from pathlib import Path
import os
from django.core.exceptions import ImproperlyConfigured


BASE_DIR = Path(__file__).resolve().parent.parent


def env_bool(name: str, default: bool = False) -> bool:
    return os.getenv(name, str(default)).lower() in {"1", "true", "yes", "on"}


SECRET_KEY = os.getenv("SECRET_KEY", "development-only-change-me")
DEBUG = env_bool("DEBUG", True)
if not DEBUG and SECRET_KEY == "development-only-change-me":
    raise ImproperlyConfigured("SECRET_KEY muss im Produktionsbetrieb gesetzt sein.")
ALLOWED_HOSTS = [value.strip() for value in os.getenv("ALLOWED_HOSTS", "localhost,127.0.0.1").split(",") if value.strip()]
CSRF_TRUSTED_ORIGINS = [value.strip() for value in os.getenv("CSRF_TRUSTED_ORIGINS", "").split(",") if value.strip()]

INSTALLED_APPS = [
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    "rest_framework",
    "rest_framework_api_key",
    "inventory",
]

MIDDLEWARE = [
    "django.middleware.security.SecurityMiddleware",
    "whitenoise.middleware.WhiteNoiseMiddleware",
    "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",
]

ROOT_URLCONF = "csr_inventory.urls"
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",
                "inventory.context_processors.navigation_context",
            ],
        },
    }
]
WSGI_APPLICATION = "csr_inventory.wsgi.application"

DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.postgresql",
        "NAME": os.getenv("POSTGRES_DB", "csr_inventory"),
        "USER": os.getenv("POSTGRES_USER", "csr_inventory"),
        "PASSWORD": os.getenv("POSTGRES_PASSWORD", ""),
        "HOST": os.getenv("POSTGRES_HOST", "localhost"),
        "PORT": os.getenv("POSTGRES_PORT", "5432"),
        "CONN_MAX_AGE": 60,
        "OPTIONS": {"connect_timeout": 5},
    }
}

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"},
]

LANGUAGE_CODE = "de-de"
TIME_ZONE = os.getenv("TIME_ZONE", "Europe/Berlin")
USE_I18N = True
USE_TZ = True
STATIC_URL = "/static/"
STATIC_ROOT = BASE_DIR / "staticfiles"
MEDIA_URL = "/media/"
MEDIA_ROOT = BASE_DIR / "media"
DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
LOGIN_URL = "login"
LOGIN_REDIRECT_URL = "inventory:device-list"
LOGOUT_REDIRECT_URL = "login"
DATA_UPLOAD_MAX_MEMORY_SIZE = int(os.getenv("MAX_UPLOAD_SIZE", str(10 * 1024 * 1024)))
FILE_UPLOAD_MAX_MEMORY_SIZE = DATA_UPLOAD_MAX_MEMORY_SIZE

SECURE_PROXY_SSL_HEADER = ("HTTP_X_FORWARDED_PROTO", "https")
SESSION_COOKIE_SECURE = env_bool("SECURE_COOKIES", not DEBUG)
CSRF_COOKIE_SECURE = env_bool("SECURE_COOKIES", not DEBUG)
SESSION_COOKIE_HTTPONLY = True
SESSION_COOKIE_SAMESITE = "Lax"
CSRF_COOKIE_HTTPONLY = False
CSRF_COOKIE_SAMESITE = "Lax"
SECURE_CONTENT_TYPE_NOSNIFF = True
SECURE_REFERRER_POLICY = "same-origin"
X_FRAME_OPTIONS = "DENY"
SECURE_HSTS_SECONDS = 31536000 if not DEBUG else 0
SECURE_HSTS_INCLUDE_SUBDOMAINS = not DEBUG
SECURE_HSTS_PRELOAD = not DEBUG
SECURE_SSL_REDIRECT = env_bool("SECURE_SSL_REDIRECT", not DEBUG)

STORAGES = {
    "default": {"BACKEND": "django.core.files.storage.FileSystemStorage"},
    "staticfiles": {
        "BACKEND": "django.contrib.staticfiles.storage.StaticFilesStorage" if DEBUG
        else "whitenoise.storage.CompressedManifestStaticFilesStorage"
    },
}

# Die API verwendet absichtlich keine Browser-Sitzung. Ohne einen gültigen,
# widerrufbaren API-Schlüssel wird jede API-Anfrage abgewiesen.
REST_FRAMEWORK = {
    "DEFAULT_AUTHENTICATION_CLASSES": ["inventory.api_auth.InventoryAPIKeyAuthentication"],
    "DEFAULT_PERMISSION_CLASSES": ["inventory.api_auth.InventoryAPIPermission"],
    "DEFAULT_RENDERER_CLASSES": ["rest_framework.renderers.JSONRenderer"],
    "DEFAULT_PARSER_CLASSES": ["rest_framework.parsers.JSONParser"],
    "DEFAULT_PAGINATION_CLASS": "inventory.api_pagination.PagedDeviceResults",
    "PAGE_SIZE": 50,
    "DEFAULT_THROTTLE_CLASSES": [
        "rest_framework.throttling.AnonRateThrottle",
        "inventory.api_auth.APIClientRateThrottle",
    ],
    "DEFAULT_THROTTLE_RATES": {
        "anon": os.getenv("API_ANON_RATE", "20/min"),
        "api_client": os.getenv("API_CLIENT_RATE", "300/min"),
    },
}

LOGGING = {
    "version": 1,
    "disable_existing_loggers": False,
    "formatters": {"standard": {"format": "{levelname} {asctime} {name}: {message}", "style": "{"}},
    "handlers": {"console": {"class": "logging.StreamHandler", "formatter": "standard"}},
    "root": {"handlers": ["console"], "level": os.getenv("LOG_LEVEL", "WARNING")},
}