"""配置加载：backend/config.json（可从 config.example.json 复制修改）。

未配置 api_key 时，AI 玩家自动回退为内置启发式 AI，游戏依然完整可玩。
支持环境变量覆盖：WEREWOLF_LLM_BASE_URL / WEREWOLF_LLM_API_KEY / WEREWOLF_LLM_MODEL。
"""
from __future__ import annotations

import json
import os
from dataclasses import dataclass, field
from pathlib import Path

BACKEND_DIR = Path(__file__).resolve().parent.parent
CONFIG_PATH = BACKEND_DIR / "config.json"
EXAMPLE_PATH = BACKEND_DIR / "config.example.json"


@dataclass
class LLMConfig:
    base_url: str = ""
    api_key: str = ""
    model: str = ""
    temperature: float = 0.8

    @property
    def configured(self) -> bool:
        return bool(self.base_url and self.api_key and self.model)


@dataclass
class ServerConfig:
    host: str = "0.0.0.0"
    port: int = 8000


@dataclass
class AppConfig:
    llm: LLMConfig = field(default_factory=LLMConfig)
    server: ServerConfig = field(default_factory=ServerConfig)


def load_config() -> AppConfig:
    cfg = AppConfig()
    source = CONFIG_PATH
    if not source.exists() and EXAMPLE_PATH.exists():
        source = EXAMPLE_PATH
    if source.exists():
        try:
            raw = json.loads(source.read_text(encoding="utf-8"))
        except (json.JSONDecodeError, OSError):
            raw = {}
        llm = raw.get("llm", {})
        cfg.llm.base_url = llm.get("base_url", cfg.llm.base_url)
        cfg.llm.api_key = llm.get("api_key", cfg.llm.api_key)
        cfg.llm.model = llm.get("model", cfg.llm.model)
        cfg.llm.temperature = float(llm.get("temperature", cfg.llm.temperature))
        srv = raw.get("server", {})
        cfg.server.host = srv.get("host", cfg.server.host)
        cfg.server.port = int(srv.get("port", cfg.server.port))

    cfg.llm.base_url = os.environ.get("WEREWOLF_LLM_BASE_URL", cfg.llm.base_url).strip()
    cfg.llm.api_key = os.environ.get("WEREWOLF_LLM_API_KEY", cfg.llm.api_key).strip()
    cfg.llm.model = os.environ.get("WEREWOLF_LLM_MODEL", cfg.llm.model).strip()
    return cfg


CONFIG = load_config()