ytLlive/ViewModels/MainViewModel.cs

using System.Collections.ObjectModel;
using System.Windows.Input;
using ytLive.Helpers;
using ytLive.Models;
using ytLive.Services;

namespace ytLive.ViewModels;

public class MainViewModel : ViewModelBase
{
    private readonly YouTubeAuthService _youtubeAuth;
    private readonly YouTubeStreamService _youtubeStream;
    private readonly YouTubeChatService _youtubeChat;

    private Scene? _activeScene;
    private StreamStatus _streamStatus = StreamStatus.Offline;
    private StreamHealth _currentHealth = new();
    private string _streamTitle = string.Empty;
    private string _streamKey = string.Empty;
    private bool _isYouTubeConnected;

    public ObservableCollection<Scene> Scenes { get; } = new();
    public ObservableCollection<ChatMessage> ChatMessages { get; } = new();

    public Scene? ActiveScene
    {
        get => _activeScene;
        set => SetProperty(ref _activeScene, value);
    }

    public StreamStatus StreamStatus
    {
        get => _streamStatus;
        set
        {
            if (SetProperty(ref _streamStatus, value))
            {
                OnPropertyChanged(nameof(IsOffline));
                OnPropertyChanged(nameof(IsLive));
                OnPropertyChanged(nameof(PrimaryButtonText));
            }
        }
    }

    public bool IsOffline => StreamStatus == StreamStatus.Offline;
    public bool IsLive => StreamStatus == StreamStatus.Streaming;

    public StreamHealth CurrentHealth
    {
        get => _currentHealth;
        set => SetProperty(ref _currentHealth, value);
    }

    public string StreamTitle
    {
        get => _streamTitle;
        set => SetProperty(ref _streamTitle, value);
    }

    public string StreamKey
    {
        get => _streamKey;
        set => SetProperty(ref _streamKey, value);
    }

    public bool IsYouTubeConnected
    {
        get => _isYouTubeConnected;
        set
        {
            if (SetProperty(ref _isYouTubeConnected, value))
                OnPropertyChanged(nameof(PrimaryButtonText));
        }
    }

    /// <summary>
    /// Single, context-aware primary button. Follows the user's journey:
    /// not connected → connect, connected+idle → go live, live → stop.
    /// </summary>
    public string PrimaryButtonText => !IsYouTubeConnected
        ? "Connect to YouTube"
        : IsLive
            ? "Stop Stream"
            : "Go Live";

    // Commands
    public ICommand AddSceneCommand { get; }
    public ICommand RemoveSceneCommand { get; }
    public ICommand PrimaryCommand { get; }

    public MainViewModel()
    {
        _youtubeAuth = new YouTubeAuthService("", "");  // TODO: load from config
        _youtubeStream = new YouTubeStreamService(_youtubeAuth);
        _youtubeChat = new YouTubeChatService(_youtubeAuth);

        _youtubeChat.MessageReceived += OnChatMessageReceived;

        AddSceneCommand = new RelayCommand(_ => AddScene());
        RemoveSceneCommand = new RelayCommand(scene => RemoveScene(scene as Scene));
        PrimaryCommand = new RelayCommand(_ => PrimaryAction());

        // Start with a default scene
        AddScene("Scene 1");
    }

    private void AddScene(string? name = null)
    {
        var scene = new Scene { Name = name ?? $"Scene {Scenes.Count + 1}" };
        Scenes.Add(scene);
        ActiveScene = scene;
    }

    private void RemoveScene(Scene? scene)
    {
        if (scene == null) return;
        Scenes.Remove(scene);
        if (ActiveScene == scene)
            ActiveScene = Scenes.FirstOrDefault();
    }

    private void OnChatMessageReceived(ChatMessage message)
    {
        System.Windows.Application.Current.Dispatcher.Invoke(() =>
        {
            ChatMessages.Add(message);
            if (ChatMessages.Count > 500)
                ChatMessages.RemoveAt(0);
        });
    }

    private async void StartStream()
    {
        StreamStatus = StreamStatus.Connecting;

        // TODO: Initialize capture pipeline, encode, and push to RTMP
        // For now, simulate connection
        await Task.Delay(500);
        StreamStatus = StreamStatus.Streaming;
    }

    private void StopStream()
    {
        StreamStatus = StreamStatus.Offline;
    }

    private void ConnectYouTube()
    {
        // TODO: Launch OAuth2 flow in browser
        // For now, this is a stub
        IsYouTubeConnected = false;
    }

    private void PrimaryAction()
    {
        if (!IsYouTubeConnected)
            ConnectYouTube();
        else if (IsLive)
            StopStream();
        else
            StartStream();
    }
}