import SwiftUI

struct AuthView: View {
    
    enum Field {
        case email
        case password
    }
    
    @ObservedObject var viewModel = AuthVM()
    
    @State private var login: String = ""
    @State private var password: String = ""
    @State private var showProgress: Bool = false
    @State private var alert: AlertMessage? = nil
    @FocusState private var focus: Field?
    
    var body: some View {
        ZStack {
            VStack(alignment: .center, spacing: 16) {
                Spacer()
                #if os(iOS)
                TextField("Login", text: $login)
                    .focused($focus, equals: .email)
                    .textContentType(.emailAddress)
                    .keyboardType(.emailAddress)
                #else
                TextField("Login", text: $login)
                    .focused($focus, equals: .email)
                #endif
                SecureField("Password", text: $password)
                    .focused($focus, equals: .password)
                Button("Login") {
                    Task.init {
                        do {
                            self.focus = nil
                            self.showProgress = true
                            try await self.viewModel.login(user: self.login, password: self.password)
                            self.showProgress = false
                        } catch {
                            self.showProgress = false
                            self.alert = .error(error: error)
                        }
                    }
                }
                .alert(item: $alert, content: Alert.init)
                Spacer()
            }
            .buttonStyle(.bordered)
            .controlSize(.large)
            .textFieldStyle(.roundedBorder)
            .padding(20)
            
            if self.showProgress {
                ACProgressView()
            }
        }
    }
}

struct AuthView_Previews: PreviewProvider {
    static var previews: some View {
        Group {
            AuthView()
                .previewDevice("iPhone 8")
            AuthView()
                .preferredColorScheme(.dark)
                .previewDevice("iPhone 8")
        }
    }
}