"""Shared Django settings for all environments."""

import json
import os
from pathlib import Path
from urllib.parse import urlparse

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


def env(key: str, default: str | None = None) -> str | None:
    return os.environ.get(key, default)


def env_bool(key: str, default: bool = False) -> bool:
    value = os.environ.get(key)
    if value is None:
        return default
    return value.lower() in {"1", "true", "yes", "on"}


def env_list(key: str, default: str = "") -> list[str]:
    value = os.environ.get(key, default)
    if not value:
        return []
    value = value.strip()
    if value.startswith("["):
        try:
            parsed = json.loads(value)
        except ValueError:
            parsed = None
        if isinstance(parsed, list):
            return [str(item).strip() for item in parsed if str(item).strip()]
    return [item.strip() for item in value.split(",") if item.strip()]


def database_config() -> dict:
    database_url = env("DATABASE_URL")
    if database_url:
        parsed = urlparse(database_url)
        return {
            "default": {
                "ENGINE": "django.db.backends.postgresql",
                "NAME": parsed.path.lstrip("/"),
                "USER": parsed.username or "",
                "PASSWORD": parsed.password or "",
                "HOST": parsed.hostname or "",
                "PORT": str(parsed.port or 5432),
            }
        }

    if env("DB_HOST"):
        return {
            "default": {
                "ENGINE": "django.db.backends.postgresql",
                "NAME": env("DB_NAME", "scha"),
                "USER": env("DB_USER", "scha"),
                "PASSWORD": env("DB_PASSWORD", ""),
                "HOST": env("DB_HOST"),
                "PORT": env("DB_PORT", "5432"),
            }
        }

    return {
        "default": {
            "ENGINE": "django.db.backends.sqlite3",
            "NAME": BASE_DIR / "db.sqlite3",
        }
    }


def build_csrf_trusted_origins(
    allowed_hosts: list[str], explicit: list[str] | None = None
) -> list[str]:
    """Build CSRF_TRUSTED_ORIGINS for Django 4+ Origin checks on HTTPS POSTs."""
    if explicit:
        return explicit

    local_hosts = {"localhost", "127.0.0.1", "0.0.0.0"}
    origins: list[str] = []
    for host in allowed_hosts:
        if not host or host == "*" or host.startswith("."):
            continue
        hostname = host.split(":")[0]
        scheme = "http" if hostname in local_hosts else "https"
        origins.append(f"{scheme}://{host}")
    return origins


SECRET_KEY = env(
    "DJANGO_SECRET_KEY",
    "django-insecure-dev-only-change-me-before-production",
)

DEBUG = env_bool("DJANGO_DEBUG", False)

allowed_hosts = env_list("DJANGO_ALLOWED_HOSTS", "*")
ALLOWED_HOSTS = allowed_hosts if allowed_hosts else ["*"]

CSRF_TRUSTED_ORIGINS = build_csrf_trusted_origins(
    ALLOWED_HOSTS,
    env_list("DJANGO_CSRF_TRUSTED_ORIGINS"),
)

INSTALLED_APPS = [
    "schasite.apps.SchasiteConfig",
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "whitenoise.runserver_nostatic",
    "django.contrib.staticfiles",
    "phonenumber_field",
    "django_recaptcha",
]

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 = "scha.urls"

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

WSGI_APPLICATION = "scha.wsgi.application"

DATABASES = database_config()

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 = "en-us"
TIME_ZONE = "UTC"
USE_I18N = True
USE_TZ = True

STATIC_URL = "static/"
STATIC_ROOT = BASE_DIR / "staticfiles"
STORAGES = {
    "staticfiles": {
        "BACKEND": "whitenoise.storage.CompressedManifestStaticFilesStorage",
    },
}

DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"

STRIPE_PUBLISHABLE_KEY = env("STRIPE_PUBLISHABLE_KEY", "")
STRIPE_SECRET_KEY = env("STRIPE_SECRET_KEY", "")
STRIPE_ENDPOINT_SECRET = env("STRIPE_ENDPOINT_SECRET", "")

RECAPTCHA_PUBLIC_KEY = env("RECAPTCHA_PUBLIC_KEY", "")
RECAPTCHA_PRIVATE_KEY = env("RECAPTCHA_PRIVATE_KEY", "")