//
//  CommunicationProvider.swift
//  Peered
//
//  Created by Oskar Chybowski on 11/05/2025.
//

import Foundation
import MultipeerConnectivity

@Observable
final class CommunicationProvider: NSObject, MCNearbyServiceBrowserDelegate {
  private let session: MCSession
  private let browser: MCNearbyServiceBrowser
  private let advertiser: MCNearbyServiceAdvertiser

  private(set) var availablePeers: [MCPeerID] = []

  init(id: String) {
    let id = MCPeerID(displayName: id)
    session = MCSession(peer: id, securityIdentity: nil, encryptionPreference: .required)
    browser = MCNearbyServiceBrowser(peer: id, serviceType: "peered")
    advertiser = MCNearbyServiceAdvertiser(
      peer: browser.myPeerID,
      discoveryInfo: [:],
      serviceType: "peered"
    )
    super.init()
    browser.delegate = self
    start()
  }

  func start() {
    advertiser.startAdvertisingPeer()
    browser.startBrowsingForPeers()
  }

  func stop() {
    browser.stopBrowsingForPeers()
    advertiser.stopAdvertisingPeer()
  }

  func browser(
    _ browser: MCNearbyServiceBrowser,
    foundPeer peerID: MCPeerID,
    withDiscoveryInfo info: [String: String]?
  ) {
    availablePeers.append(peerID)
    browser.invitePeer(peerID, to: session, withContext: nil, timeout: 30)
  }

  func browser(_ browser: MCNearbyServiceBrowser, lostPeer peerID: MCPeerID) {
    availablePeers.removeAll { id in
      id == peerID
    }
  }
}