another.im-ios/old/AppCore/Middlewares/ConversationMiddleware.swift

import Combine

final class ConversationMiddleware {
    static let shared = ConversationMiddleware()

    func middleware(state: AppState, action: AppAction) -> AnyPublisher<AppAction, Never> {
        switch action {
        case .chatsAction(.chatStarted(let chat)):
            return Deferred {
                Future<AppAction, Never> { promise in
                    let roster = state.rostersState.rosters
                        .first { $0.bareJid == chat.account && $0.contactBareJid == chat.participant }
                    promise(.success(.conversationAction(.makeConversationActive(chat: chat, roster: roster))))
                }
            }
            .eraseToAnyPublisher()

        case .conversationAction(.makeConversationActive):
            return Just(AppAction.changeFlow(.conversation)).eraseToAnyPublisher()

        default:
            return Empty().eraseToAnyPublisher()
        }
    }
}