
        self._delta_rot = np.zeros(3)  # (roll, pitch, yaw)

    def add_callback(self, key: str, func: Callable):
        # check keys supported by callback
        if key not in ["L", "R"]:
            raise ValueError(f"Only left (L) and right (R) buttons supported. Provided: {key}.")
        # TODO: Improve this to allow multiple buttons on same key.
        self._additional_callbacks[key] = func

    def advance(self) -> tuple[np.ndarray, bool]:
        """Provides the result from spacemouse event state.

        Returns:
            A tuple containing the delta pose command and gripper commands.
        """
        rot_vec = Rotation.from_euler("XYZ", self._delta_rot).as_rotvec()
        # if new command received, reset event flag to False until keyboard updated.
        return np.concatenate([self._delta_pos, rot_vec]), self._close_gripper

    """
    Internal helpers.
    """

    def _find_device(self):
        """Find the device connected to computer."""
        found = False
        # implement a timeout for device search
        for _ in range(5):
            for device in hid.enumerate():
                if device["product_string"] == "SpaceMouse Compact":
                    # set found flag
                    found = True
                    vendor_id = device["vendor_id"]
                    product_id = device["product_id"]
                    # connect to the device
                    self._device.open(vendor_id, product_id)
            # check if device found
            if not found:
                time.sleep(1.0)
            else:
                break
        # no device found: return false
        if not found:
            raise OSError("No device found by SpaceMouse. Is the device connected?")

    def _run_device(self):
        """Listener thread that keeps pulling new messages."""
        # keep running
        while True:
            # read the device data
            data = self._device.read(7)
            if data is not None:
                # readings from 6-DoF sensor
                if data[0] == 1:
                    self._delta_pos[1] = self.pos_sensitivity * convert_buffer(data[1], data[2])
                    self._delta_pos[0] = self.pos_sensitivity * convert_buffer(data[3], data[4])
                    self._delta_pos[2] = self.pos_sensitivity * convert_buffer(data[5], data[6]) * -1.0
                elif data[0] == 2 and not self._read_rotation:
                    self._delta_rot[1] = self.rot_sensitivity * convert_buffer(data[1], data[2])
                    self._delta_rot[0] = self.rot_sensitivity * convert_buffer(data[3], data[4])
                    self._delta_rot[2] = self.rot_sensitivity * convert_buffer(data[5], data[6])
                # readings from the side buttons
                elif data[0] == 3:
                    # press left button
                    if data[1] == 1:
                        # close gripper
                        self._close_gripper = not self._close_gripper
                        # additional callbacks
                        if "L" in self._additional_callbacks:
                            self._additional_callbacks["L"]
                    # right button is for reset
                    if data[1] == 2:
                        # reset layer
                        self.reset()
                        # additional callbacks
                        if "R" in self._additional_callbacks:
                            self._additional_callbacks["R"]
                    if data[1] == 3:
                        self._read_rotation = not self._read_rotation
