element-ios/RiotSwiftUI/Modules/Authentication/Registration/AuthenticationRegistrationViewModel.swift

//
// Copyright 2021 New Vector Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

import SwiftUI
import Combine

@available(iOS 14, *)
typealias AuthenticationRegistrationViewModelType = StateStoreViewModel<AuthenticationRegistrationViewState,
                                                                        Never,
                                                                        AuthenticationRegistrationViewAction>


@available(iOS 14, *)
class AuthenticationRegistrationViewModel: AuthenticationRegistrationViewModelType, AuthenticationRegistrationViewModelProtocol {

    // MARK: - Properties

    // MARK: Public

    @MainActor var completion: ((AuthenticationRegistrationViewModelResult) -> Void)?

    // MARK: - Setup

    init(homeserverAddress: String, showRegistrationForm: Bool = true, ssoIdentityProviders: [SSOIdentityProvider]) {
        let bindings = AuthenticationRegistrationBindings()
        let viewState = AuthenticationRegistrationViewState(homeserverAddress: HomeserverAddress.displayable(homeserverAddress),
                                                            showRegistrationForm: showRegistrationForm,
                                                            ssoIdentityProviders: ssoIdentityProviders,
                                                            bindings: bindings)
        
        super.init(initialViewState: viewState)
    }
    
    // MARK: - Public

    override func process(viewAction: AuthenticationRegistrationViewAction) {
        Task {
            await MainActor.run {
                switch viewAction {
                case .selectServer:
                    completion?(.selectServer)
                case .validateUsername:
                    state.hasEditedUsername = true
                    completion?(.validateUsername(state.bindings.username))
                case .enablePasswordValidation:
                    state.hasEditedPassword = true
                case .clearUsernameError:
                    guard state.usernameErrorMessage != nil else { return }
                    state.usernameErrorMessage = nil
                case .next:
                    completion?(.createAccount(username: state.bindings.username, password: state.bindings.password))
                case .continueWithSSO(let id):
                    break
                }
            }
        }
    }
    
    @MainActor func update(homeserverAddress: String, showRegistrationForm: Bool, ssoIdentityProviders: [SSOIdentityProvider]) {
        state.homeserverAddress = HomeserverAddress.displayable(homeserverAddress)
        state.showRegistrationForm = showRegistrationForm
        state.ssoIdentityProviders = ssoIdentityProviders
    }
    
    @MainActor func displayError(_ type: AuthenticationRegistrationErrorType) {
        switch type {
        case .usernameUnavailable(let message):
            state.usernameErrorMessage = message
        case .mxError(let message):
            state.bindings.alertInfo = AlertInfo(id: type,
                                                 title: VectorL10n.error,
                                                 message: message)
        case .invalidHomeserver, .invalidResponse:
            state.bindings.alertInfo = AlertInfo(id: type,
                                                 title: VectorL10n.error,
                                                 message: VectorL10n.authenticationServerSelectionGenericError)
        case .registrationDisabled:
            state.bindings.alertInfo = AlertInfo(id: type,
                                                 title: VectorL10n.error,
                                                 message: VectorL10n.loginErrorRegistrationIsNotSupported)
        case .unknown:
            state.bindings.alertInfo = AlertInfo(id: type)
        }
    }
}