"""Cheap sentiment classifier for the message board's UI tint.

One LLM call (default model) every time the board changes — classifies the
recent posts as positive | neutral | negative. The board's background colour
maps to that label client-side. Characters do not see this signal — it's a
user-facing affordance only.
"""

from __future__ import annotations

from backend.factory import get_llm
from game.models import DEFAULT_MODEL_ID

from .world import WorldState

LABELS = ("positive", "neutral", "negative")


def classify_board(world: WorldState) -> str:
    if not world.board:
        return "neutral"
    tail = "\n".join(f"{p.author}: {p.text}" for p in world.board[-10:])
    backend = get_llm(DEFAULT_MODEL_ID)
    raw = backend.generate(
        system_prompt=(
            "Classify the overall mood of the following message-board posts. "
            "Reply with exactly one word: positive, neutral, or negative."
        ),
        user_prompt=tail,
    )
    word = (raw or "").strip().lower().split()[0:1]
    if word and word[0] in LABELS:
        return word[0]
    return "neutral"