"""emotion.launch.py — Launch emotion_node for facial expression recognition (Issue #161)."""

from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument
from launch.substitutions import LaunchConfiguration, PathJoinSubstitution
from launch_ros.actions import Node
from launch_ros.substitutions import FindPackageShare


def generate_launch_description() -> LaunchDescription:
    pkg = FindPackageShare("saltybot_social")
    params_file = PathJoinSubstitution([pkg, "config", "emotion_params.yaml"])

    return LaunchDescription([
        DeclareLaunchArgument(
            "params_file",
            default_value=params_file,
            description="Path to emotion_node parameter YAML",
        ),
        DeclareLaunchArgument(
            "engine_path",
            default_value="/models/emotion_fp16.trt",
            description="Path to TensorRT FP16 emotion engine (empty = landmark heuristic)",
        ),
        DeclareLaunchArgument(
            "min_confidence",
            default_value="0.40",
            description="Minimum detection confidence to publish an expression",
        ),
        DeclareLaunchArgument(
            "smoothing_alpha",
            default_value="0.30",
            description="EMA smoothing weight (0=frozen, 1=no smoothing)",
        ),
        DeclareLaunchArgument(
            "opt_out_persons",
            default_value="",
            description="Comma-separated person_ids that opted out",
        ),
        DeclareLaunchArgument(
            "landmark_fallback",
            default_value="true",
            description="Use landmark heuristic when TRT engine unavailable",
        ),
        DeclareLaunchArgument(
            "publish_context",
            default_value="true",
            description="Publish /social/emotion/context JSON for LLM context",
        ),
        Node(
            package="saltybot_social",
            executable="emotion_node",
            name="emotion_node",
            output="screen",
            parameters=[
                LaunchConfiguration("params_file"),
                {
                    "engine_path":      LaunchConfiguration("engine_path"),
                    "min_confidence":   LaunchConfiguration("min_confidence"),
                    "smoothing_alpha":  LaunchConfiguration("smoothing_alpha"),
                    "opt_out_persons":  LaunchConfiguration("opt_out_persons"),
                    "landmark_fallback": LaunchConfiguration("landmark_fallback"),
                    "publish_context":  LaunchConfiguration("publish_context"),
                },
            ],
        ),
    ])