using System.IO;
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Interop;
using Microsoft.Web.WebView2.Core;
using VideoDownloader.App.Browser.Features;
using VideoDownloader.Core.Config;
using Wv2 = Microsoft.Web.WebView2.Wpf;

namespace VideoDownloader.App.Browser;

/// <summary>
/// T2-10 미디어 재생목록 플레이어: Direct(MP4)/HLS(hls.js)/DASH(dash.js) 를
/// 생성된 HTML 플레이어로 재생. 곡 종료 시 다음 트랙 자동 재생(연속 재생).
/// </summary>
public sealed class PlayerWindow : Window
{
    private readonly CoreWebView2Environment _env;
    private readonly AppConfig _config;
    private readonly Wv2.WebView2 _web = new() { DefaultBackgroundColor = System.Drawing.Color.Black };
    private MediaPlaylist _playlist;
    private readonly TextBlock _title;

    public PlayerWindow(CoreWebView2Environment env, AppConfig config, MediaPlaylist playlist)
    {
        _env = env;
        _config = config;
        _playlist = playlist;

        Title = "재생목록 — Video Downloader";
        Width = 900; Height = 620;
        WindowStartupLocation = WindowStartupLocation.CenterOwner;

        var bar = new Border { Background = System.Windows.Media.Brushes.Black, Padding = new Thickness(8, 6, 8, 6) };
        var dock = new DockPanel();
        var prev = MkBtn("⏮ 이전", () => { _playlist.Previous(); PlayCurrent(); });
        var next = MkBtn("⏭ 다음", () => { _playlist.Next(); PlayCurrent(); });
        var close = MkBtn("✕ 닫기", () => Close());
        _title = new TextBlock { Foreground = System.Windows.Media.Brushes.LightGray, FontSize = 12, VerticalAlignment = VerticalAlignment.Center, TextTrimming = TextTrimming.CharacterEllipsis, Margin = new Thickness(8, 0, 8, 0) };
        DockPanel.SetDock(close, Dock.Right);
        DockPanel.SetDock(next, Dock.Right);
        DockPanel.SetDock(prev, Dock.Left);
        dock.Children.Add(close);
        dock.Children.Add(next);
        dock.Children.Add(prev);
        dock.Children.Add(_title);
        bar.Child = dock;

        var grid = new Grid { RowDefinitions = { new RowDefinition { Height = GridLength.Auto }, new RowDefinition { Height = new GridLength(1, GridUnitType.Star) } } };
        Grid.SetRow(bar, 0); Grid.SetRow(_web, 1);
        grid.Children.Add(bar);
        grid.Children.Add(_web);
        Content = grid;

        Loaded += async (_, _) =>
        {
            try
            {
                var options = _env.CreateCoreWebView2ControllerOptions();
                if (_config.PrivateMode) options.IsInPrivateModeEnabled = true;
                await _web.EnsureCoreWebView2Async(_env, options);
                var cv = _web.CoreWebView2!;
                cv.WebMessageReceived += (_, we) =>
                {
                    try
                    {
                        var msg = we.WebMessageAsJson;
                        if (string.IsNullOrEmpty(msg)) return;
                        using var doc = System.Text.Json.JsonDocument.Parse(msg);
                        if (doc.RootElement.TryGetProperty("vdEnded", out var e) && e.GetBoolean())
                        {
                            Dispatcher.BeginInvoke(new Action(() =>
                            {
                                var cur = _playlist.Current;
                                if (cur != null) _playlist.MarkPlayed(cur);
                                _playlist.Next();
                                PlayCurrent();
                            }));
                        }
                    }
                    catch { }
                };
                PlayCurrent();
            }
            catch { }
        };

    }

    protected override void OnSourceInitialized(EventArgs e)
    {
        base.OnSourceInitialized(e);
        try
        {
            var hwnd = new WindowInteropHelper(this).Handle;
            int dark = 1;
            DwmSetWindowAttribute(hwnd, 20, ref dark, sizeof(int));
        }
        catch { }
    }

    [System.Runtime.InteropServices.DllImport("dwmapi.dll")]
    private static extern int DwmSetWindowAttribute(IntPtr hwnd, int attribute, ref int pvAttribute, int cbAttribute);

    private Button MkBtn(string text, Action onClick)
    {
        var b = new Button
        {
            Content = text,
            Padding = new Thickness(10, 3, 10, 3),
            Margin = new Thickness(4, 0, 4, 0),
            Background = System.Windows.Media.Brushes.Transparent,
            Foreground = System.Windows.Media.Brushes.White,
            BorderBrush = System.Windows.Media.Brushes.Gray
        };
        b.Click += (_, _) => onClick();
        return b;
    }

    public void PlayCurrent()
    {
        var track = _playlist.Current;
        if (track == null) { _title.Text = "재생목록이 비었습니다"; return; }
        _title.Text = $"{_playlist.CurrentIndex + 1}/{_playlist.Tracks.Count} · {track.Title} [{track.Kind}]";
        try { _web.CoreWebView2?.NavigateToString(BuildPlayerHtml(track)); }
        catch { }
    }

    /// <summary>트랙 재생 HTML — HLS 는 hls.js, DASH 는 dash.js 번들 인라인.</summary>
    public static string BuildPlayerHtml(MediaTrack track)
    {
        var url = track.Url.Replace("&", "&amp;").Replace("\"", "&quot;").Replace("<", "&lt;");
        var isHls = track.Kind == "Hls" || track.Url.Contains(".m3u8", StringComparison.OrdinalIgnoreCase);
        var isDash = track.Kind == "Dash" || track.Url.Contains(".mpd", StringComparison.OrdinalIgnoreCase);
        var hls = isHls ? ReadResource("VideoDownloader.App.Assets.hls.min.js") : "";
        var dash = isDash ? ReadResource("VideoDownloader.App.Assets.dash.all.min.js") : "";

        var loader = "";
        if (isHls) loader = "if (Hls.isSupported()) { var h = new Hls(); h.loadSource(SRC); h.attachMedia(v); } else v.src = SRC;";
        else if (isDash) loader = "var p = dashjs.MediaPlayer().create(); p.initialize(v, SRC, true);";
        else loader = "v.src = SRC;";

        var html = "<!DOCTYPE html><html><head><meta charset='utf-8'><style>" +
            "body{background:#000;margin:0;overflow:hidden}video{width:100vw;height:100vh}" +
            "</style></head><body><video id='v' controls autoplay playsinline></video>" +
            "<script>var SRC=" + System.Text.Json.JsonSerializer.Serialize(track.Url) + ";" +
            (hls.Length > 0 ? "<script>" + hls + "</script>" : "") +
            (dash.Length > 0 ? "<script>" + dash + "</script>" : "") +
            "<script>(function(){var v=document.getElementById('v');" + loader +
            "v.addEventListener('ended',function(){try{window.chrome.webview.postMessage({vdEnded:true});}catch(e){}});" +
            "v.addEventListener('error',function(){try{window.chrome.webview.postMessage({vdEnded:true});}catch(e){}});})();" +
            "</script></body></html>";
        return html;
    }

    private static string ReadResource(string name)
    {
        var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream(name);
        return stream == null ? "" : new StreamReader(stream).ReadToEnd();
    }
}