"""
基础配置：所有环境共享的部分。

具体环境差异：
- 开发：config.settings.dev（继承 base，DEBUG=True，SQLite）
- 生产：config.settings.prod（继承 base，DEBUG=False，PostgreSQL + Granian）
- 测试：config.settings.test（继承 base，内存 SQLite）
"""

from pathlib import Path
import environ

BASE_DIR = Path(__file__).resolve().parent.parent.parent  # backend/

env = environ.Env()
# 读取 backend/.env（若存在）
env_file = BASE_DIR / ".env"
if env_file.exists():
    environ.Env.read_env(str(env_file))


# === 核心 ===
SECRET_KEY = env(
    "DJANGO_SECRET_KEY",
    default="dev-insecure-change-me-IN-PROD-PLEASE",
)
DEBUG = False  # 必须在子模块覆盖
ALLOWED_HOSTS = ["*"]  # 子模块覆盖


# === 应用 ===
INSTALLED_APPS = [
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    # 第三方
    "rest_framework",
    "rest_framework_simplejwt",
    # 业务应用
    "apps.core",
    "apps.catalog",
    "apps.partner",
    "apps.inventory",
    "apps.finance",
    "apps.purchase",
    "apps.sales",
    "apps.report",
    "apps.channel",
    "apps.notify",
    "apps.openapi",
    "apps.printing",
    "apps.ai",
    "apps.billing",
    "apps.website",
    "apps.storefront",
]

MIDDLEWARE = [
    "django.middleware.security.SecurityMiddleware",
    "whitenoise.middleware.WhiteNoiseMiddleware",  # 前端静态资源同源托管
    "django.contrib.sessions.middleware.SessionMiddleware",
    "django.middleware.common.CommonMiddleware",
    "django.middleware.csrf.CsrfViewMiddleware",
    "django.contrib.auth.middleware.AuthenticationMiddleware",
    "django.contrib.messages.middleware.MessageMiddleware",
    "django.middleware.clickjacking.XFrameOptionsMiddleware",
    # 多租户识别
    "apps.core.context.RequestContextMiddleware",   # 请求上下文（审计用）
    "apps.core.middleware.TenantMiddleware",
    "apps.core.middleware.DemoReadOnlyMiddleware",
]

# Vue3 构建产物（dist）由 Django 同源服务：/static/* 托管资源，/ 返回 index.html
FRONTEND_DIST = BASE_DIR / "frontend_dist"  # 容器内：/app/frontend_dist
if not FRONTEND_DIST.exists():
    FRONTEND_DIST = BASE_DIR.parent / "frontend" / "dist"  # 本机开发：dealerhub/frontend/dist
STATICFILES_DIRS = [FRONTEND_DIST] if FRONTEND_DIST.exists() else []

ROOT_URLCONF = "config.urls"
ASGI_APPLICATION = "config.asgi.application"
WSGI_APPLICATION = "config.wsgi.application"

TEMPLATES = [
    {
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        "DIRS": [],
        "APP_DIRS": True,
        "OPTIONS": {
            "context_processors": [
                "django.template.context_processors.request",
                "django.contrib.auth.context_processors.auth",
                "django.contrib.messages.context_processors.messages",
            ],
        },
    },
]


# === 数据库（默认 SQLite，子模块可覆盖） ===
DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.sqlite3",
        "NAME": BASE_DIR / "db.sqlite3",
    }
}


# === 密码校验 ===
AUTH_PASSWORD_VALIDATORS = [
    {"NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator"},
    {"NAME": "django.contrib.auth.password_validation.MinimumLengthValidator"},
    {"NAME": "django.contrib.auth.password_validation.CommonPasswordValidator"},
    {"NAME": "django.contrib.auth.password_validation.NumericPasswordValidator"},
]
AUTH_USER_MODEL = "auth.User"  # 阶段 1 后改为 apps.authx.User


# === 本地化 ===
LANGUAGE_CODE = "zh-hans"
TIME_ZONE = "Asia/Shanghai"
USE_I18N = True
USE_TZ = True


# === 静态文件 ===
STATIC_URL = "static/"
STATIC_ROOT = BASE_DIR / "staticfiles"
MEDIA_URL = "media/"
MEDIA_ROOT = BASE_DIR / "media"

DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"


# === DRF ===
REST_FRAMEWORK = {
    "DEFAULT_AUTHENTICATION_CLASSES": (
        "rest_framework_simplejwt.authentication.JWTAuthentication",
        "rest_framework.authentication.SessionAuthentication",  # admin 用
    ),
    "DEFAULT_PERMISSION_CLASSES": (
        "rest_framework.permissions.IsAuthenticated",
        "apps.core.permissions.TenantMembershipPermission",
    ),
    "DEFAULT_PAGINATION_CLASS": "rest_framework.pagination.PageNumberPagination",
    "PAGE_SIZE": 20,
    "DATETIME_FORMAT": "%Y-%m-%d %H:%M:%S",
    # 统一业务异常 → HTTP 语义（迭代第 2 轮）；见 apps/core/exceptions.py
    "EXCEPTION_HANDLER": "apps.core.exceptions.api_exception_handler",
}


# === JWT ===
from datetime import timedelta  # noqa: E402

SIMPLE_JWT = {
    "ACCESS_TOKEN_LIFETIME": timedelta(hours=1),
    "REFRESH_TOKEN_LIFETIME": timedelta(days=30),
    "AUTH_HEADER_TYPES": ("Bearer",),
}


# === 日志 ===
LOGGING = {
    "version": 1,
    "disable_existing_loggers": False,
    "formatters": {
        "verbose": {
            "format": "[{asctime}] {levelname} {name}: {message}",
            "style": "{",
        },
    },
    "handlers": {
        "console": {
            "class": "logging.StreamHandler",
            "formatter": "verbose",
        },
    },
    "root": {
        "handlers": ["console"],
        "level": "INFO",
    },
    "loggers": {
        "django": {"handlers": ["console"], "level": "INFO", "propagate": False},
        "dealerhub": {"handlers": ["console"], "level": "DEBUG", "propagate": False},
    },
}


# === 多租户配置 ===
TENANT_HEADER = "X-Tenant-Id"
TENANT_DEFAULT = env("TENANT_DEFAULT", default="default")


# === AI 配置（批次 B） ===
# 无 KEY 时全部功能降级为纯统计版，不阻塞测试与演示。
AI_PROVIDER = env("AI_PROVIDER", default="")          # 空 = 未接 LLM，只跑统计引擎
AI_BASE_URL = env("AI_BASE_URL", default="https://api.openai.com/v1")
AI_API_KEY = env("AI_API_KEY", default="")
AI_MODEL = env("AI_MODEL", default="gpt-4o-mini")
AI_TIMEOUT = env.int("AI_TIMEOUT", default=20)
AI_FREE_MONTHLY_QUOTA = env.int("AI_FREE_MONTHLY_QUOTA", default=10)  # 0 = 不限