using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.AdminUI.ScriptAnalysis;

namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests.ScriptAnalysis;

/// <summary>
///     R04:P1 / S2 — the Monaco editor no longer ships its text over the circuit per keystroke; the page reads it on
///     demand at blur / Save. That single read is one hub message, so the Blazor hub's receive limit is raised from
///     the 32 KB default to 1 MB, and the JS refuses (rather than sends) a value that would not fit.
/// </summary>
public sealed class MonacoSyncTests
{
    private static HubOptions ComponentHubOptions(IServiceProvider sp)
    {
        // ComponentHub is internal to Microsoft.AspNetCore.Components.Server; resolve its options by type name.
        var hubType = Type.GetType("Microsoft.AspNetCore.Components.Server.ComponentHub, Microsoft.AspNetCore.Components.Server", throwOnError: true)!;
        var optionsType = typeof(IOptions<>).MakeGenericType(typeof(HubOptions<>).MakeGenericType(hubType));
        var options = sp.GetRequiredService(optionsType);
        return (HubOptions)optionsType.GetProperty("Value")!.GetValue(options)!;
    }

    [Fact]
    public void The_blazor_hub_accepts_a_1_MB_message()
    {
        var services = new ServiceCollection();
        services.AddLogging();
        services.AddAdminUI();
        using var sp = services.BuildServiceProvider();

        ComponentHubOptions(sp).MaximumReceiveMessageSize.ShouldBe(1024 * 1024);
        ScriptEditorLimits.HubMaximumReceiveMessageSize.ShouldBe(1024 * 1024);
    }

    [Fact]
    public void Without_AddAdminUI_the_default_limit_is_the_32_KB_that_truncated_large_scripts()
    {
        // Positive control for the test above: the 1 MB comes from AddAdminUI, not from a framework default.
        var services = new ServiceCollection();
        services.AddLogging();
        services.AddRazorComponents().AddInteractiveServerComponents();
        using var sp = services.BuildServiceProvider();

        (ComponentHubOptions(sp).MaximumReceiveMessageSize ?? 32 * 1024).ShouldBe(32 * 1024);
    }

    [Fact]
    public void The_editor_sync_budget_leaves_headroom_inside_the_hub_limit_and_fits_a_100_KB_script()
    {
        ScriptEditorLimits.MaxEditorSyncBytes.ShouldBeLessThan((int)ScriptEditorLimits.HubMaximumReceiveMessageSize);
        ScriptEditorLimits.MaxEditorSyncBytes.ShouldBeGreaterThan(4 * 100 * 1024);   // 100 KB even after escaping twice
    }
}