using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Threading;
using ytLive.Helpers;
using ytLive.Models;
using ytLive.Services;
using ytLive.Services.Compositor;

namespace ytLive.ViewModels;

/// <summary>The scoreboard strip: session tallies rendered as a full-width bar, per scene.
///
/// <para>It is a <see cref="SourceType.Scoreboard"/> layer, so a creator gets the same eye toggle,
/// drag and per-scene presence as every other element — "prominent on BRB, dialled back on Live" is
/// geometry, not a second mechanism.</para></summary>
public partial class MainViewModel
{
    private readonly ScoreboardRecorder _scoreboard = new();
    private ScoreboardTiles _scoreboardTiles = ScoreboardTiles.Default;
    private ScoreboardStyle _scoreboardStyle = new();
    private ScoreboardPresenter? _scoreboardPresenter;
    private WriteableBitmap? _scoreboardPreview;
    private Source? _scoreboardPreviewSource;

    internal ScoreboardRecorder ScoreboardRecorder => _scoreboard;

    internal ScoreboardTiles ScoreboardTilesState => _scoreboardTiles;

    /// <summary>Composited strip frame for the output path (cached by the presenter).</summary>
    internal VideoFrame? ScoreboardFrame => _scoreboardPresenter?.Frame;

    internal void StartScoreboardSession()
    {
        _scoreboard.StartSession();
        RefreshScoreboardPreviews();
    }

    internal void EndScoreboardSession()
    {
        _scoreboard.EndSession();
        RefreshScoreboardPreviews();
    }

    /// <summary>One Scoreboard layer in every scene, healed on load — "available to all scenes"
    /// (creator ruling 2026-10-30). Per-scene visibility is the ordinary eye toggle.</summary>
    internal void EnsureScoreboards()
    {
        if (ScoreboardHealer.Ensure(Scenes))
        {
            foreach (var scene in Scenes) _sceneGraph.InvalidateBake(scene);
            RefreshScoreboardPreviews();
            OnPropertyChanged(nameof(LayerCount));
        }
    }

    private void InitScoreboard()
    {
        _scoreboardPresenter = new ScoreboardPresenter(_scoreboard, _scoreboardStyle)
        {
            // placeholder so SetTiles below drives the first render
        };
        _scoreboardPresenter.SetTiles(_scoreboardTiles);
        _scoreboardPresenter.SetStyle(_scoreboardStyle);
        _scoreboard.Changed += RefreshScoreboardPreviews;
    }

    /// <summary>Snapshot of the strip presenters as themed properties, for the properties panel
    /// (unit 7) — kept here so the panel binds one object instead of six primitives.</summary>
    internal ScoreboardStyle ScoreboardStyleState => _scoreboardStyle;

    // ─── Properties panel surface (per layout: one scoreboard look) ────────────

    public string ScoreboardTextColor
    {
        get => _scoreboardStyle.TextColor;
        set { _scoreboardStyle = _scoreboardStyle with { TextColor = value }; PushStyle(); }
    }

    public bool ScoreboardBackgroundEnabled
    {
        get => _scoreboardStyle.BackgroundEnabled;
        set { _scoreboardStyle = _scoreboardStyle with { BackgroundEnabled = value }; PushStyle(); }
    }

    public string ScoreboardBackgroundColor
    {
        get => _scoreboardStyle.BackgroundColor;
        set { _scoreboardStyle = _scoreboardStyle with { BackgroundColor = value }; PushStyle(); }
    }

    public double ScoreboardBackgroundOpacity
    {
        get => _scoreboardStyle.BackgroundOpacity;
        set
        {
            _scoreboardStyle = _scoreboardStyle with { BackgroundOpacity = Math.Clamp(value, 0, 1) };
            PushStyle();
        }
    }

    public double ScoreboardFontSize
    {
        get => _scoreboardStyle.FontSize;
        set
        {
            _scoreboardStyle = _scoreboardStyle with
            {
                FontSize = Math.Clamp(value, ScoreboardLayout.FloorFontSize, ScoreboardLayout.MaxFontSize),
            };
            PushStyle();
        }
    }

    /// <summary>The colours offered for text and plate: the app's one palette.</summary>
    public IReadOnlyList<NamedColor> ScoreboardColorOptions => BorderColorPalette.All;

    public bool ScoreboardShowSubscribers { get => _scoreboardTiles.Subscribers; set => SetTile(t => t.Subscribers = value); }
    public bool ScoreboardShowWatchHours { get => _scoreboardTiles.WatchHours; set => SetTile(t => t.WatchHours = value); }
    public bool ScoreboardShowSuperChats { get => _scoreboardTiles.SuperChats; set => SetTile(t => t.SuperChats = value); }
    public bool ScoreboardShowNewMembers { get => _scoreboardTiles.NewMembers; set => SetTile(t => t.NewMembers = value); }
    public bool ScoreboardShowMilestones { get => _scoreboardTiles.Milestones; set => SetTile(t => t.Milestones = value); }
    public bool ScoreboardShowLastMember { get => _scoreboardTiles.LastMember; set => SetTile(t => t.LastMember = value); }
    public bool ScoreboardShowLastSuperChat { get => _scoreboardTiles.LastSuperChat; set => SetTile(t => t.LastSuperChat = value); }
    public bool ScoreboardShowLastGift { get => _scoreboardTiles.LastGift; set => SetTile(t => t.LastGift = value); }

    private void SetTile(Action<ScoreboardTiles> change)
    {
        change(_scoreboardTiles);
        _scoreboardPresenter?.SetTiles(_scoreboardTiles);
        RefreshScoreboardPreviews();
        OnPropertyChanged(nameof(ScoreboardTilesState));
    }

    private void PushStyle()
    {
        _scoreboardPresenter?.SetStyle(_scoreboardStyle);
        RefreshScoreboardPreviews();
        OnPropertyChanged(nameof(ScoreboardStyleState));
    }

    /// <summary>Publishes the strip to every scoreboard layer's preview element. The pump thread
    /// must never touch a WriteableBitmap, so this runs on the UI thread only.</summary>
    private void RefreshScoreboardPreviews()
    {
        var frame = _scoreboardPresenter?.Frame;
        foreach (var scene in Scenes)
        foreach (var source in scene.Elements.OfType<Source>().Where(s => s.IsScoreboard))
        {
            if (frame is null) { source.VideoImageSource = null; continue; }
            if (_scoreboardPreview is null || _scoreboardPreview.PixelWidth != frame.Width ||
                _scoreboardPreview.PixelHeight != frame.Height)
            {
                _scoreboardPreview = new WriteableBitmap(frame.Width, frame.Height, 96, 96, PixelFormats.Bgra32, null);
            }
            _scoreboardPreview.WritePixels(new System.Windows.Int32Rect(0, 0, frame.Width, frame.Height),
                frame.BgraPixels, frame.Width * 4, 0);
            source.VideoImageSource = _scoreboardPreview;
            _scoreboardPreviewSource = source;
        }
    }
}