import os
from pathlib import Path
import environ

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

env = environ.Env(
    DEBUG=(bool, True),
    ALLOWED_HOSTS=(list, ['*']),
    CSRF_TRUSTED_ORIGINS=(list, ['*']),
)

# Read .env if present
environ.Env.read_env(BASE_DIR / '.env')

SECRET_KEY = env('SECRET_KEY', default='dev-secret-key-change-in-production-please-12345')
DEBUG = env('DEBUG')
ALLOWED_HOSTS = env('ALLOWED_HOSTS')
CSRF_TRUSTED_ORIGINS = env('CSRF_TRUSTED_ORIGINS')

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'channels',
    'core',
]

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 = 'config.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [BASE_DIR / 'templates'],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'core.context_processors.sidebar_context',
                'core.context_processors.sidebar_context',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'config.wsgi.application'
ASGI_APPLICATION = 'config.asgi.application'

# Database
DATABASE_URL = env('DATABASE_URL', default=f'sqlite:///{BASE_DIR}/db.sqlite3')
if DATABASE_URL.startswith('sqlite'):
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': BASE_DIR / 'db.sqlite3',
        }
    }
else:
    import dj_database_url
    DATABASES = {'default': dj_database_url.config(default=DATABASE_URL, conn_max_age=600)}

# Channels / Redis
REDIS_URL = env('REDIS_URL', default=None)
if REDIS_URL:
    CHANNEL_LAYERS = {
        'default': {
            'BACKEND': 'channels_redis.core.RedisChannelLayer',
            'CONFIG': {'hosts': [REDIS_URL]},
        }
    }
else:
    CHANNEL_LAYERS = {
        'default': {
            'BACKEND': 'channels.layers.InMemoryChannelLayer',
        }
    }

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'
STATICFILES_DIRS = [BASE_DIR / 'static']
STATICFILES_STORAGE = 'whitenoise.storage.CompressedManifestStaticFilesStorage'

DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
LOGIN_URL = '/login/'
LOGIN_REDIRECT_URL = '/'
LOGOUT_REDIRECT_URL = '/login/'

# Production security (applied when DEBUG=False)
if not DEBUG:
    SECURE_SSL_REDIRECT = True
    SECURE_HSTS_SECONDS = 31536000
    SECURE_HSTS_INCLUDE_SUBDOMAINS = True
    SESSION_COOKIE_SECURE = True
    CSRF_COOKIE_SECURE = True
    SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')