#!/usr/bin/env python3
"""Publish one flight_intent JSON to a ROS1 std_msgs/String topic (for flight bridge).

Run after sourcing ROS, e.g.:
  source /opt/ros/noetic/setup.bash && python3 -m voice_drone.tools.publish_flight_intent_ros_once /tmp/intent.json

Or from repo root（须在已 source ROS 的 shell 中，且勿覆盖 ROS 的 PYTHONPATH；应 prepend）:
  export PYTHONPATH="$PWD:$PYTHONPATH" && python3 -m voice_drone.tools.publish_flight_intent_ros_once ...
"""
from __future__ import annotations

import argparse
import json
import sys
from pathlib import Path
from typing import Any

import rospy
from std_msgs.msg import String


def _load_payload(path: str | None) -> dict[str, Any]:
    if path and path != "-":
        raw = Path(path).read_text(encoding="utf-8")
    else:
        raw = sys.stdin.read()
    data = json.loads(raw)
    if not isinstance(data, dict):
        raise ValueError("root must be a JSON object")
    return data


def main() -> None:
    ap = argparse.ArgumentParser(description="Publish flight_intent JSON once to ROS String topic")
    ap.add_argument(
        "json_file",
        nargs="?",
        default="-",
        help="Path to JSON file, or - for stdin (default: stdin)",
    )
    ap.add_argument("--topic", default="/input", help="ROS topic (default: /input)")
    ap.add_argument(
        "--wait-subscribers",
        type=float,
        default=0.0,
        help="Seconds to wait for at least one subscriber (default: 0)",
    )
    args = ap.parse_args()

    payload = _load_payload(args.json_file if args.json_file != "-" else None)
    json_str = json.dumps(payload, ensure_ascii=False, separators=(",", ":"))

    rospy.init_node("flight_intent_ros_publisher_once", anonymous=True)
    pub = rospy.Publisher(args.topic, String, queue_size=1, latch=False)
    deadline = rospy.Time.now() + rospy.Duration(args.wait_subscribers)
    while args.wait_subscribers > 0 and pub.get_num_connections() < 1 and not rospy.is_shutdown():
        if rospy.Time.now() > deadline:
            break
        rospy.sleep(0.05)
    rospy.sleep(0.15)
    pub.publish(String(data=json_str))
    rospy.sleep(0.25)


if __name__ == "__main__":
    main()