Skip to content

Instantly share code, notes, and snippets.

@koher

koher/ChatFM.swift

Created June 10, 2025 11:05
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save koher/fa4ae0837532d8d507e4d439ab46225b to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save koher/fa4ae0837532d8d507e4d439ab46225b to your computer and use it in GitHub Desktop.
Download ZIP

Revisions

  1. koher created this gist Jun 10, 2025.
    167 changes: 167 additions & 0 deletions ChatFM.swift
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,167 @@
    import SwiftUI
    import Foundation
    import FoundationModels
    import AudioToolbox

    enum Role: Hashable {
    case user
    case assistant
    }

    struct Message: Identifiable {
    var id: UUID = .init()
    var role: Role
    var text: String
    }

    struct ChatView: View {
    private static let instructions: String = """
    You are a helpful assistant. Answer the user's questions in the same language that the user uses.
    """

    @State private var messages: [Message] = []
    @State private var input: String = ""
    @State private var presentsClearAlert: Bool = false

    @State private var session: LanguageModelSession = .init(instructions: Self.instructions)
    @State private var currentRespondingTask: Task<Void, any Error>?

    var isResponding: Bool { currentRespondingTask != nil }
    var canSendMessage: Bool { !input.isEmpty && !isResponding }

    var body: some View {
    NavigationStack {
    GeometryReader { geometry in
    ScrollViewReader { scrollViewProxy in
    ScrollView {
    VStack {
    ForEach(messages) { message in
    MessageView(message: message)
    .frame(maxWidth: .infinity, alignment: message.role == .user ? .trailing : .leading)
    .padding(message.role == .user ? .leading : .trailing, 40)
    .padding(.horizontal)
    .id(message.id)
    }
    if isResponding {
    ProgressView()
    .frame(maxWidth: .infinity, alignment: .leading)
    .padding(.horizontal)
    }
    Spacer()
    TextField("Ask anything", text: $input)
    .textFieldStyle(.roundedBorder)
    .submitLabel(.send)
    .onSubmit {
    sendMessage(scrollToBottom: {
    withAnimation {
    scrollViewProxy.scrollTo("messages", anchor: .bottom)
    }
    })
    }
    .padding(.horizontal)
    }
    .padding(.vertical)
    .frame(minHeight: geometry.size.height)
    .frame(width: geometry.size.width)
    .id("messages")
    }
    }
    .frame(height: geometry.size.height)
    }
    .toolbar {
    ToolbarItem(placement: .topBarTrailing) {
    Button {
    presentsClearAlert = true
    } label: {
    Image(systemName: "square.and.pencil")
    }
    }
    }
    .alert("Confirmation", isPresented: $presentsClearAlert) {
    Button(role: .cancel) {} label: {
    Text("Cancel")
    }
    Button(role: .destructive) {
    clearChat()
    } label: {
    Text("Clear")
    }
    } message: {
    Text("Are you sure you want to clear the current chat?")
    }
    .navigationTitle(Text("ChatFM"))
    .navigationBarTitleDisplayMode(.inline)
    }
    }

    func sendMessage(scrollToBottom: (() -> Void)?) {
    guard canSendMessage else { return }

    let text = input
    messages.append(.init(role: .user, text: text))
    input = ""
    playSendSound()
    if let scrollToBottom {
    Task {
    scrollToBottom()
    }
    }

    currentRespondingTask = Task {
    defer { currentRespondingTask = nil }

    do {
    let response = try await session.respond(to: text)
    try Task.checkCancellation()
    playReceiveSound()
    let newMessage: Message = .init(role: .assistant, text: response.content)
    messages.append(newMessage)
    if let scrollToBottom {
    Task {
    scrollToBottom()
    }
    }
    } catch is CancellationError {
    // Do nothing
    } catch {
    // TODO: Error handling
    print(error)
    }
    }
    }

    func clearChat() {
    messages = []
    currentRespondingTask?.cancel()
    currentRespondingTask = nil
    session = LanguageModelSession(instructions: Self.instructions)
    }

    func playSendSound() {
    AudioServicesPlaySystemSound(1004)

    }

    func playReceiveSound() {
    AudioServicesPlaySystemSound(1003)
    }
    }

    struct MessageView: View {
    let message: Message

    var body: some View {
    Text(verbatim: message.text)
    .fixedSize(horizontal: false, vertical: true)
    .foregroundStyle(message.role == .user ? .white : .primary)
    .selectionDisabled(false)
    .padding()
    .background {
    let color: Color = switch message.role {
    case .user: .blue
    case .assistant: .init(uiColor: .systemGray6)
    }
    color.cornerRadius(24)
    }
    }
    }