"""Auto-title herdr tabs from the first user message of a Hermes session.

Separate from the herdr-agent-state plugin so that
`herdr integration install hermes` reinstalls don't clobber it.
"""

from __future__ import annotations

import json
import os
import random
import socket
import time

_SOURCE = "herdr:hermes:auto-title"
_seen_sessions: set[str] = set()


def _herdr_env() -> dict[str, str] | None:
    """Read herdr env vars if running inside a herdr pane."""
    if os.environ.get("HERDR_ENV") != "1":
        return None
    tab_id = os.environ.get("HERDR_TAB_ID", "").strip()
    socket_path = os.environ.get("HERDR_SOCKET_PATH", "").strip()
    if not tab_id or not socket_path:
        return None
    return {"tab_id": tab_id, "socket_path": socket_path}


def _send(method: str, params: dict) -> None:
    env = _herdr_env()
    if env is None:
        return
    request = {
        "id": f"{_SOURCE}:{int(time.time() * 1000)}:{random.randrange(1_000_000):06d}",
        "method": method,
        "params": {**params, "tab_id": env["tab_id"]},
    }
    try:
        client = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
        client.settimeout(0.5)
        client.connect(env["socket_path"])
        client.sendall((json.dumps(request) + "\n").encode("utf-8"))
        try:
            client.recv(4096)
        except Exception:
            pass
        client.close()
    except Exception:
        pass


def _session_id(kwargs: dict) -> str | None:
    value = kwargs.get("session_id")
    if isinstance(value, str) and value:
        return value
    return None


def _post_llm_call_title(**kwargs) -> None:
    """Set the herdr tab title from the first user message of a session."""
    session_id = _session_id(kwargs) or ""
    if not session_id or session_id in _seen_sessions:
        return
    user_msg = kwargs.get("user_message", "")
    if not user_msg or not isinstance(user_msg, str):
        return
    title = user_msg.split("\n")[0].strip()[:40]
    if not title:
        return
    _send("tab.rename", {"label": title})
    _seen_sessions.add(session_id)


def _on_session_start_reset(**kwargs) -> None:
    """Allow re-titling when a new session starts."""
    session_id = _session_id(kwargs)
    if session_id:
        _seen_sessions.discard(session_id)


def register(ctx):
    ctx.register_hook("on_session_start", _on_session_start_reset)
    ctx.register_hook("post_llm_call", _post_llm_call_title)