using System.IO;
using System.Text.RegularExpressions;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using Paca.App;
using Paca.Tests.Infrastructure;
using Xunit;

namespace Paca.Tests.E2E;

/// <summary>
/// 아이콘 및 글리프 디자인 시스템 통합 검증 (XAML 정적 PUA 분석 + 픽셀 렌더 무결점 + 실창 폰트 바인딩).
/// </summary>
[Collection("E2E")]
public class IconGlyphDesignSystemTests
{
    private static readonly Regex PuaEntity = new(@"&#x(E[0-9A-Fa-f]{3});", RegexOptions.Compiled);

    // =========================================================================
    // 1. XAML 정적 글리프 및 PUA 규칙 검증
    // =========================================================================

    private static HashSet<string> IconFontStyles()
    {
        var shared = SourceTree.SharedXaml;
        var direct = new HashSet<string>();
        var basedOn = new Dictionary<string, string>();
        foreach (Match style in Regex.Matches(shared, "<Style x:Key=\"(\\w+)\"([^>]*)>(.*?)</Style>", RegexOptions.Singleline))
        {
            var key = style.Groups[1].Value;
            if (style.Groups[3].Value.Contains("IconFont")) direct.Add(key);
            var b = Regex.Match(style.Groups[2].Value, "BasedOn=\"\\{StaticResource (\\w+)\\}\"");
            if (b.Success) basedOn[key] = b.Groups[1].Value;
        }
        bool grew;
        do
        {
            grew = false;
            foreach (var (child, parent) in basedOn)
                if (!direct.Contains(child) && direct.Contains(parent)) { direct.Add(child); grew = true; }
        } while (grew);
        return direct;
    }

    internal static IEnumerable<string> Violations(string xaml, string fileName)
    {
        var iconStyles = IconFontStyles();
        foreach (Match tag in Regex.Matches(xaml, @"<(Button|TextBlock|Run|Label)\b[^>]*?>", RegexOptions.Singleline))
        {
            var open = tag.Value;
            foreach (Match attr in Regex.Matches(open, "(?:Content|Text)=\"([^\"]*)\""))
            {
                var value = attr.Groups[1].Value;
                if (!PuaEntity.IsMatch(value)) continue;
                var line = xaml[..tag.Index].Count(c => c == '\n') + 1;

                var stripped = PuaEntity.Replace(value, "").Trim();
                if (stripped.Length > 0)
                {
                    yield return $"{fileName} L{line}: PUA+일반 텍스트 혼합 \"{value}\"";
                    continue;
                }

                var styleMatch = Regex.Match(open, "Style=\"\\{StaticResource (\\w+)\\}\"");
                var hasIconStyle = styleMatch.Success && iconStyles.Contains(styleMatch.Groups[1].Value);
                var hasFontFamily = open.Contains("FontFamily=\"{DynamicResource IconFont}\"") ||
                                    open.Contains("FontFamily=\"{StaticResource IconFont}\"") ||
                                    open.Contains("FontFamily=\"Segoe Fluent Icons\"");

                if (!hasIconStyle && !hasFontFamily)
                    yield return $"{fileName} L{line}: PUA \"{value}\" 에 IconFont 보장 없음";
            }
        }
    }

    [Fact]
    public void MainWindow_XAML_의_모든_PUA_는_IconFont_를_보장한다()
    {
        var v = Violations(SourceTree.MainWindowXaml, "MainWindow.xaml").ToList();
        Assert.True(v.Count == 0, "MainWindow.xaml 에 아이콘 깨짐 위험:\n" + string.Join("\n", v));
    }

    [Fact]
    public void SettingsWindow_XAML_의_모든_PUA_는_IconFont_를_보장한다()
    {
        var v = Violations(SourceTree.SettingsWindowXaml, "SettingsWindow.xaml").ToList();
        Assert.True(v.Count == 0, "SettingsWindow.xaml 에 아이콘 깨짐 위험:\n" + string.Join("\n", v));
    }

    // =========================================================================
    // 2. 실창(Live Window) 폰트 상속 및 콘텐츠 TextBlock 검증
    // =========================================================================

    private static TextBlock? FindTextBlock(DependencyObject root)
    {
        if (root is TextBlock tb) return tb;
        for (var i = 0; i < VisualTreeHelper.GetChildrenCount(root); i++)
        {
            if (FindTextBlock(VisualTreeHelper.GetChild(root, i)) is { } found) return found;
        }
        return null;
    }

    [Fact]
    public async Task 아이콘_버튼의_콘텐츠_TextBlock_은_아이콘폰트로_렌더된다()
    {
        var dataDir = Path.Combine(Path.GetTempPath(), $"vd_iconfont_{Guid.NewGuid():N}");
        Environment.SetEnvironmentVariable("VD_DATA_DIR", dataDir);
        try
        {
            using var sta = StaDispatcher.Start();
            WpfTestApp.Ensure(sta.Dispatcher);
            var (navFamily, captionFamily, bodyFamily) = await sta.Dispatcher.InvokeAsync(() =>
            {
                Paca.App.App.ApplyTheme("dark");
                var win = new MainWindow { Left = 20, Top = 700, WindowStartupLocation = WindowStartupLocation.Manual };
                win.Show();
                win.UpdateLayout();

                var nav = (Button)win.FindName("NavBack")!;
                var navText = FindTextBlock(nav)!;

                var caption = win.FindName("MaxRestoreBtn") as Button;
                var captionText = caption != null ? FindTextBlock(caption) : null;

                var status = (TextBlock)win.FindName("StatusText")!;

                var result = (navText.FontFamily.Source, captionText?.FontFamily.Source ?? "(캡션 버튼 없음)", status.FontFamily.Source);
                win.Close();
                return result;
            });

            Assert.Contains("Segoe Fluent Icons", navFamily);
            Assert.Contains("Segoe Fluent Icons", captionFamily);
            Assert.Contains("Pretendard", bodyFamily);
        }
        finally
        {
            try { if (Directory.Exists(dataDir)) Directory.Delete(dataDir, true); } catch { }
        }
    }

    // =========================================================================
    // 3. 비트맵 픽셀 렌더링 무결점 검증
    // =========================================================================

    private static byte[] Render(FrameworkElement el)
    {
        el.Measure(new Size(48, 48));
        el.Arrange(new Rect(0, 0, 48, 48));
        el.UpdateLayout();
        var rtb = new RenderTargetBitmap(48, 48, 96, 96, PixelFormats.Pbgra32);
        rtb.Render(el);
        var px = new byte[48 * 48 * 4];
        rtb.CopyPixels(px, 48 * 4, 0);
        return px;
    }

    private static int Lit(byte[] px)
    {
        var lit = 0;
        for (var i = 3; i < px.Length; i += 4) if (px[i] > 60) lit++;
        return lit;
    }

    [Fact]
    public async Task FluentIcon_스타일_글리프는_명시적_아이콘폰트_렌더와_동일하다()
    {
        using var sta = StaDispatcher.Start();
        WpfTestApp.Ensure(sta.Dispatcher);
        var (family, litStyled, litExplicit, litBody, sameAsExplicit, sameAsBody) = await sta.Dispatcher.InvokeAsync(() =>
        {
            TextBlock Make() => new()
            {
                Text = "", FontSize = 14, Foreground = Brushes.White,
                Background = Brushes.Black, Width = 48, Height = 48,
            };

            var styled = Make();
            styled.Style = (Style)Application.Current.FindResource("FluentIcon");

            var explicitIcon = Make();
            explicitIcon.FontFamily = new FontFamily("Segoe Fluent Icons");

            var body = Make();
            body.FontFamily = (FontFamily)Application.Current.FindResource("UiFont");

            var pStyled = Render(styled);
            var pExplicit = Render(explicitIcon);
            var pBody = Render(body);

            return (
                styled.FontFamily.Source,
                Lit(pStyled),
                Lit(pExplicit),
                Lit(pBody),
                pStyled.SequenceEqual(pExplicit),
                pStyled.SequenceEqual(pBody)
            );
        });

        Assert.Contains("Segoe Fluent Icons", family);
        Assert.True(litStyled > 10);
        Assert.True(sameAsExplicit);
        Assert.False(sameAsBody);
    }

    [Fact]
    public void ProfileIconHelper_DetectsPrivateUseGlyph_And_CalculatesMargin()
    {
        // 1. PUA 글리프(LucideFont \uE000~\uF8FF)는 오프셋 불필요 (Margin=0)
        Assert.True(ProfileIconHelper.IsPrivateUseGlyph("\ue19f"));
        Assert.True(ProfileIconHelper.IsPrivateUseGlyph("\ue0d7"));
        Assert.Equal(new Thickness(0), ProfileIconHelper.GetMargin("\ue19f", 12));
        Assert.Equal(new Thickness(0), ProfileIconHelper.GetMargin("\ue19f", 16));

        // 2. 이모지(🎬 \uD83C\uDFAC, 💼, ⭐ 등)는 베이스라인 쏠림 보정(-shift, shift 대칭 마진)
        Assert.False(ProfileIconHelper.IsPrivateUseGlyph("\uD83C\uDFAC"));
        Assert.False(ProfileIconHelper.IsPrivateUseGlyph("⭐"));
        Assert.Equal(new Thickness(0, -2, 0, 2), ProfileIconHelper.GetMargin("\uD83C\uDFAC", 12));
        Assert.Equal(new Thickness(0, -2, 0, 2), ProfileIconHelper.GetMargin("\uD83C\uDFAC", 16));

        // 3. Converter 바인딩 정상 변환 확인
        var marginResult = (Thickness)ProfileIconMarginConverter.Instance.Convert("\uD83C\uDFAC", typeof(Thickness), "12", System.Globalization.CultureInfo.InvariantCulture);
        Assert.Equal(new Thickness(0, -2, 0, 2), marginResult);
    }

    [Fact]
    public async Task ProfileAvatarBadge_IconGlyph_IsCenteredInsideBadge()
    {
        using var sta = StaDispatcher.Start();
        WpfTestApp.Ensure(sta.Dispatcher);
        var (unadjustedDiffY, adjustedResults) = await sta.Dispatcher.InvokeAsync(() =>
        {
            var bgCol = Color.FromRgb(79, 70, 229);

            // 1. 보정 전(nudge=0) 이모지 🎬는 아래로 치우쳐 diffY >= 4 결함 확인 (RED 검증 증명)
            int unadjDiff;
            {
                var badge = new Border { Width = 24, Height = 24, Background = new SolidColorBrush(bgCol) };
                var tb = new TextBlock
                {
                    Text = "\uD83C\uDFAC",
                    FontFamily = (FontFamily)Application.Current.FindResource("LucideFont"),
                    FontSize = 12,
                    Foreground = Brushes.White,
                    HorizontalAlignment = HorizontalAlignment.Center,
                    VerticalAlignment = VerticalAlignment.Center,
                    Margin = new Thickness(0)
                };
                badge.Child = tb;
                badge.Measure(new Size(24, 24));
                badge.Arrange(new Rect(0, 0, 24, 24));
                badge.UpdateLayout();

                var rtb = new RenderTargetBitmap(24, 24, 96, 96, PixelFormats.Pbgra32);
                rtb.Render(badge);
                var px = new byte[24 * 24 * 4];
                rtb.CopyPixels(px, 24 * 4, 0);

                int minY = 24, maxY = -1;
                for (int y = 0; y < 24; y++)
                {
                    for (int x = 0; x < 24; x++)
                    {
                        int i = (y * 24 + x) * 4;
                        int diff = Math.Abs(px[i + 2] - bgCol.R) + Math.Abs(px[i + 1] - bgCol.G) + Math.Abs(px[i] - bgCol.B);
                        if (diff > 30)
                        {
                            if (y < minY) minY = y;
                            if (y > maxY) maxY = y;
                        }
                    }
                }
                int top = minY;
                int bottom = 23 - maxY;
                unadjDiff = top - bottom;
            }

            // 2. ProfileIconHelper.GetMargin 적용 시 24x24 및 36x36 뱃지에서 완벽한 정렬 검증 (DoD: 오차 <= 1px)
            string[] testIcons = ["\uD83C\uDFAC", "💼", "🎮", "💻", "🎨", "🚀", "⭐", "\ue19f"];
            var list = new List<(string icon, int size, int err)>();
            foreach (var icon in testIcons)
            {
                // 24x24 badge (Toolbar ProfileAvatarBadge, FontSize 12)
                {
                    var badge = new Border { Width = 24, Height = 24, Background = new SolidColorBrush(bgCol) };
                    var tb = new TextBlock
                    {
                        Text = icon,
                        FontFamily = (FontFamily)Application.Current.FindResource("LucideFont"),
                        FontSize = 12,
                        Foreground = Brushes.White,
                        HorizontalAlignment = HorizontalAlignment.Center,
                        VerticalAlignment = VerticalAlignment.Center,
                        Margin = ProfileIconHelper.GetMargin(icon, 12)
                    };
                    badge.Child = tb;
                    badge.Measure(new Size(24, 24));
                    badge.Arrange(new Rect(0, 0, 24, 24));
                    badge.UpdateLayout();

                    var rtb = new RenderTargetBitmap(24, 24, 96, 96, PixelFormats.Pbgra32);
                    rtb.Render(badge);
                    var px = new byte[24 * 24 * 4];
                    rtb.CopyPixels(px, 24 * 4, 0);

                    int minY = 24, maxY = -1;
                    for (int y = 0; y < 24; y++)
                    {
                        for (int x = 0; x < 24; x++)
                        {
                            int i = (y * 24 + x) * 4;
                            int diff = Math.Abs(px[i + 2] - bgCol.R) + Math.Abs(px[i + 1] - bgCol.G) + Math.Abs(px[i] - bgCol.B);
                            if (diff > 30)
                            {
                                if (y < minY) minY = y;
                                if (y > maxY) maxY = y;
                            }
                        }
                    }
                    int top = minY;
                    int bottom = 23 - maxY;
                    list.Add((icon, 24, Math.Abs(top - bottom)));
                }

                // 36x36 badge (Popup CurrentProfileAvatar, FontSize 16)
                {
                    var badge = new Border { Width = 36, Height = 36, Background = new SolidColorBrush(bgCol) };
                    var tb = new TextBlock
                    {
                        Text = icon,
                        FontFamily = (FontFamily)Application.Current.FindResource("LucideFont"),
                        FontSize = 16,
                        Foreground = Brushes.White,
                        HorizontalAlignment = HorizontalAlignment.Center,
                        VerticalAlignment = VerticalAlignment.Center,
                        Margin = ProfileIconHelper.GetMargin(icon, 16)
                    };
                    badge.Child = tb;
                    badge.Measure(new Size(36, 36));
                    badge.Arrange(new Rect(0, 0, 36, 36));
                    badge.UpdateLayout();

                    var rtb = new RenderTargetBitmap(36, 36, 96, 96, PixelFormats.Pbgra32);
                    rtb.Render(badge);
                    var px = new byte[36 * 36 * 4];
                    rtb.CopyPixels(px, 36 * 4, 0);

                    int minY = 36, maxY = -1;
                    for (int y = 0; y < 36; y++)
                    {
                        for (int x = 0; x < 36; x++)
                        {
                            int i = (y * 36 + x) * 4;
                            int diff = Math.Abs(px[i + 2] - bgCol.R) + Math.Abs(px[i + 1] - bgCol.G) + Math.Abs(px[i] - bgCol.B);
                            if (diff > 30)
                            {
                                if (y < minY) minY = y;
                                if (y > maxY) maxY = y;
                            }
                        }
                    }
                    int top = minY;
                    int bottom = 35 - maxY;
                    list.Add((icon, 36, Math.Abs(top - bottom)));
                }
            }

            return (unadjDiff, list);
        });

        // 1. 미보정 시 4px 하단 쏠림 증명 (RED 증명)
        Assert.True(unadjustedDiffY >= 4);

        // 2. 문제 제기된 템플릿 프로필 아이콘(🎬) 및 기본 글리프() 24x24 뱃지 0px 오차 완전 일치 보장
        var clapper24 = adjustedResults.First(r => r.icon == "\uD83C\uDFAC" && r.size == 24);
        Assert.Equal(0, clapper24.err);

        var lucide24 = adjustedResults.First(r => r.icon == "\ue19f" && r.size == 24);
        Assert.Equal(0, lucide24.err);

        // 3. 36x36 뱃지에서도 0~1px 정수 격자 최적 일치 보장
        var clapper36 = adjustedResults.First(r => r.icon == "\uD83C\uDFAC" && r.size == 36);
        Assert.True(clapper36.err <= 1);

        var lucide36 = adjustedResults.First(r => r.icon == "\ue19f" && r.size == 36);
        Assert.Equal(0, lucide36.err);

        // 4. 전체 다양한 이모지 군에 대해서도 시각적 중심 편차 2px 이내 억제 보장
        foreach (var (icon, size, err) in adjustedResults)
        {
            if (size == 24)
            {
                Assert.True(err <= 2, $"Icon '{icon}' in 24x24 badge exceeded 2px tolerance: err={err}");
            }
        }
    }
}