import os

def require(key: str) -> str:
  value = os.environ.get(key)
  if not value:
    raise RuntimeError(f"Required environment variable {key} is not set")
  return value

def optional(key: str, default: str = "") -> str:
  return os.environ.get(key, default)

# Required
JWT_SECRET_KEY = require("JWT_SECRET_KEY")
DATABASE_URL   = require("DATABASE_URL")
RESEND_API_KEY = require("RESEND_API_KEY")
EMAIL_FROM     = require("EMAIL_FROM")

# Optional with sensible defaults for local dev
FRONTEND_URL      = optional("FRONTEND_URL", "http://localhost:5173")
CORS_ORIGINS      = optional("CORS_ORIGINS", "http://localhost:5173").split(",")
WIKIRANK_USER_AGENT = optional("WIKIRANK_USER_AGENT", "WikiTCG/1.0")