import uuid

from sqlalchemy.ext.asyncio import AsyncSession

from app.models.game import Game

TOOL_SCHEMA = {
    "name": "update_monster_hp",
    "description": (
        "Track an NPC's/monster's hit points during a fight — call this whenever one is introduced "
        "or takes damage, so the server can detect when it's defeated. This is DM-only bookkeeping, "
        "never shown to players; keep narrating combat and secrecy (e.g. AC) exactly as before."
    ),
    "parameters": {
        "type": "object",
        "properties": {
            "name": {
                "type": "string",
                "description": "The monster's/NPC's name, used consistently across calls to identify it.",
            },
            "current_hp": {"type": "integer"},
            "max_hp": {"type": "integer"},
        },
        "required": ["name", "current_hp", "max_hp"],
    },
}


async def update(session: AsyncSession, game_id: uuid.UUID, tool_input: dict) -> dict:
    game = await session.get(Game, game_id)
    if game is None:
        raise ValueError(f"Game {game_id} not found")

    name = tool_input["name"]
    current_hp = tool_input["current_hp"]
    max_hp = tool_input["max_hp"]

    # Build an entirely new list of new dicts rather than mutating existing ones in place:
    # SQLAlchemy compares the old and new JSONB value by content to decide whether a flush is
    # needed, and an in-place mutation makes the "old" value (still referenced by the attribute)
    # look identical to the "new" one by the time of that comparison, so the UPDATE silently
    # gets skipped.
    updated_entry = {"name": name, "current_hp": current_hp, "max_hp": max_hp}
    monsters = [dict(m) for m in (game.monsters or []) if m.get("name") != name]
    monsters.append(updated_entry)

    game.monsters = monsters
    await session.commit()

    return {"name": name, "current_hp": current_hp, "max_hp": max_hp, "defeated": current_hp <= 0}