"""
Self-hosted settings for KeepItGoing.

Use this for users running their own instance.
"""

import os
import sys
import dj_database_url
from .base import *

# Security
SECRET_KEY = os.environ.get('SECRET_KEY')
if not SECRET_KEY:
    raise ValueError(
        "SECRET_KEY environment variable is required for self-hosted deployment. "
        "Generate one with: python -c \"from django.core.management.utils import get_random_secret_key; print(get_random_secret_key())\""
    )

# Validate SECRET_KEY strength
if len(SECRET_KEY) < 50:
    print("WARNING: SECRET_KEY is too short. Use at least 50 characters for security.", file=sys.stderr)

DEBUG = os.environ.get('DEBUG', 'False').lower() == 'true'

# Force DEBUG to False in self-hosted mode for security
if DEBUG:
    print("WARNING: DEBUG=True in self-hosted mode is a security risk!", file=sys.stderr)

ALLOWED_HOSTS = os.environ.get('ALLOWED_HOSTS', 'localhost,127.0.0.1').split(',')

# Database - Support both PostgreSQL and MariaDB/MySQL via DATABASE_URL
# DATABASE_URL format examples:
#   PostgreSQL: postgresql://user:password@host:5432/dbname
#   MariaDB/MySQL: mysql://user:password@host:3306/dbname
database_url = os.environ.get('DATABASE_URL')

if database_url:
    # Use DATABASE_URL for flexible database backend (PostgreSQL, MariaDB, MySQL, etc.)
    DATABASES = {
        'default': dj_database_url.config(
            default=database_url,
            conn_max_age=600,
            conn_health_checks=True,
        )
    }

    # Add MariaDB/MySQL specific options if using MySQL backend
    if 'mysql' in database_url.lower():
        DATABASES['default']['OPTIONS'] = {
            'charset': 'utf8mb4',
            'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",
        }
else:
    # Fallback to manual configuration (backwards compatibility)
    # Supports both PostgreSQL and MariaDB/MySQL
    db_engine = os.environ.get('DB_ENGINE', 'django.db.backends.postgresql')

    DATABASES = {
        'default': {
            'ENGINE': db_engine,
            'NAME': os.environ.get('DB_NAME', os.environ.get('POSTGRES_DB', 'keepitgoing')),
            'USER': os.environ.get('DB_USER', os.environ.get('POSTGRES_USER', 'keepitgoing')),
            'PASSWORD': os.environ.get('DB_PASSWORD', os.environ.get('POSTGRES_PASSWORD', 'keepitgoing')),
            'HOST': os.environ.get('DB_HOST', os.environ.get('POSTGRES_HOST', 'db')),
            'PORT': os.environ.get('DB_PORT', os.environ.get('POSTGRES_PORT', '5432')),
        }
    }

    # Add MariaDB/MySQL specific options if using MySQL backend
    if 'mysql' in db_engine:
        DATABASES['default']['OPTIONS'] = {
            'charset': 'utf8mb4',
            'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",
        }

# Redis/Celery
REDIS_URL = os.environ.get('REDIS_URL', 'redis://redis:6379/0')
CELERY_BROKER_URL = REDIS_URL
CELERY_RESULT_BACKEND = REDIS_URL

# Cache
CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.redis.RedisCache',
        'LOCATION': REDIS_URL,
    }
}

# CORS - configurable for self-hosted
CORS_ALLOWED_ORIGINS = os.environ.get(
    'CORS_ALLOWED_ORIGINS',
    'http://localhost:8000'
).split(',')

# CSRF - configurable for self-hosted
# Must include the exact URL (with protocol and port) you're accessing the site from
CSRF_TRUSTED_ORIGINS = os.environ.get(
    'CSRF_TRUSTED_ORIGINS',
    'http://localhost:8000'
).split(',')

# ===================================================================
# Security Settings
# ===================================================================

# SSL/HTTPS Security
# Note: SSL termination, HTTP→HTTPS redirect, and HSTS are handled by Nginx Proxy Manager
# NPM is configured with: Force SSL = On, HSTS Enabled = On
SECURE_SSL_REDIRECT = False  # NPM handles HTTP→HTTPS redirect
SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')  # Trust NPM's X-Forwarded-Proto header

# HSTS - Disabled in Django since NPM sends HSTS headers
# NPM is configured to send: Strict-Transport-Security: max-age=31536000
# Enabling here would create duplicate headers
SECURE_HSTS_SECONDS = 0  # Disabled - NPM handles HSTS

# Silence Django security warnings for settings handled by Nginx Proxy Manager
# W004: HSTS - NPM sends Strict-Transport-Security headers
# W008: SSL Redirect - NPM redirects HTTP to HTTPS
SILENCED_SYSTEM_CHECKS = [
    'security.W004',  # HSTS handled by NPM
    'security.W008',  # SSL redirect handled by NPM
]

# Cookie Security
# These are still needed even though NPM handles SSL
SESSION_COOKIE_SECURE = True  # Only send session cookies over HTTPS
CSRF_COOKIE_SECURE = True     # Only send CSRF cookies over HTTPS
CSRF_COOKIE_HTTPONLY = True   # Prevent JavaScript access to CSRF cookie
SESSION_COOKIE_HTTPONLY = True  # Prevent JavaScript access to session cookie

# Additional Security Headers
# Note: All security headers are now configured in Nginx Proxy Manager
# This includes: CSP, X-Content-Type-Options, X-XSS-Protection, Referrer-Policy, Permissions-Policy
# X-Frame-Options still set here for defense-in-depth
X_FRAME_OPTIONS = 'DENY'  # Prevent clickjacking

# Static files
STATICFILES_STORAGE = 'whitenoise.storage.CompressedManifestStaticFilesStorage'

# Email - configurable
EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST = os.environ.get('EMAIL_HOST', '')
EMAIL_PORT = int(os.environ.get('EMAIL_PORT', 587))
EMAIL_HOST_USER = os.environ.get('EMAIL_HOST_USER', '')
EMAIL_HOST_PASSWORD = os.environ.get('EMAIL_HOST_PASSWORD', '')
EMAIL_USE_TLS = os.environ.get('EMAIL_USE_TLS', 'True').lower() == 'true'
DEFAULT_FROM_EMAIL = os.environ.get('DEFAULT_FROM_EMAIL', 'noreply@localhost')

# Self-hosted mode - no billing
SAAS_MODE = False
BILLING_ENABLED = False
USAGE_LIMITS_ENABLED = False

# Logging
LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'verbose': {
            'format': '{levelname} {asctime} {module} {message}',
            'style': '{',
        },
    },
    'handlers': {
        'console': {
            'class': 'logging.StreamHandler',
            'formatter': 'verbose',
        },
    },
    'root': {
        'handlers': ['console'],
        'level': 'INFO',
    },
}