NewGroupComponent.swift

import AppCore
import ComposableArchitecture
import Foundation
import XXMessengerClient
import XXModels

public struct NewGroupComponent: ReducerProtocol {
  public struct State: Equatable {
    public enum Field: String, Hashable {
      case name
    }

    public init(
      contacts: IdentifiedArrayOf<XXModels.Contact> = [],
      members: IdentifiedArrayOf<XXModels.Contact> = [],
      name: String = "",
      focusedField: Field? = nil
    ) {
      self.contacts = contacts
      self.members = members
      self.name = name
      self.focusedField = focusedField
    }

    public var contacts: IdentifiedArrayOf<XXModels.Contact>
    public var members: IdentifiedArrayOf<XXModels.Contact>
    @BindableState public var name: String
    @BindableState public var focusedField: Field?
  }

  public enum Action: Equatable, BindableAction {
    case start
    case didFetchContacts([XXModels.Contact])
    case didSelectContact(XXModels.Contact)
    case didFinish
    case binding(BindingAction<State>)
  }

  public init() {}

  @Dependency(\.app.messenger) var messenger: Messenger
  @Dependency(\.app.dbManager.getDB) var db: DBManagerGetDB
  @Dependency(\.app.mainQueue) var mainQueue: AnySchedulerOf<DispatchQueue>
  @Dependency(\.app.bgQueue) var bgQueue: AnySchedulerOf<DispatchQueue>

  public var body: some ReducerProtocol<State, Action> {
    BindingReducer()
    Reduce { state, action in
      switch action {
      case .start:
        let myId = try? messenger.e2e.tryGet().getContact().getId()
        return Effect
          .catching { try db() }
          .flatMap { $0.fetchContactsPublisher(.init()) }
          .assertNoFailure()
          .map { $0.filter { $0.id != myId } }
          .map(Action.didFetchContacts)
          .subscribe(on: bgQueue)
          .receive(on: mainQueue)
          .eraseToEffect()

      case .didFetchContacts(let contacts):
        state.contacts = IdentifiedArray(uniqueElements: contacts)
        return .none

      case .didSelectContact(let contact):
        if state.members.contains(contact) {
          state.members.remove(contact)
        } else {
          state.members.append(contact)
        }
        return .none

      case .didFinish:
        return .none

      case .binding(_):
        return .none
      }
    }
  }
}