using System;
using System.Globalization;
using System.Linq;
using System.Windows;
using System.Windows.Media;
using System.Xml.Linq;
using Xunit;

namespace ytLive.Tests;

/// <summary>TASK 61 — the creator (2026-10-21): *"the Y and H boxes under webcam
/// properties should be the same width as the X and W boxes and those widths should be
/// fixed to accommodate the max number of possible digits providing the geometry
/// values."*
///
/// <para>One test: the four geometry fields carry the SAME explicit width (the Y/H
/// fields used to stretch to fill the row, because they were the last child of a
/// DockPanel, while X/W sized themselves to their content), and that width really fits
/// the widest value the panel can show — the largest geometry value (1920 master
/// pixels) with a sign, measured in the app's own font at the field's size.</para></summary>
public class GeometryFieldWidthTests
{
    /// <summary>The widest value a geometry field can show: the master frame is
    /// 1920×1080, so four digits — plus a sign the creator may be typing.</summary>
    private const string WidestValue = "-1920";

    [Fact]
    public void The_webcam_geometry_fields_share_one_fixed_width_that_fits_the_largest_value()
    {
        var doc = XDocument.Load(SourceAssert.RepoPath("Controls", "LeftPanel.xaml"));

        var geometry = doc.Descendants()
            .Where(e => e.Name.LocalName == "TextBlock" && (string?)e.Attribute("Text") == "Geometry")
            .Single(e => ((string?)e.Parent?.Attribute("Visibility") ?? "").Contains("IsWebcamSelected"));

        var rows = geometry.Parent!.Elements().Where(e => e.Name.LocalName == "DockPanel").ToList();
        Assert.Equal(2, rows.Count);

        var fields = rows.SelectMany(r => r.Elements().Where(e => e.Name.LocalName == "TextBox")).ToList();
        Assert.Equal(4, fields.Count);

        // Every field carries the SAME explicit width — a field without one sizes
        // itself to its content, and the last one in the row stretches to fill it.
        var widths = fields.Select(f => (string?)f.Attribute("Width")).ToList();
        Assert.All(widths, w => Assert.False(string.IsNullOrWhiteSpace(w),
            "a geometry field has no fixed width — it sizes itself to its content"));
        Assert.Single(widths.Distinct());

        // And that width fits the widest value the panel can show, in the app's font
        // at the field's size, plus the field's own padding and border.
        var width = double.Parse(widths[0]!, CultureInfo.InvariantCulture);
        var needed = MeasureWidestValue() + 8 /* YtTextBoxCompact padding */ + 2 /* border */;
        Assert.True(width >= needed,
            $"the geometry fields are {width:0}px wide; {needed:0.#}px are needed for '{WidestValue}'");
    }

    /// <summary>The width of the widest possible value, in the app's font at 11px.</summary>
    private static double MeasureWidestValue()
    {
        var typeface = new Typeface(SystemFonts.MessageFontFamily,
            FontStyles.Normal, FontWeights.Normal, FontStretches.Normal);
        return new FormattedText(WidestValue, CultureInfo.CurrentCulture,
            FlowDirection.LeftToRight, typeface, 11, Brushes.Black, pixelsPerDip: 1.0).Width;
    }
}