"""Bring up the robot: camera, face, face detection, audio levels, the MCP bridge and the thermal guard.

  ros2 launch hermes_bringup robot.launch.py [camera:=false] [face:=false] [vision:=false] [audio:=false] [mcp:=false] [thermal:=false]
                                              [start_delay:=6.0]

Every node is its own process and is respawned if it exits, so one crash cannot take the others
down: the face keeps running when the camera does not. Parameters are in config/robot.yaml.

The face starts at once; the camera, vision, audio and MCP nodes wait start_delay seconds, so the four
Python processes do not fight over the CPU while the face imports and draws its first frame.
"""
import os

from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument, TimerAction
from launch.conditions import IfCondition
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import Node

# (launch argument, package, executable, node name in robot.yaml)
NODES = [
    ('camera', 'camera_ros', 'camera_node', 'camera'),
    ('face', 'hermes_face', 'face_node', 'hermes_face'),
    ('vision', 'hermes_vision', 'face_detector', 'hermes_face_detector'),
    ('audio', 'hermes_audio', 'audio_state', 'hermes_audio_state'),
    ('mcp', 'hermes_mcp', 'mcp_server', 'hermes_mcp'),
    ('thermal', 'hermes_thermal', 'thermal_guard', 'hermes_thermal'),
]


DELAYED = {'camera', 'vision', 'audio', 'mcp', 'thermal'}


def generate_launch_description():
    params = os.path.join(get_package_share_directory('hermes_bringup'), 'config', 'robot.yaml')
    actions = [DeclareLaunchArgument(arg, default_value='true', description=f'run the {name} node')
               for arg, _, _, name in NODES]
    actions.append(DeclareLaunchArgument('start_delay', default_value='6.0',
                                         description='seconds the other nodes wait for the face'))
    for arg, package, executable, name in NODES:
        node = Node(package=package, executable=executable, name=name, output='screen',
                    parameters=[params], respawn=True, respawn_delay=2.0,
                    condition=IfCondition(LaunchConfiguration(arg)))
        actions.append(TimerAction(period=LaunchConfiguration('start_delay'), actions=[node])
                       if arg in DELAYED else node)
    return LaunchDescription(actions)