import type { MessageResource } from '../types'

export interface PeopleSystemMessageResource extends MessageResource {
  systemTextFormat: 'people'
  systemTextParts: { names: string[]; overflowCount: number; action: string }
  personIdsForSystemEvent: number[]
}

export interface ActorSystemMessageResource extends MessageResource {
  systemTextFormat: 'actor'
  text: string
}

export type SystemMessageResource = PeopleSystemMessageResource | ActorSystemMessageResource

export const isSystemMessage = (message: MessageResource): message is SystemMessageResource => {
  switch (message.systemTextFormat) {
    case 'people':
      return message.systemTextParts != null && message.personIdsForSystemEvent != null
    case 'actor':
      return !!message.text
    default:
      return false
  }
}