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

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

/// <summary>
///     Review 07 U10: an N-file array write (4 elements) round-trips every element on both transports and leaves the
///     words either side untouched. Gated by <see cref="IntegrationWriteGate"/>. Doubles as the real-controller
///     hardware gate: <c>AB_LEGACY_ARRAY_WRITE_BASE</c> (default <c>N7:1</c>) names the first of the SIX consecutive
///     words it uses (base = "before" sentinel, base+1..base+4 = the array, base+5 = "after" sentinel); every one is
///     read first and written back in a <c>finally</c>, so a run restores them byte-exact.
/// </summary>
[Collection(AbLegacyServerCollection.Name)]
[Trait("Category", "Integration")]
[Trait("Simulator", "ab_server-PCCC")]
public sealed class AbLegacyArrayWriteIntegrationTests(AbLegacyServerFixture sim)
{
    /// <summary>The env var naming the first word of the six the test may overwrite (and restores).</summary>
    public const string BaseVar = "AB_LEGACY_ARRAY_WRITE_BASE";

    /// <summary>Seeds the neighbours, writes an <c>int[]</c> to a 4-element Int array, reads it all back, restores.</summary>
    /// <param name="profile">The simulator profile.</param>
    /// <param name="transport">The transport stack the driver runs on.</param>
    [AbLegacyTheory]
    [MemberData(nameof(TransportMatrix.Profiles), MemberType = typeof(TransportMatrix))]
    public async Task N_file_array_write_round_trips_every_element(AbLegacyServerProfile profile, AbLegacyTransport transport)
    {
        if (sim.SkipReasonFor(profile) is { } skip) Assert.Skip(skip);
        IntegrationWriteGate.SkipUnlessWritesAllowed();

        var baseText = Environment.GetEnvironmentVariable(BaseVar) is { Length: > 0 } b ? b : "N7:1";
        var baseAddr = AbLegacyAddress.TryParse(baseText, profile.Family);
        if (baseAddr is not { FileLetter: "N", FileNumber: int file, BitIndex: null, SubElement: null } || baseAddr.IsIndirect)
            throw new InvalidOperationException($"{BaseVar}='{baseText}' must be a plain N-file word such as N7:200.");
        string At(int offset) => $"N{file}:{baseAddr.WordNumber + offset}";

        var deviceUri = $"ab://{sim.Host}:{sim.PortFor(profile)}/{sim.CipPath}";
        var words = Enumerable.Range(0, 6)
            .Select(i => new AbLegacyTagDefinition($"W{i}", deviceUri, At(i), AbLegacyDataType.Int))
            .ToArray();
        await using var drv = new AbLegacyDriver(new AbLegacyDriverOptions
        {
            Devices = [new AbLegacyDeviceOptions(deviceUri, profile.Family)],
            RawTags = AbLegacyRawTags.Entries(
                [.. words, new AbLegacyTagDefinition("Arr", deviceUri, At(1), AbLegacyDataType.Int, ArrayLength: 4)]),
            Timeout = TimeSpan.FromSeconds(5),
            Probe = new AbLegacyProbeOptions { Enabled = false },
            Transport = transport,
            CoalesceReads = false, // read each word on its own, independent of the array path under test
        }, driverInstanceId: $"ablegacy-arraywrite-{profile.Family}-{transport}");
        var ct = TestContext.Current.CancellationToken;
        await drv.InitializeAsync("{}", ct);
        string[] wordRefs = [.. words.Select(w => w.Name)];

        if (profile.Family == AbLegacyPlcFamily.Plc5 && transport == AbLegacyTransport.Native)
        {
            // Native PLC-5 writes are refused before the wire (no capture of the PLC-5 write frames exists).
            (await drv.WriteAsync([new WriteRequest("Arr", new[] { 1, 2, 3, 4 })], ct)).Single()
                .StatusCode.ShouldBe(AbLegacyStatusMapper.BadNotSupported);
            return;
        }

        var original = await drv.ReadAsync(wordRefs, ct);
        original.ShouldAllBe(s => s.StatusCode == AbLegacyStatusMapper.Good, "the six words must exist before anything is written");
        try
        {
            (await drv.WriteAsync([new WriteRequest("W0", (short)111), new WriteRequest("W5", (short)666)], ct))
                .ShouldAllBe(r => r.StatusCode == AbLegacyStatusMapper.Good);

            // ScadaBridge shape: a CLR int[] to an Int16 array node.
            (await drv.WriteAsync([new WriteRequest("Arr", new[] { 10, -20, 30, 32767 })], ct)).Single()
                .StatusCode.ShouldBe(AbLegacyStatusMapper.Good);

            var arr = (await drv.ReadAsync(["Arr"], ct)).Single();
            arr.StatusCode.ShouldBe(AbLegacyStatusMapper.Good);
            arr.Value.ShouldBe(new short[] { 10, -20, 30, 32767 });
            var back = await drv.ReadAsync(wordRefs, ct);
            back.Select(s => Convert.ToInt32(s.Value)).ShouldBe(new[] { 111, 10, -20, 30, 32767, 666 }); // per word, neighbours untouched

            // A length mismatch is refused before the wire and changes nothing.
            (await drv.WriteAsync([new WriteRequest("Arr", new[] { 1, 2, 3 })], ct)).Single()
                .StatusCode.ShouldBe(AbLegacyStatusMapper.BadOutOfRange);
            (await drv.ReadAsync(["Arr"], ct)).Single().Value.ShouldBe(new short[] { 10, -20, 30, 32767 });
        }
        finally
        {
            // Restore all six words exactly as found (CancellationToken.None: restore even if the run was cancelled).
            var restore = words.Select((w, i) => new WriteRequest(w.Name, Convert.ToInt16(original[i].Value))).ToArray();
            (await drv.WriteAsync(restore, CancellationToken.None))
                .ShouldAllBe(r => r.StatusCode == AbLegacyStatusMapper.Good, "restoring the original words must succeed");
        }
    }
}