using Shouldly;
using Xunit;

namespace ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests;

/// <summary>
///     Unit tests for <see cref="CalculationDriverProbe"/> — the Calculation pseudo-driver's Test-Connect
///     probe (parse-only, since there is no backend to reach).
/// </summary>
public sealed class CalculationDriverProbeTests
{
    private static readonly CalculationDriverProbe Sut = new();

    [Fact]
    public async Task Empty_config_json_fails()
    {
        var result = await Sut.ProbeAsync("", TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
        result.Ok.ShouldBeFalse();
        result.Message.ShouldNotBeNullOrWhiteSpace();
    }

    [Fact]
    public async Task Malformed_json_fails()
    {
        var result = await Sut.ProbeAsync("not json", TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
        result.Ok.ShouldBeFalse();
        result.Message.ShouldNotBeNullOrWhiteSpace();
    }

    [Fact]
    public async Task A_config_with_no_rawTags_array_is_still_valid()
    {
        var result = await Sut.ProbeAsync("{}", TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
        result.Ok.ShouldBeTrue(result.Message);
    }

    [Fact]
    public async Task A_well_formed_rawTags_config_is_valid()
    {
        const string json = """{"rawTags":[{"rawPath":"calc/e/x","tagConfig":"{}","writeIdempotent":false}]}""";
        var result = await Sut.ProbeAsync(json, TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
        result.Ok.ShouldBeTrue(result.Message);
    }

    /// <summary>
    ///     The probe must not be STRICTER than the real spawn/reinit path: both
    ///     <c>CalculationDriverFactoryExtensions.JsonOptions</c> and <c>CalculationDriver.ReinitJsonOptions</c>
    ///     set <c>AllowTrailingCommas</c> + <c>ReadCommentHandling.Skip</c>. Before this pin the probe's own
    ///     options omitted both, so a config a real deploy would accept could fail Test-Connect as "invalid".
    /// </summary>
    [Fact]
    public async Task Tolerates_trailing_commas_like_the_real_spawn_and_reinit_paths()
    {
        const string json = """{"rawTags":[{"rawPath":"calc/e/x","tagConfig":"{}","writeIdempotent":false},],}""";
        var result = await Sut.ProbeAsync(json, TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
        result.Ok.ShouldBeTrue(result.Message);
    }

    /// <summary>Same parity claim for comments, which the spawn/reinit path also tolerates.</summary>
    [Fact]
    public async Task Tolerates_comments_like_the_real_spawn_and_reinit_paths()
    {
        const string json = """
            {
                // a hand-edited config comment
                "rawTags": []
            }
            """;
        var result = await Sut.ProbeAsync(json, TimeSpan.FromSeconds(1), TestContext.Current.CancellationToken);
        result.Ok.ShouldBeTrue(result.Message);
    }
}