/**
 * Y.js collaboration provider for rNotes
 *
 * Wraps y-websocket's WebsocketProvider to connect to the y-websocket
 * sidecar server for real-time collaborative editing.
 */

import * as Y from 'yjs'
import { WebsocketProvider } from 'y-websocket'

const COLLAB_WS_URL = process.env.NEXT_PUBLIC_COLLAB_WS_URL || 'ws://localhost:1234'

export interface CollabState {
  connected: boolean
  synced: boolean
  peerCount: number
}

export function createCollabProvider(
  noteId: string,
  ydoc: Y.Doc,
  user: { name: string; color: string },
  onStateChange?: (state: CollabState) => void,
): WebsocketProvider {
  const roomName = `note-${noteId}`
  const provider = new WebsocketProvider(COLLAB_WS_URL, roomName, ydoc)

  // Set local awareness (cursor name/color)
  provider.awareness.setLocalStateField('user', user)

  const emitState = () => {
    onStateChange?.({
      connected: provider.wsconnected,
      synced: provider.synced,
      peerCount: provider.awareness.getStates().size - 1,
    })
  }

  provider.on('status', emitState)
  provider.on('sync', emitState)
  provider.awareness.on('update', emitState)

  return provider
}