import type { Note, ShareInvitation } from '@/types'

export interface SSEHandlers {
  onNoteCreated: (note: Note) => void
  onNoteUpdated: (note: Note) => void
  onNoteDeleted: (data: { id: string }) => void
  onInvitationReceived?: (invitation: ShareInvitation) => void
  onError: (err: Event) => void
}

export function createSSEClient(url: string, handlers: SSEHandlers): { close: () => void } {
  const eventSource = new EventSource(url)

  eventSource.addEventListener('note_created', (event: MessageEvent) => {
    try {
      const note: Note = JSON.parse(event.data)
      handlers.onNoteCreated(note)
    } catch {
      handlers.onError(new Event('parse_error'))
    }
  })

  eventSource.addEventListener('note_updated', (event: MessageEvent) => {
    try {
      const note: Note = JSON.parse(event.data)
      handlers.onNoteUpdated(note)
    } catch {
      handlers.onError(new Event('parse_error'))
    }
  })

  eventSource.addEventListener('note_deleted', (event: MessageEvent) => {
    try {
      const data: { id: string } = JSON.parse(event.data)
      handlers.onNoteDeleted(data)
    } catch {
      handlers.onError(new Event('parse_error'))
    }
  })

  eventSource.addEventListener('invitation_received', (event: MessageEvent) => {
    try {
      const raw = JSON.parse(event.data)
      const invitation: ShareInvitation = {
        id: raw.id,
        fromPublicKey: raw.from_public_key,
        toPublicKey: raw.to_public_key,
        encryptedGroupKey: raw.encrypted_group_key,
        iv: raw.iv,
        noteId: raw.note_id,
        noteTitle: raw.note_title,
        created_at: raw.created_at,
      }
      handlers.onInvitationReceived?.(invitation)
    } catch {
      handlers.onError(new Event('parse_error'))
    }
  })

  eventSource.onerror = (err: Event) => {
    handlers.onError(err)
  }

  return {
    close: () => eventSource.close(),
  }
}