using ytLive.Helpers;
using ytLive.Models;
using ytLive.Services;

namespace ytLive.ViewModels;

public partial class MainViewModel
{
    private bool _isConnected;
    private string _accountAvatarUrl = string.Empty;
    private string _accountDisplayName = string.Empty;

    public bool IsConnected
    {
        get => _isConnected;
        set
        {
            if (SetProperty(ref _isConnected, value))
            {
                // ON-AIR requires a sign-in; dropping the session turns the pill
                // off so the state can never offer a stream without an account.
                if (!value) OnAirPillOn = false;
                OnPropertyChanged(nameof(PrimaryStartButtonLabel));
                OnPropertyChanged(nameof(ShowPrimaryStartButton));
                OnPropertyChanged(nameof(AccountStatusLightToolTip));
            }
        }
    }

    /// <summary>The connected YouTube account's avatar + name — shown in the top
    /// bar so the creator always sees WHICH account is about to go live.</summary>
    public string AccountAvatarUrl
    {
        get => _accountAvatarUrl;
        private set => SetProperty(ref _accountAvatarUrl, value);
    }

    public string AccountDisplayName
    {
        get => _accountDisplayName;
        private set => SetProperty(ref _accountDisplayName, value);
    }

    /// <summary>Tooltip for the account status light explaining the color.</summary>
    public string AccountStatusLightToolTip =>
        IsLive ? "Live on YouTube — the top bar is red to show the stream is on the air."
        : IsConnected ? "You're signed in to YouTube. The light is green; ON-AIR is available."
        : "Signed out — the light is red. You can still record locally; arming ON-AIR arms intent, and Start turns that intent into a sign-in.";

    // Restores the DPAPI-saved OAuth session so sign-in survives restarts.
    // Best-effort: refresh a near-expiry access token; a session that can no
    // longer refresh is discarded and the user signs in again.
    private async Task LoadSavedSessionAsync()
    {
        try
        {
            var saved = TokenStore.Load();
            if (saved == null) return;

            _youtubeAuth.SetSession(saved);
            if (saved.TokenExpiry <= DateTime.UtcNow.AddMinutes(5))
            {
                var refreshed = await Task.Run(() => _youtubeAuth.RefreshToken());
                if (!refreshed)
                {
                    TokenStore.Clear();
                    AppLog.Write("Saved session could not be refreshed; signed out");
                    _notifications.Info("Signed out of YouTube",
                        "The saved session expired — sign in again when you next go live.");
                    return;
                }
            }

            IsConnected = true;
            SyncConnectedAccount();
        }
        catch (Exception ex)
        {
            AppLog.Write($"LoadSavedSessionAsync failed: {ex}");
        }
    }

    private void SyncConnectedAccount()
    {
        var channel = _youtubeAuth.CurrentChannel;
        AccountAvatarUrl = channel?.ProfileImageUrl ?? string.Empty;
        AccountDisplayName = channel?.DisplayName ?? string.Empty;
    }

    // Runs the OAuth flow (browser + loopback callback) on a background thread.
    // The resulting channel is returned to the caller and persisted via the
    // auth service's sessionChanged hook.
    private async Task<YouTubeChannel?> SignInAsync()
    {
        try
        {
            var channel = await Task.Run(() => _youtubeAuth.AuthenticateAsync());
            if (channel == null)
            {
                _notifications.Warning("Sign-in was unsuccessful", "Please try again.");
                return null;
            }

            IsConnected = true;
            SyncConnectedAccount();
            return channel;
        }
        catch (Exception ex)
        {
            _notifications.Error("Sign-in failed", ex.Message);
            return null;
        }
    }

    /// <summary>Signs out of YouTube (the delete-the-YouTube-slot action in the dialog).</summary>
    private async Task SignOutYouTubeAsync()
    {
        _youtubeAuth.ClearSession();
        TokenStore.Clear();
        IsConnected = false;
        SyncConnectedAccount();
        NotifySocialsChanged();
        AppLog.Write("Socials: signed out of YouTube");
        await Task.CompletedTask;
    }

    private async Task ChangeAccountAsync()
    {
        await SignOutYouTubeAsync();
        await SignInAsync();
    }
}