using System.IO;
using System.Linq;
using System.Xml.Linq;
using Xunit;

namespace ytLive.Tests;

/// <summary>TASK 58 — the creator's style audit (2026-10-21): "in the Live scene, for the
/// layer Stream Alerts, the properties → display — why is the drop-down box not in the same
/// style as the others?" It was never given the theme's <c>YtComboBox</c> style — only a
/// hand-painted Background/Foreground — so WPF fell back to the light system template, and
/// the chat Font drop-down (copied from it) was the same. The sweep found the same smell in
/// every check box and every properties field.
///
/// <para>This test is the guard: every drop-down and check box in the app carries the theme's
/// style, and every field in the properties panel carries the compact theme style and paints
/// no colour of its own — the theme owns the look, so it cannot drift back.</para></summary>
public class PropertiesStyleTests
{
    private static readonly XNamespace Xaml = "http://schemas.microsoft.com/winfx/2006/xaml";

    [Fact]
    public void Every_drop_down_check_box_and_properties_field_carries_the_theme_style()
    {
        // 1. The theme defines the styles the app relies on.
        var theme = XDocument.Load(SourceAssert.RepoPath("Themes", "Controls.xaml"));
        var keys = theme.Descendants()
            .Where(e => e.Name.LocalName == "Style")
            .Select(e => (string?)e.Attribute(Xaml + "Key"))
            .Where(k => k != null)
            .ToHashSet();
        foreach (var required in new[] { "YtComboBox", "YtCheckBox", "YtTextBox", "YtTextBoxCompact" })
            Assert.Contains(required, keys);

        // 2. Every drop-down and check box in the app carries the theme style — an unstyled
        //    one falls back to the light WPF system template.
        foreach (var file in AppXamlFiles())
        {
            var doc = XDocument.Load(file);
            var where = Path.GetFileName(file);

            foreach (var combo in doc.Descendants().Where(e => e.Name.LocalName == "ComboBox"))
                AssertStyled(combo, "YtComboBox",
                    $"{where}: a ComboBox is not styled with YtComboBox — it renders with the light system template");

            // Every check box is a pill switch (creator ruling, 2026-11-01: "all checkboxes as
            // pill switches"), so PropertyPillCheck is the theme style that matters here; YtCheckBox
            // is still accepted where a plain box is deliberate.
            foreach (var check in doc.Descendants().Where(e => e.Name.LocalName == "CheckBox"))
            {
                var style = (string?)check.Attribute("Style") ?? string.Empty;
                Assert.True(
                    style.Contains("PropertyPillCheck", StringComparison.Ordinal)
                    || style.Contains("YtCheckBox", StringComparison.Ordinal),
                    $"{where}: a CheckBox carries no theme style — it renders with the light system template");
            }
        }

        // 3. Every field in the properties panel carries the compact theme style and paints
        //    no colours of its own.
        var left = XDocument.Load(SourceAssert.RepoPath("Controls", "LeftPanel.xaml"));
        var properties = left.Descendants().Single(e => e.Name.LocalName == "StackPanel"
            && (string?)e.Attribute(Xaml + "Name") == "ElementsPanel");

        var fields = properties.Descendants().Where(e => e.Name.LocalName == "TextBox").ToList();
        Assert.NotEmpty(fields);
        foreach (var box in fields)
        {
            AssertStyled(box, "YtTextBoxCompact",
                "a properties field is not styled with YtTextBoxCompact");
            Assert.Null(box.Attribute("Background"));
            Assert.Null(box.Attribute("BorderBrush"));
        }
    }

    /// <summary>The app's XAML: the windows at the repo root plus the carved-up controls.</summary>
    private static string[] AppXamlFiles()
    {
        var root = Path.GetDirectoryName(SourceAssert.RepoPath("ytLive.csproj"))!;
        return Directory.GetFiles(root, "*.xaml", SearchOption.TopDirectoryOnly)
            .Concat(Directory.GetFiles(Path.Combine(root, "Controls"), "*.xaml", SearchOption.TopDirectoryOnly))
            .OrderBy(f => f)
            .ToArray();
    }

    /// <summary>Asserts the element carries the named theme style.</summary>
    private static void AssertStyled(XElement element, string key, string message)
    {
        var style = (string?)element.Attribute("Style");
        Assert.True(style is not null && style.Contains(key, StringComparison.Ordinal), message);
    }
}