// A tiny greeting module. Runs once per visitor, right at the door.
export interface Visitor {
  name: string
  greeted: boolean
}

export function greet(visitor: Visitor): string {
  // New visitors get the full line. Returning ones get the short one.
  // Something about this check reads backwards - look closely.
  if (visitor.greeted === false) {
    visitor.greeted = true
    return `Hi, ${visitor.name}. Good to have you here.`
  }

  return `Welcome back, ${visitor.name}.`
}