using System.Reflection;
using System.Xml.Linq;
using OpenAC.MosswartMassacre.Views;

namespace OpenAC.MosswartMassacre.Tests.Views;

/// <summary>
/// Every <c>{Binding}</c> in a markup file names a public property of the
/// shape the host expects, so a typo fails here instead of as a panel that
/// refuses to build in the client.
/// </summary>
public sealed class MarkupContractTests
{
    public static TheoryData<string, Type> MarkupFiles => new()
    {
        { MainWindow.MarkupFile, typeof(MainWindow) },
    };

    [Theory]
    [MemberData(nameof(MarkupFiles))]
    public void EveryBindingResolvesWithTheRightShape(string file, Type bindingType)
    {
        XElement root = XDocument.Load(MarkupPath(file)).Root!;
        Dictionary<string, PropertyInfo> properties = bindingType
            .GetProperties(BindingFlags.Public | BindingFlags.Instance)
            .ToDictionary(property => property.Name, StringComparer.Ordinal);

        foreach (XAttribute attribute in root.DescendantsAndSelf().Attributes())
        {
            string value = attribute.Value;
            if (!value.StartsWith('{'))
                continue;
            Assert.Matches("^\\{[^{}]+\\}$", value);
            string name = value[1..^1];
            Assert.True(properties.TryGetValue(name, out PropertyInfo? property),
                $"{file}: {value} on <{attribute.Parent!.Name}> names no public property.");

            string element = attribute.Parent!.Name.LocalName;
            Type expected = (element, attribute.Name.LocalName) switch
            {
                (_, "onclick") => typeof(Action),
                ("field", "onchange" or "onsubmit") => typeof(Action<string>),
                ("menu", "onchange") => typeof(Action<string>),
                ("list", "onchange") => typeof(Action<int>),
                ("slider", "onchange") => typeof(Action<float>),
                (_, "checked" or "selected" or "visible" or "enabled") when element != "list" && element != "menu" => typeof(bool),
                _ => typeof(object),
            };
            if (expected != typeof(object))
                Assert.True(property!.PropertyType == expected,
                    $"{file}: {value} on <{element} {attribute.Name}> is {property.PropertyType.Name}, expected {expected.Name}.");
        }
    }

    [Fact]
    public void The_main_window_builds_its_bindings_without_a_host_ui()
    {
        using var harness = new PluginHarness();
        harness.Login();
        MainWindow window = harness.Feature<MainWindow>();

        Assert.Equal("Total Kills: 0", window.TotalKillsText);
        Assert.Equal("Meta State: Unknown", window.MetaStateText);
        Assert.Equal("WebSocket: [DISCONNECTED]", window.WebSocketText);
        Assert.Equal("Never", window.LastKillValue);
        window.ShowStatistics();
        Assert.True(window.StatisticsSelected);
        Assert.False(window.MainSelected);
    }

    private static string MarkupPath(string file) => Path.Combine(AppContext.BaseDirectory, file);
}