using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Driver.AbLegacy;

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

/// <summary>
///     Gitea #534 — the authored EtherNet/IP port must reach libplctag's <c>gateway</c> attribute.
/// </summary>
/// <remarks>
///     <para>
///         <see cref="AbLegacyTagCreateParams.Port"/> was carried on the record and consumed by nobody:
///         the runtime set <c>Tag.Gateway = p.Gateway</c>, the bare host. libplctag does not fail on a
///         portless gateway — it substitutes 44818. So the authored port was not ignored in the harmless
///         sense; the connection was silently *redirected* to whatever answers on the default port. On the
///         test rig that was a different simulator running a different PLC family, which is why the
///         AbLegacy integration suite failed in a way that looked like a missing fixture. On a plant
///         network it is another PLC, and the driver would read someone else's tags and report them Good.
///     </para>
///     <para>
///         The real guard is the integration suite, which now addresses each PCCC family on its own
///         non-default port (44819/44820/44821) and therefore cannot pass unless the port is honoured.
///         These unit tests pin the composition itself so the rule survives on a machine with no fixtures.
///     </para>
/// </remarks>
public sealed class AbLegacyGatewayCompositionTests
{
    private static AbLegacyTagCreateParams Params(string host, int port) =>
        new(Gateway: host, Port: port, CipPath: "1,0", LibplctagPlcAttribute: "slc500",
            TagName: "N7:0", Timeout: TimeSpan.FromSeconds(5));

    [Fact]
    public void The_authored_port_is_appended_to_the_gateway()
    {
        Params("10.100.0.35", 44819).LibplctagGateway.ShouldBe("10.100.0.35:44819");
    }

    [Fact]
    public void The_default_port_is_still_written_explicitly()
    {
        // Not an optimisation opportunity: emitting the port unconditionally is what makes the value
        // independent of libplctag's own default, so a change to that default cannot move our traffic.
        Params("plc1.plant.local", 44818).LibplctagGateway.ShouldBe("plc1.plant.local:44818");
    }

    [Theory]
    [InlineData(0)]
    [InlineData(-1)]
    public void A_missing_port_falls_back_to_the_bare_host(int port)
    {
        // An unset port must not produce "host:0", which libplctag would take literally.
        Params("10.100.0.35", port).LibplctagGateway.ShouldBe("10.100.0.35");
    }
}