import * as env from 'env-var';
import {urlJoin} from './helpers/urlJoin';

const NODE_ENV = env.get('NODE_ENV').default('development').asString();
const isProduction = NODE_ENV === 'production';

const envs = {
	NODE_ENV,
	// port of the server
	PORT: env.get('PORT').default('3000').asPortNumber(),
	// hostname of the server ('0.0.0.0' listens on all network interfaces)
	HOSTNAME: env.get('HOSTNAME').default('0.0.0.0').asString(),
	// base path
	BASE_PATH: env.get('BASE_PATH').default('/').asString(),
	// external base url
	EXTERNAL_BASE_URL: env.get('EXTERNAL_BASE_URL').asString(),

	// url of redis session store (required in production using InMemory)
	REDIS_URL: env.get('REDIS_URL').asString() || undefined,
	// cookie secret for the session id (required in production using Session)
	SESSION_SECRET: env.get('SESSION_SECRET').asString() || undefined,

	// header where user info token is stored to request auth proxy
	USERINFO_HEADER: env.get('USERINFO_HEADER').default('X-Userinfo-Token').asString(),
	// header when user info token expires (seconds after 01/01/1970)
	EXPIRE_HEADER: env.get('EXPIRE_HEADER').default('X-Userinfo-Expire').asString(),
	// base url to init a logout or request user info
	AUTH_PROXY_URL: env.get('AUTH_PROXY_URL').asString() || undefined,
	// override AUTH_PROXY_URL to request user info
	AUTH_PROXY_USERINFO_URL: env.get('AUTH_PROXY_USERINFO_URL').asString() || undefined,
	// override AUTH_PROXY_URL to init a logout
	AUTH_PROXY_INIT_LOGOUT_URL: env.get('AUTH_PROXY_INIT_LOGOUT_URL').asString() || undefined,
};

function requireEnv(name: string, onlyInProduction = false): void {
	env.get(name).required(!onlyInProduction || isProduction).asString();
}

export const DefaultConfig = {
	...envs,
		EXTERNAL_BASE_URL:
			envs.EXTERNAL_BASE_URL ||
			urlJoin(`http://${envs.HOSTNAME}${envs.PORT !== 80 ? `:${envs.PORT}` : ''}`, envs.BASE_PATH),
	isProduction,
	requireEnv,
	AUTH_PROXY_USERINFO_URL: envs.AUTH_PROXY_USERINFO_URL ||
		envs.AUTH_PROXY_URL && urlJoin(envs.AUTH_PROXY_URL, 'userinfo'),
	AUTH_PROXY_INIT_LOGOUT_URL: envs.AUTH_PROXY_INIT_LOGOUT_URL ||
		envs.AUTH_PROXY_URL && urlJoin(envs.AUTH_PROXY_URL, 'init-logout'),
};