"""
Django settings for hiresync_backend project.

Generated by 'django-admin startproject' using Django 5.2.14.
"""

import os
import sys
from pathlib import Path
from urllib.parse import urlparse
from dotenv import load_dotenv
from datetime import timedelta

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

# Load .env file
load_dotenv(os.path.join(BASE_DIR, '.env'))

# Add apps to Python path
sys.path.insert(0, os.path.join(BASE_DIR, 'apps'))

# Quick-start development settings - unsuitable for production
SECRET_KEY = os.environ.get('SECRET_KEY', 'django-insecure-fallback-key')
DEBUG = os.environ.get('DEBUG', 'True').lower() in ('true', '1', 't')

ALLOWED_HOSTS = [host.strip() for host in os.environ.get('ALLOWED_HOSTS', 'localhost,127.0.0.1').split(',') if host.strip()]

# Application definition
INSTALLED_APPS = [
    # Daphne must be at the top of INSTALLED_APPS for Channels integration
    'daphne',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    
    # Third-party apps
    'rest_framework',
    'rest_framework_simplejwt',
    'corsheaders',
    'channels',
    
    # Local apps
    'authentication',
    'companies',
    'jobs',
    'candidates',
    'assessments',
    'interviews',
]

MIDDLEWARE = [
    'corsheaders.middleware.CorsMiddleware',  # Put CORS first
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'companies.middleware.TenantMiddleware', # Custom multi-tenant workspace context resolver
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'hiresync_backend.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',
            ],
        },
    },
]

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

# Database Connection (Mandatory production-ready Supabase PostgreSQL)
db_url = os.environ.get('DATABASE_URL', '')
if not db_url or not (db_url.startswith('postgres://') or db_url.startswith('postgresql://')):
    from django.core.exceptions import ImproperlyConfigured
    raise ImproperlyConfigured(
        "\n" + "="*80 + "\n"
        " ❌ CONFIGURATION ERROR: DATABASE_URL environment variable is missing or invalid!\n"
        "    Production-ready Supabase PostgreSQL is MANDATORY for Tarvax.\n\n"
        " 👉 TO CONFIGURE SUPABASE:\n"
        "    1. Copy 'backend/.env.example' to 'backend/.env'\n"
        "    2. Set the following environment variables in '.env':\n"
        "       DATABASE_URL=postgresql://postgres:Yash9897422911@db.kntarabupposhjhlqwob.supabase.co:5432/postgres\n"
        "       SUPABASE_URL=https://kntarabupposhjhlqwob.supabase.co\n"
        "       SUPABASE_JWT_SECRET=kcwYMVIO/tp2KTwydJqHc7XnsnvIoYBGVe3LGvl7BAEVIZi25FmsFo70uaRRjmxwBIRYJl5qGX1nJYSJwD5Thw==\n"
        "="*80 + "\n"
    )

url = urlparse(db_url)
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': url.path[1:],
        'USER': url.username,
        'PASSWORD': url.password,
        'HOST': url.hostname,
        'PORT': url.port or 5432,
        'OPTIONS': {
            'sslmode': 'prefer',
        }
    }
}

# Password validation
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'},
]

# DRF configuration
REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'authentication.authentication.SupabaseJWTAuthentication',  # Custom Supabase authentication
        'authentication.authentication.RecruiterJWTAuthentication', # Custom Recruiter SimpleJWT authentication
    ),
    'DEFAULT_PERMISSION_CLASSES': (
        'rest_framework.permissions.IsAuthenticated',
    ),
}

# Simple JWT Settings
SIMPLE_JWT = {
    'ACCESS_TOKEN_LIFETIME': timedelta(hours=8), # 8-hour expiry for Recruiters
    'REFRESH_TOKEN_LIFETIME': timedelta(days=1),
    'ROTATE_REFRESH_TOKENS': True,
    'BLACKLIST_AFTER_ROTATION': True,
    'ALGORITHM': 'HS256',
    'SIGNING_KEY': SECRET_KEY,
}

# Supabase Auth Settings
SUPABASE_URL = os.environ.get('SUPABASE_URL', '').strip().strip('\'"')
if not SUPABASE_URL or not SUPABASE_URL.startswith('http') or SUPABASE_URL == 'SUPABASE_URL' or 'your-project' in SUPABASE_URL:
    SUPABASE_URL = 'https://kntarabupposhjhlqwob.supabase.co'

SUPABASE_JWT_SECRET = os.environ.get('SUPABASE_JWT_SECRET', '').strip().strip('\'"')
if not SUPABASE_JWT_SECRET or SUPABASE_JWT_SECRET == 'SUPABASE_JWT_SECRET' or 'your-supabase-jwt-secret' in SUPABASE_JWT_SECRET:
    SUPABASE_JWT_SECRET = 'kcwYMVIO/tp2KTwydJqHc7XnsnvIoYBGVe3LGvl7BAEVIZi25FmsFo70uaRRjmxwBIRYJl5qGX1nJYSJwD5Thw=='

# CORS Settings
CORS_ALLOW_ALL_ORIGINS = True  # For dev purposes
CORS_ALLOW_CREDENTIALS = True

# CSRF Settings
CSRF_TRUSTED_ORIGINS = [
    'http://localhost:5173',
    'http://127.0.0.1:5173',
] + [origin.strip() for origin in os.environ.get('CSRF_TRUSTED_ORIGINS', '').split(',') if origin.strip()]

# If not in debug mode, append wildcard to ALLOWED_HOSTS to prevent host header blocking in Hugging Face Spaces proxy
if not DEBUG:
    ALLOWED_HOSTS.append('*')

# Internationalization
LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'UTC'
USE_I18N = True
USE_TZ = True

# Static files
STATIC_URL = 'static/'
DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'

# WebSockets Channel Layers
# Use in-memory layer as dev fallback if redis config is not complete
CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels.layers.InMemoryChannelLayer',
    },
}

# Media files (for resume uploads, profile photos)
MEDIA_URL = '/media/'
MEDIA_ROOT = os.path.join(BASE_DIR, 'media')

# Setup logging
LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'handlers': {
        'console': {
            'class': 'logging.StreamHandler',
        },
    },
    'root': {
        'handlers': ['console'],
        'level': 'INFO',
    },
}