school_compare/backend/config.py

"""
Application configuration using pydantic-settings.
Loads from environment variables and .env file.
"""

import secrets
from pathlib import Path
from typing import List, Optional
from pydantic_settings import BaseSettings
from pydantic import Field


class Settings(BaseSettings):
    """Application settings loaded from environment."""

    # Paths
    data_dir: Path = Path(__file__).parent.parent / "data"
    frontend_dir: Path = Path(__file__).parent.parent / "frontend"

    # Server
    host: str = "0.0.0.0"
    port: int = 80
    debug: bool = False  # Set to False in production

    # Database
    database_url: str = "postgresql://schoolcompare:schoolcompare@localhost:5432/schoolcompare"

    # CORS - Production should only allow the actual domain
    allowed_origins: List[str] = ["https://schoolcompare.co.uk"]

    # API
    default_page_size: int = 50
    max_page_size: int = 100

    # Security
    admin_api_key: str = Field(default_factory=lambda: secrets.token_urlsafe(32))
    rate_limit_per_minute: int = 60  # Requests per minute per IP
    # A ceiling on total /api/ traffic, independent of any client identity.
    # client_key trusts headers only Cloudflare can vouch for, so a caller
    # reaching the origin directly could otherwise mint a fresh bucket per
    # request. See GlobalRateLimitMiddleware in backend/app.py.
    global_rate_limit_per_minute: int = 3000
    rate_limit_burst: int = 10  # Allow burst of requests
    max_request_size: int = 1024 * 1024  # 1MB max request size

    # Typesense
    typesense_url: str = "http://localhost:8108"
    typesense_api_key: str = ""

    # Feature flags (Unleash). An empty unleash_url disables flags entirely and
    # every flag evaluates False — the correct behaviour for local development
    # and CI, and the reason no test needs a running Unleash.
    unleash_url: str = ""
    unleash_api_token: str = ""
    unleash_app_name: str = "schoolcompare-backend"
    # On a named volume, so a restart during an Unleash outage keeps
    # last-known state instead of reverting a released feature to dark.
    unleash_cache_directory: str = "/app/.unleash"

    # Analytics
    ga_measurement_id: Optional[str] = "G-J0PCVT14NY"  # Google Analytics 4 Measurement ID

    class Config:
        env_file = ".env"
        env_file_encoding = "utf-8"
        extra = "ignore"


# Singleton instance
settings = Settings()