// Where to land after auth. The router guard stashes the intended destination
// in ?redirect=, and the login page reads it back; both go through this so a
// caller-controlled value can never send the user to an external origin.

const DEFAULT_DESTINATION = '/gardens'

/**
 * Return dest only if it is a same-origin absolute path (starts with a single
 * '/'); otherwise fall back to the gardens list. Rejects protocol-relative
 * ('//evil.com') and absolute ('https://…') URLs.
 */
export function safeRedirectPath(dest: string | undefined, fallback = DEFAULT_DESTINATION): string {
  return dest && dest.startsWith('/') && !dest.startsWith('//') ? dest : fallback
}