type SessionInfo = {
  id?: string
  parentID?: string
}

export function createFirstMessageVariantGate() {
  const pending = new Set<string>()

  return {
    markSessionCreated(info?: SessionInfo) {
      if (info?.id && !info.parentID) {
        pending.add(info.id)
      }
    },
    shouldOverride(sessionID?: string) {
      if (!sessionID) return false
      return pending.has(sessionID)
    },
    markApplied(sessionID?: string) {
      if (!sessionID) return
      pending.delete(sessionID)
    },
    clear(sessionID?: string) {
      if (!sessionID) return
      pending.delete(sessionID)
    },
  }
}