using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Media.Effects;
using System.Windows.Threading;

namespace VideoDownloader.App.Services;

/// <summary>
/// UC-D11/UC-N02 토스트 알림 — 지정한 호스트 패널(우하단)에 카드를 띄우고
/// 설정된 시간 후 사라지게 한다. 방해 금지(DoNotDisturb)면 표시를 억제하고 알림센터에만 쌓는다.
/// UI 스레드 DispatcherTimer 기반이라 별도 스레드가 없다.
/// </summary>
public sealed class ToastNotifier
{
    private readonly Panel _host;
    private readonly DispatcherTimer _timer;
    private readonly List<string> _history = new();

    /// <summary>토스트 표시 시간. AppConfig.ToastDurationMs 와 연동.</summary>
    public TimeSpan Duration { get; set; } = TimeSpan.FromSeconds(4);

    /// <summary>UC-N15 방해 금지 — true 면 토스트를 띄우지 않고 기록만.</summary>
    public bool DoNotDisturb { get; set; }

    /// <summary>UC-N14 알림 센터용 최근 알림 이력(최신 우선, 상한 100).</summary>
    public IReadOnlyList<string> History => _history.ToList();

    public ToastNotifier(Panel host)
    {
        _host = host;
        _timer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(250) };
        _timer.Tick += (_, _) => Expire();
    }

    /// <summary>토스트 표시. kind 에 따라 아이콘·테두리 색이 달라진다(success/error/info).</summary>
    public void Show(string message, string kind = "info")
    {
        _history.Insert(0, $"[{DateTime.Now:HH:mm}] {message}");
        if (_history.Count > 100) _history.RemoveAt(_history.Count - 100);
        if (DoNotDisturb) return;

        var border = new Border
        {
            Background = (Brush)Application.Current.FindResource("CardBg"),
            BorderBrush = kind switch
            {
                "success" => (Brush)Application.Current.FindResource("SuccessBrush"),
                "error" => (Brush)Application.Current.FindResource("ErrorBrush"),
                _ => (Brush)Application.Current.FindResource("AccentBrush"),
            },
            BorderThickness = new Thickness(1),
            CornerRadius = new CornerRadius(10),
            Padding = new Thickness(14, 10, 14, 10),
            Margin = new Thickness(0, 8, 0, 0),
            MaxWidth = 340,
            Effect = new DropShadowEffect { Opacity = 0.4, BlurRadius = 16, ShadowDepth = 4 },
            Tag = DateTime.UtcNow.Add(Duration),
        };
        var icon = kind switch
        {
            "success" => "\uE73E",
            "error" => "\uE7BA",
            _ => "\uE946",
        };
        var panel = new StackPanel { Orientation = Orientation.Horizontal };
        panel.Children.Add(new TextBlock
        {
            Text = icon,
            FontFamily = (FontFamily)Application.Current.FindResource("IconFont"),
            FontSize = 15,
            Foreground = border.BorderBrush,
            VerticalAlignment = VerticalAlignment.Center,
            Margin = new Thickness(0, 0, 9, 0),
        });
        panel.Children.Add(new TextBlock
        {
            Text = message,
            Foreground = (Brush)Application.Current.FindResource("TextPrimary"),
            FontSize = 12.5,
            TextWrapping = TextWrapping.Wrap,
            VerticalAlignment = VerticalAlignment.Center,
        });
        border.Child = panel;
        border.MouseLeftButtonUp += (_, _) => Collapse(border);
        border.Opacity = 0;
        _host.Children.Add(border);

        border.Loaded += (_, _) =>
        {
            var anim = new DoubleAnimation(0, 1, (System.Windows.Duration)Application.Current.FindResource("Duration.Fast"));
            border.BeginAnimation(UIElement.OpacityProperty, anim);
        };
        if (!_timer.IsEnabled) _timer.Start();
    }

    private void Expire()
    {
        var now = DateTime.UtcNow;
        foreach (var child in _host.Children.OfType<Border>().ToList())
        {
            if (child.Tag is DateTime until && now >= until) Collapse(child);
        }
        if (_host.Children.Count == 0) _timer.Stop();
    }

    private void Collapse(Border border)
    {
        var anim = new DoubleAnimation(1, 0, (System.Windows.Duration)Application.Current.FindResource("Duration.Fast"));
        anim.Completed += (_, _) => _host.Children.Remove(border);
        border.BeginAnimation(UIElement.OpacityProperty, anim);
    }
}