import Combine

final class StartMiddleware {
    static let shared = StartMiddleware()

    func middleware(state: AppState, action: AppAction) -> AnyPublisher<AppAction, Never> {
        switch action {
        case .accountsAction(.accountsListUpdated(let accounts)):
            if accounts.isEmpty {
                if state.currentFlow == .start {
                    return Just(.startAction(.goTo(.welcomeScreen)))
                        .eraseToAnyPublisher()
                } else {
                    return Empty().eraseToAnyPublisher()
                }
            } else {
                if state.currentFlow == .accounts, state.accountsState.navigation == .addAccount {
                    return Just(.changeFlow(.chats))
                        .eraseToAnyPublisher()
                } else if state.currentFlow == .start {
                    return Just(.changeFlow(.chats))
                        .eraseToAnyPublisher()
                } else {
                    return Empty().eraseToAnyPublisher()
                }
            }

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