#!/usr/bin/env python3
"""
Game LLM behavior configuration loader.

Loads YAML configuration that defines:
- system_prompt: Injected as the first "system" message for chat completions
- scenario, rules: Arbitrary metadata available to the app if needed
- start_message: Initial assistant message shown to the user
"""

from __future__ import annotations

from dataclasses import dataclass, field
from pathlib import Path
from typing import Any, Dict, Optional, Union

import yaml


@dataclass
class GameConfig:
    system_prompt: str = ""
    scenario: Dict[str, Any] = field(default_factory=dict)
    rules: list[str] = field(default_factory=list)
    start_message: str = ""

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> "GameConfig":
        return cls(
            system_prompt=str(data.get("system_prompt", "") or ""),
            scenario=dict(data.get("scenario", {}) or {}),
            rules=list(data.get("rules", []) or []),
            start_message=str(data.get("start_message", "") or ""),
        )


def load_game_config(path: Union[str, Path] = "config/game_config.yaml") -> GameConfig:
    """
    Load the game configuration from YAML. Returns defaults if the file is missing or invalid.

    Args:
        path: Path to the YAML config file.

    Returns:
        GameConfig: Parsed configuration or defaults.
    """
    p = Path(path)
    if not p.exists():
        # Return defaults if config is missing
        return GameConfig()

    try:
        with p.open("r", encoding="utf-8") as f:
            raw = yaml.safe_load(f) or {}
        if not isinstance(raw, dict):
            return GameConfig()
        return GameConfig.from_dict(raw)
    except Exception:
        # Fail-closed to defaults to keep the app usable
        return GameConfig()