using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Scripting;

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

/// <summary>
///     The Calculation driver's run-guard options: the node-wide <c>Scripting</c> section is the base, and a key
///     authored in the driver's own config overrides only that knob. Before the section was bound, a Calculation
///     driver always ran on the compiled defaults whatever the node configured.
/// </summary>
[Trait("Category", "Unit")]
public sealed class CalculationScriptingOptionsResolutionTests
{
    private static readonly ScriptingOptions Node = new()
    {
        MaxAllocBytesPerRun = 8L * 1024 * 1024,
        QuarantineAfterConsecutiveTimeouts = 7,
        StuckOrphanQuarantineFactor = 4,
    };

    [Fact]
    public void No_driver_keys_and_no_node_options_resolves_null_so_the_guard_uses_its_defaults() =>
        CalculationDriverFactoryExtensions.ResolveScripting(null, null, null, out _).ShouldBeNull();

    [Fact]
    public void No_driver_keys_inherits_every_node_knob()
    {
        var resolved = CalculationDriverFactoryExtensions.ResolveScripting(null, null, Node, out _).ShouldNotBeNull();

        resolved.MaxAllocBytesPerRun.ShouldBe(Node.MaxAllocBytesPerRun);
        resolved.QuarantineAfterConsecutiveTimeouts.ShouldBe(7);
        resolved.StuckOrphanQuarantineFactor.ShouldBe(4);
    }

    [Fact]
    public void A_driver_key_overrides_only_its_own_knob_and_the_node_object_is_not_mutated()
    {
        var resolved = CalculationDriverFactoryExtensions.ResolveScripting(null, 2, Node, out var adjustments).ShouldNotBeNull();

        resolved.QuarantineAfterConsecutiveTimeouts.ShouldBe(2);
        resolved.MaxAllocBytesPerRun.ShouldBe(Node.MaxAllocBytesPerRun, "the unauthored key keeps the node value");
        resolved.StuckOrphanQuarantineFactor.ShouldBe(4, "the stuck factor has no driver key; it is node-wide");
        resolved.ShouldNotBeSameAs(Node);
        Node.QuarantineAfterConsecutiveTimeouts.ShouldBe(7);
        adjustments.ShouldBeEmpty();
    }

    /// <summary>Review m-2: an out-of-range value authored in the driver's own config is clamped AND reported, so
    /// the factory can log it rather than the guard changing it silently.</summary>
    [Fact]
    public void An_out_of_range_driver_key_is_clamped_and_reported()
    {
        var resolved = CalculationDriverFactoryExtensions.ResolveScripting(1024L, 0, Node, out var adjustments).ShouldNotBeNull();

        resolved.MaxAllocBytesPerRun.ShouldBe(ScriptingOptions.MinMaxAllocBytesPerRun);
        resolved.QuarantineAfterConsecutiveTimeouts.ShouldBe(1);
        adjustments.Count.ShouldBe(2);
    }

    [Fact]
    public void A_driver_key_with_no_node_options_layers_on_the_compiled_defaults()
    {
        var resolved = CalculationDriverFactoryExtensions.ResolveScripting(0L, null, null, out _).ShouldNotBeNull();

        resolved.MaxAllocBytesPerRun.ShouldBe(0);
        resolved.QuarantineAfterConsecutiveTimeouts.ShouldBe(ScriptingOptions.DefaultQuarantineAfterConsecutiveTimeouts);
    }
}