"""全局配置。

数据库默认使用 SQLite，迁移 MySQL 只需修改 DATABASE_URL：
    mysql+pymysql://user:pwd@host:3306/unis_board?charset=utf8mb4
其余代码无需改动（SQLAlchemy 负责方言差异）。
"""
from __future__ import annotations

import os
from pathlib import Path

BASE_DIR = Path(__file__).resolve().parent.parent
DATA_DIR = BASE_DIR / "data"
DATA_DIR.mkdir(parents=True, exist_ok=True)
UPLOAD_DIR = DATA_DIR / "uploads"
UPLOAD_DIR.mkdir(parents=True, exist_ok=True)


def _load_dotenv() -> None:
    path = BASE_DIR / ".env"
    if not path.exists():
        return
    for line in path.read_text(encoding="utf-8").splitlines():
        line = line.strip()
        if not line or line.startswith("#") or "=" not in line:
            continue
        key, value = line.split("=", 1)
        os.environ.setdefault(key.strip(), value.strip().strip('"').strip("'"))


_load_dotenv()

DATABASE_URL = os.getenv("DATABASE_URL", f"sqlite:///{DATA_DIR / 'board.db'}")

AI_API_BASE = os.getenv("AI_API_BASE", "https://api.deepseek.com/v1").rstrip("/")
AI_API_KEY = os.getenv("AI_API_KEY", "")
AI_MODEL = os.getenv("AI_MODEL", "deepseek-chat")
AI_TEMPERATURE = float(os.getenv("AI_TEMPERATURE", "0.2"))
AI_TIMEOUT = float(os.getenv("AI_TIMEOUT", "90"))

PORT = int(os.getenv("PORT", "8770"))

# 首次启动自动创建的管理员账号（务必上线后改掉密码）
ADMIN_USERNAME = os.getenv("ADMIN_USERNAME", "admin").strip() or "admin"
ADMIN_PASSWORD = os.getenv("ADMIN_PASSWORD", "admin123").strip() or "admin123"
# 登录态有效天数
SESSION_DAYS = int(os.getenv("SESSION_DAYS", "30"))

# DEV=1 启动时开启开发模式（代码热加载 + 浏览器自动刷新）
DEV = os.getenv("DEV", "").strip().lower() in ("1", "true", "yes", "on")

# 允许在页面上被覆盖的 AI 配置键
AI_SETTING_KEYS = ("ai_api_base", "ai_api_key", "ai_model", "ai_temperature")

DEFAULT_AI_SETTINGS = {
    "ai_api_base": AI_API_BASE,
    "ai_api_key": AI_API_KEY,
    "ai_model": AI_MODEL,
    "ai_temperature": str(AI_TEMPERATURE),
}