backend/expense_tracker/settings.py

"""
Django settings for expense_tracker project.

Generated by 'django-admin startproject' using Django 5.2.10.

For more information on this file, see
https://docs.djangoproject.com/en/5.2/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/5.2/ref/settings/
"""

from pathlib import Path
import os
from dotenv import load_dotenv

load_dotenv()

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/5.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = os.getenv('SECRET_KEY', 'django-insecure-ereyyk0#@t#lc$@hpx&9h@60-=-e+#=-3w^w+91w&ol-(6c(fv')

# FIX: InsecureKeyLengthWarning for JWT (needs 32 bytes)
# If the user-provided key is too short (e.g. 23 chars), we safely pad it for the runtime.
if len(SECRET_KEY) < 32:
    import logging
    print(f"WARNING: SECRET_KEY is too short ({len(SECRET_KEY)} chars). key_fix=True")
    # Pad with a consistent salt so it doesn't invalidate tokens on every restart if the base key is constant
    SECRET_KEY = SECRET_KEY.ljust(32, '-')

# SECURITY WARNING: don't run with debug turned on in production!
# SECURITY WARNING: don't run with debug turned on in production!
ENVIRONMENT = os.getenv('ENVIRONMENT', 'development')
DEBUG = os.getenv('DEBUG', 'False') == 'True'

# Combine the default hosts into a single string string
ALLOWED_HOSTS = os.getenv('ALLOWED_HOSTS', 'localhost,127.0.0.1,0.0.0.0,finmk.koyeb.app,finmk.onrender.com').split(',')
ALLOWED_HOSTS.append('.hf.space')
RENDER_EXTERNAL_HOSTNAME = os.environ.get('RENDER_EXTERNAL_HOSTNAME')

if RENDER_EXTERNAL_HOSTNAME:
    ALLOWED_HOSTS.append(RENDER_EXTERNAL_HOSTNAME)

# Always allow .onrender.com in production-like environments or if explicitly set
if ENVIRONMENT == 'production' or RENDER_EXTERNAL_HOSTNAME:
     ALLOWED_HOSTS.append('.koyeb.app') 
     ALLOWED_HOSTS.append('.onrender.com')

     # Render health checks sometimes use raw IPs or localhost, which are covered above.


# CSRF_TRUSTED_ORIGINS required for Render and Hugging Face
CSRF_TRUSTED_ORIGINS = [
     'https://finmk.koyeb.app',
    'https://finmk.onrender.com',
    'https://*.hf.space',
    'https://kumar715-finmk.hf.space'
]
if RENDER_EXTERNAL_HOSTNAME:
    CSRF_TRUSTED_ORIGINS.append(f'https://{RENDER_EXTERNAL_HOSTNAME}')


# Application definition


INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    # Third-party
    'rest_framework',
    'corsheaders',
    # Local
    'users',
    'finance',
    'analytics',
    'chatbot',
]

MIDDLEWARE = [
    'corsheaders.middleware.CorsMiddleware',
    '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 = 'expense_tracker.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [BASE_DIR / 'staticfiles'],
        '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 = 'expense_tracker.wsgi.application'

# Database
# HYBRID ARCHITECTURE:
# 1. 'default' (SQLite): Used ONLY for Django Admin, Auth, Sessions, ContentTypes.
#    Controlled by 'expense_tracker.db_router.AuthRouter'.
# 2. MongoDB (PyMongo): Used as the PRIMARY database for all application data (Users, Finance, Analytics).
#    Accessed directly via 'utils.MongoDBClient' and 'users.mongo_auth'.
#    NO Django ORM models are used for application data.

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}

DATABASE_ROUTERS = ['expense_tracker.db_router.AuthRouter']

# MongoDB Settings (Primary Data Source for App)
MONGODB_URI = os.getenv('MONGODB_URI', 'mongodb+srv://kumar:KumarDB7@mkcluster.hkk76.mongodb.net/finance')
MONGODB_SETTINGS = {
    'URI': MONGODB_URI,
    'DB_NAME': 'finance',
}


# Password validation
# https://docs.djangoproject.com/en/5.2/ref/settings/#auth-password-validators

# AUTH_PASSWORD_VALIDATORS commented out as we are in 100% MongoDB mode
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',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/5.2/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/5.2/howto/static-files/

STATIC_URL = '/static/'
STATIC_ROOT = BASE_DIR / 'staticfiles'

# Add frontend/dist to static files directories
STATICFILES_DIRS = []
if (BASE_DIR / '../frontend/dist').exists():
    STATICFILES_DIRS.append(BASE_DIR / '../frontend/dist')
# Docker build path
if (BASE_DIR / 'frontend_build').exists():
    STATICFILES_DIRS.append(BASE_DIR / 'frontend_build')

# Whitenoise configuration for serving static files
STATICFILES_STORAGE = 'whitenoise.storage.CompressedManifestStaticFilesStorage'

# Default primary key field type
# https://docs.djangoproject.com/en/5.2/ref/settings/#default-auto-field


# CORS Configuration
if DEBUG:
    CORS_ALLOW_ALL_ORIGINS = True
else:
    CORS_ALLOWED_ORIGINS = [
        "https://finmk.koyeb.app","https://finmk.onrender.com" # Update with your actual domain
    ]
    # Allow all subdomains for flexibility
    CORS_ALLOWED_ORIGIN_REGEXES = [
        r"^https://.*\.koyeb\.app$",
        r"^https://.*\.onrender\.com$",
        r"^https://.*\.hf\.space$"
    ]
    CORS_ALLOW_CREDENTIALS = True
# AUTH_USER_MODEL = 'users.User' # Custom user model (Disabled as we use MongoUser)

AUTHENTICATION_BACKENDS = [
    'users.mongo_auth.MongoBackend', # For App (MongoDB) - Primary
    'django.contrib.auth.backends.ModelBackend', # For Admin (SQLite) - Secondary
]

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'users.authentication.MongoJWTAuthentication', # For Mongo Users (App) - Priority
        'rest_framework_simplejwt.authentication.JWTAuthentication', # For SQLite Users (Admin)
    ),
    'DEFAULT_PERMISSION_CLASSES': [
        'rest_framework.permissions.IsAuthenticated',
    ],
}

from datetime import timedelta
SIMPLE_JWT = {
    'ACCESS_TOKEN_LIFETIME': timedelta(minutes=60),
    'REFRESH_TOKEN_LIFETIME': timedelta(days=1),
    'USER_ID_CLAIM': 'user_id',
}

# Database config moved to standard location above