from datetime import timedelta
from pathlib import Path
import os

BASE_DIR = Path(__file__).resolve().parent.parent
SECRET_KEY = os.environ.get("DJANGO_SECRET_KEY", "dev-insecure")
DEBUG = os.environ.get("DJANGO_DEBUG", "0" if os.environ.get("DJANGO_ENV") == "prod" else "1") == "1"
ALLOWED_HOSTS = [h.strip() for h in os.environ.get("DJANGO_ALLOWED_HOSTS", "*").split(",") if h.strip()]
if os.environ.get("DJANGO_ENV") == "prod":   # 生产 fail-fast：漏配即启动崩溃，不带病上线（raise 而非 assert，防 -O 剥离）
    if SECRET_KEY == "dev-insecure":
        raise RuntimeError("生产必须配置 DJANGO_SECRET_KEY")
    if not os.environ.get("DJANGO_ALLOWED_HOSTS"):
        raise RuntimeError("生产必须显式配置 DJANGO_ALLOWED_HOSTS")

INSTALLED_APPS = [
    "django.contrib.contenttypes",
    "django.contrib.auth",
    "corsheaders",
    "rest_framework",
    "tracker",
]
MIDDLEWARE = [
    "corsheaders.middleware.CorsMiddleware",
    "django.middleware.common.CommonMiddleware",
]
ROOT_URLCONF = "config.urls"
WSGI_APPLICATION = "config.wsgi.application"
TEMPLATES = [{
    "BACKEND": "django.template.backends.django.DjangoTemplates",
    "DIRS": [], "APP_DIRS": True, "OPTIONS": {"context_processors": []},
}]

if os.environ.get("DB_ENGINE", "mysql") == "sqlite":   # 本地无 MySQL 的开发模式
    DATABASES = {"default": {"ENGINE": "django.db.backends.sqlite3",
                             "NAME": BASE_DIR / "db.sqlite3"}}
else:
    DATABASES = {
        "default": {
            "ENGINE": "django.db.backends.mysql",
            "NAME": os.environ.get("DB_NAME", "tracker"),
            "USER": os.environ.get("DB_USER", "root"),
            "PASSWORD": os.environ.get("DB_PASSWORD", ""),
            "HOST": os.environ.get("DB_HOST", "127.0.0.1"),
            "PORT": os.environ.get("DB_PORT", "3306"),
            "OPTIONS": {"charset": "utf8mb4"},
        }
    }

REST_FRAMEWORK = {
    "DEFAULT_AUTHENTICATION_CLASSES": ("rest_framework_simplejwt.authentication.JWTAuthentication",),
    "DEFAULT_PERMISSION_CLASSES": ("rest_framework.permissions.IsAuthenticated",),
    "DEFAULT_THROTTLE_RATES": {"collect": "120/min", "admin": "600/min", "login": "10/min"},
    "NUM_PROXIES": 1,
}
SIMPLE_JWT = {"ACCESS_TOKEN_LIFETIME": timedelta(hours=12), "REFRESH_TOKEN_LIFETIME": timedelta(hours=24)}
CORS_ALLOW_ALL_ORIGINS = False
CACHES = {"default": {"BACKEND": "django.core.cache.backends.filebased.FileBasedCache",
                      "LOCATION": str(BASE_DIR / ".cache")}}   # 限流计数跨 gunicorn worker 共享（不共享则限额×3）
DATA_UPLOAD_MAX_MEMORY_SIZE = 262144                          # 256KB 应用层请求体兜底
TIME_ZONE = "Asia/Shanghai"
USE_TZ = True
LANGUAGE_CODE = "zh-hans"
DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
IP2REGION_XDB = str(BASE_DIR / "tracker" / "data" / "ip2region.xdb")