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

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

/// <summary>
///     PR ablegacy-13 / #256 — coverage for the 1756-DHRIO DH+ bridge form on
///     <see cref="AbLegacyHostAddress"/>: octal-station validation, slot bounds, port shape,
///     and the PLC-5-only family guard at <c>AbLegacyDriver.InitializeAsync</c>.
/// </summary>
[Trait("Category", "Unit")]
public sealed class AbLegacyDhPlusBridgingTests
{
    [Theory]
    // station 07 octal → 7 decimal
    [InlineData("ab://10.0.0.1/1,3,2,07", 3, 2, 7)]
    // station 77 octal → 63 decimal (top of the DH+ address range)
    [InlineData("ab://10.0.0.1/1,3,2,77", 3, 2, 63)]
    // single-digit station 0..7
    [InlineData("ab://10.0.0.1/1,0,2,0", 0, 2, 0)]
    [InlineData("ab://10.0.0.1/1,16,2,77", 16, 2, 63)]
    // station 10 octal → 8 decimal
    [InlineData("ab://10.0.0.1/1,3,2,10", 3, 2, 8)]
    public void DhPlusBridge_parses_valid_octal_station(string input, int slot, int dhPort, int station)
    {
        var parsed = AbLegacyHostAddress.TryParse(input);
        parsed.ShouldNotBeNull();
        parsed.IsDhPlusBridge.ShouldBeTrue();
        parsed.BackplaneSlot.ShouldBe(slot);
        parsed.DhPlusPort.ShouldBe(dhPort);
        parsed.DhPlusStation.ShouldBe(station);
    }

    [Theory]
    // octal-illegal digits 8 / 9 in the station segment
    [InlineData("ab://10.0.0.1/1,3,2,80")]
    [InlineData("ab://10.0.0.1/1,3,2,90")]
    [InlineData("ab://10.0.0.1/1,3,2,08")]
    [InlineData("ab://10.0.0.1/1,3,2,79")]
    // port-1 not the backplane (must be exactly 1)
    [InlineData("ab://10.0.0.1/0,3,2,77")]
    [InlineData("ab://10.0.0.1/2,3,2,77")]
    // port-3 not the DH+ port (must be exactly 2)
    [InlineData("ab://10.0.0.1/1,3,3,77")]
    [InlineData("ab://10.0.0.1/1,3,1,77")]
    // slot out of range (max 16)
    [InlineData("ab://10.0.0.1/1,17,2,07")]
    [InlineData("ab://10.0.0.1/1,99,2,07")]
    [InlineData("ab://10.0.0.1/1,-1,2,07")]
    // wrong segment count
    [InlineData("ab://10.0.0.1/1,3,2")]
    [InlineData("ab://10.0.0.1/1,3,2,07,extra")]
    public void DhPlusBridge_rejects_invalid_form(string input)
    {
        // The host-address parser still succeeds (the CIP path stays opaque) — only the
        // DH+ accessors are absent. That keeps AB-Legacy compatible with paths shaped
        // similarly to a DHRIO bridge but not actually one (e.g. a future DHRIO-clone
        // module on a non-backplane-1 port).
        var parsed = AbLegacyHostAddress.TryParse(input);
        // For the wrong-segment-count and trailing-extra cases, parsing still produces a
        // generic record with an opaque CipPath and no DH+ surface. For the octal-illegal
        // and slot/port out-of-range cases the same applies — the CIP path is preserved
        // verbatim for libplctag, but the structured DH+ accessors are null because the
        // path didn't pass the strict bridge-form validator.
        parsed.ShouldNotBeNull();
        parsed.IsDhPlusBridge.ShouldBeFalse();
        parsed.BackplaneSlot.ShouldBeNull();
        parsed.DhPlusPort.ShouldBeNull();
        parsed.DhPlusStation.ShouldBeNull();
    }

    [Fact]
    public void DhPlusBridge_diagnostics_surface_all_three_fields()
    {
        var parsed = AbLegacyHostAddress.TryParse("ab://10.0.0.1/1,7,2,42");
        parsed.ShouldNotBeNull();
        parsed.IsDhPlusBridge.ShouldBeTrue();
        parsed.BackplaneSlot.ShouldBe(7);
        parsed.DhPlusPort.ShouldBe(2);
        // 42 octal == 4*8 + 2 == 34 decimal
        parsed.DhPlusStation.ShouldBe(34);
        // CIP path is preserved verbatim — libplctag receives the original octal-station
        // representation, not the decimal-translated one.
        parsed.CipPath.ShouldBe("1,7,2,42");
    }

    [Fact]
    public void NonBridgePath_leaves_dhplus_fields_null()
    {
        // Direct-wired SLC 5/05 — empty path
        var direct = AbLegacyHostAddress.TryParse("ab://10.0.0.1/");
        direct.ShouldNotBeNull();
        direct.IsDhPlusBridge.ShouldBeFalse();
        direct.BackplaneSlot.ShouldBeNull();
        direct.DhPlusPort.ShouldBeNull();
        direct.DhPlusStation.ShouldBeNull();

        // Standard ControlLogix backplane bridge — only two segments, not four
        var twoHop = AbLegacyHostAddress.TryParse("ab://10.0.0.1/1,0");
        twoHop.ShouldNotBeNull();
        twoHop.IsDhPlusBridge.ShouldBeFalse();
        twoHop.BackplaneSlot.ShouldBeNull();
    }

    [Theory]
    [InlineData(AbLegacyPlcFamily.Slc500)]
    [InlineData(AbLegacyPlcFamily.MicroLogix)]
    [InlineData(AbLegacyPlcFamily.LogixPccc)]
    public async Task DhPlusBridge_with_non_plc5_family_throws(AbLegacyPlcFamily nonPlc5)
    {
        var options = new AbLegacyDriverOptions
        {
            Devices = new[]
            {
                new AbLegacyDeviceOptions(
                    HostAddress: "ab://10.0.0.1/1,3,2,07",
                    PlcFamily: nonPlc5),
            },
        };
        var driver = new AbLegacyDriver(options, "drv-test", new FakeAbLegacyTagFactory());
        var ex = await Should.ThrowAsync<InvalidOperationException>(async () =>
            await driver.InitializeAsync("{}", CancellationToken.None));
        ex.Message.ShouldContain("DHRIO");
        ex.Message.ShouldContain("PLC-5-only");
    }

    [Fact]
    public async Task DhPlusBridge_with_plc5_family_initialises_cleanly()
    {
        var options = new AbLegacyDriverOptions
        {
            Devices = new[]
            {
                new AbLegacyDeviceOptions(
                    HostAddress: "ab://10.0.0.1/1,3,2,07",
                    PlcFamily: AbLegacyPlcFamily.Plc5),
            },
            // Probe disabled so InitializeAsync doesn't try to spin a probe loop against a
            // non-existent gateway; the only thing under test is the family validation.
            Probe = new AbLegacyProbeOptions { Enabled = false },
        };
        var driver = new AbLegacyDriver(options, "drv-test", new FakeAbLegacyTagFactory());
        await driver.InitializeAsync("{}", CancellationToken.None);
    }
}