using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Wire;

namespace ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests.Series;

/// <summary>
///     Live-wire coverage (focas-mock) for #257 (<c>cnc_statinfo</c> status flags) and #266 (PMC
///     range coalescing). Skips cleanly when <c>OTOPCUA_FOCAS_SIM_ENDPOINT</c> (default
///     <c>10.100.0.35:8193</c>, the <c>otopcua-focas-fixture</c> container) is unreachable. Read-only: no write path is exercised.
/// </summary>
[Collection(FocasSimCollection.Name)]
public sealed class WireBackendStatusAndPmcTests
{
    private readonly FocasSimFixture _fx;

    /// <summary>Initializes a new instance of the <see cref="WireBackendStatusAndPmcTests"/> class.</summary>
    /// <param name="fx">The FOCAS simulator fixture.</param>
    public WireBackendStatusAndPmcTests(FocasSimFixture fx) => _fx = fx;

    private string DeviceHost => _fx.DeviceUri;

    /// <summary>The mock's <c>cnc_statinfo</c> flags surface through the Status/ subtree and an authored FIXED: tag.</summary>
    [Fact]
    public async Task Status_flags_populate_via_wire_backend()
    {
        if (_fx.SkipReason is not null) Assert.Skip(_fx.SkipReason);
        var ct = TestContext.Current.CancellationToken;

        await _fx.LoadProfileAsync("FWLIB64", ct);
        await _fx.PatchStateAsync(new
        {
            sysinfo = new
            {
                addinfo = 0, max_axis = 8, cnc_type = "M ", mt_type = "M ",
                series = "30i ", version = "A1.0", axes = "1 ",
            },
            axis_names = new[] { "X" },
            statinfo = new { aut = 1, run = 3, motion = 1, mstb = 0, emergency = 0, alarm = 1, edit = 0 },
        }, ct);

        var driver = new FocasDriver(new FocasDriverOptions
        {
            Devices = [new FocasDeviceOptions(DeviceHost)],
            RawTags = FocasRawTags.Entries(
                new FocasTagDefinition("RunFlag", DeviceHost, "FIXED:Status/Run", FocasDataType.Int32, Writable: false)),
            Probe = new FocasProbeOptions { Enabled = false },
            FixedTree = new FocasFixedTreeOptions
            {
                Enabled = true,
                PollInterval = TimeSpan.FromMilliseconds(100),
                ProgramPollInterval = TimeSpan.FromMilliseconds(200),
            },
        }, driverInstanceId: "focas-wire-status", clientFactory: new WireFocasClientFactory());

        await using (driver)
        {
            await driver.InitializeAsync("{}", ct);
            await WaitFor(() => driver.GetDeviceState(DeviceHost) is { LastStatus: not null }, TimeSpan.FromSeconds(5));

            var state = driver.GetDeviceState(DeviceHost);
            state.ShouldNotBeNull();
            state.LastStatus.ShouldNotBeNull();
            state.LastStatus.Run.ShouldBe(3);
            state.LastStatus.Alarm.ShouldBe(1);

            var snaps = await driver.ReadAsync(["RunFlag", $"{DeviceHost}/Status/Alarm", $"{DeviceHost}/Status/RunText"], ct);
            snaps.ShouldAllBe(s => s.StatusCode == FocasStatusMapper.Good);
            snaps[0].Value.ShouldBe(3);
            snaps[1].Value.ShouldBe(1);
            snaps[2].Value.ShouldBe("START");

            // The flags follow the machine.
            await _fx.PatchStateAsync(new { statinfo = new { run = 1, emergency = 1 } }, ct);
            await WaitFor(() => driver.GetDeviceState(DeviceHost) is { LastStatus.Run: 1 }, TimeSpan.FromSeconds(5));
            driver.GetDeviceState(DeviceHost)!.LastStatus!.Emergency.ShouldBe(1);
        }
    }

    /// <summary>
    ///     A poll batch of adjacent PMC bytes is served by ONE range read against the live wire, every tag gets
    ///     its own value, and a tag outside the merge window still reads through the per-tag path. Seeds are
    ///     byte-typed: the mock serves one entry per ADDRESS for every PMC type, which matches the real
    ///     byte-addressed range only for width 1.
    /// </summary>
    [Fact]
    public async Task Adjacent_pmc_bytes_coalesce_into_one_range_read_via_wire_backend()
    {
        if (_fx.SkipReason is not null) Assert.Skip(_fx.SkipReason);
        var ct = TestContext.Current.CancellationToken;

        await _fx.LoadProfileAsync("FWLIB64", ct);
        await _fx.PatchStateAsync(new
        {
            pmc = new { R = new Dictionary<string, object>
            {
                ["200"] = new { type = "byte", value = 17 },
                ["201"] = new { type = "byte", value = 200 },
                ["202"] = new { type = "byte", value = 0b0000_0100 },
                ["203"] = new { type = "byte", value = 9 },
                ["900"] = new { type = "byte", value = 33 },
            }},
        }, ct);

        var counting = new CountingFactory();
        var drv = new FocasDriver(new FocasDriverOptions
        {
            Devices = [new FocasDeviceOptions(DeviceHost)],
            RawTags = FocasRawTags.Entries(
                new FocasTagDefinition("R200", DeviceHost, "R200", FocasDataType.Byte, Writable: false),
                new FocasTagDefinition("R201", DeviceHost, "R201", FocasDataType.Byte, Writable: false),
                new FocasTagDefinition("R202b2", DeviceHost, "R202.2", FocasDataType.Bit, Writable: false),
                new FocasTagDefinition("R203", DeviceHost, "R203", FocasDataType.Byte, Writable: false),
                new FocasTagDefinition("R900", DeviceHost, "R900", FocasDataType.Byte, Writable: false)),
            Probe = new FocasProbeOptions { Enabled = false },
        }, driverInstanceId: "wire-pmc-coalesce", clientFactory: counting);

        await using (drv)
        {
            await drv.InitializeAsync("{}", ct);
            var snaps = await drv.ReadAsync(["R200", "R201", "R202b2", "R203", "R900"], ct);

            snaps.ShouldAllBe(s => s.StatusCode == FocasStatusMapper.Good);
            Convert.ToInt32(snaps[0].Value).ShouldBe(17);
            Convert.ToInt32(snaps[1].Value).ShouldBe(-56);   // 200 as a signed byte
            snaps[2].Value.ShouldBe(true);
            Convert.ToInt32(snaps[3].Value).ShouldBe(9);
            Convert.ToInt32(snaps[4].Value).ShouldBe(33);

            counting.Client.ShouldNotBeNull();
            counting.Client.RangeReads.ShouldBe(1, "R200..R203 merge into one pmc_rdpmcrng");
            counting.Client.SingleReads.ShouldBe(1, "R900 is outside the gap window and reads on its own");
        }
    }

    private sealed class CountingFactory : IFocasClientFactory
    {
        private readonly WireFocasClientFactory _inner = new();
        public CountingClient? Client { get; private set; }
        public void EnsureUsable() => _inner.EnsureUsable();
        public IFocasClient Create() => Client = new CountingClient(_inner.Create());
    }

    private sealed class CountingClient(IFocasClient inner) : IFocasClient
    {
        public int RangeReads { get; private set; }
        public int SingleReads { get; private set; }
        public bool IsConnected => inner.IsConnected;
        public Task ConnectAsync(FocasHostAddress a, TimeSpan t, CancellationToken ct) => inner.ConnectAsync(a, t, ct);
        public Task<(object? value, uint status)> ReadAsync(FocasAddress a, FocasDataType t, CancellationToken ct)
        { SingleReads++; return inner.ReadAsync(a, t, ct); }
        public Task<(IReadOnlyList<long>? slots, uint status)> ReadPmcSlotsAsync(string l, FocasDataType t, int s, int e, CancellationToken ct)
        { RangeReads++; return inner.ReadPmcSlotsAsync(l, t, s, e, ct); }
        public Task<uint> WriteAsync(FocasAddress a, FocasDataType t, object? v, CancellationToken ct) => inner.WriteAsync(a, t, v, ct);
        public Task<bool> ProbeAsync(CancellationToken ct) => inner.ProbeAsync(ct);
        public Task<IReadOnlyList<FocasActiveAlarm>> ReadAlarmsAsync(CancellationToken ct) => inner.ReadAlarmsAsync(ct);
        public Task<FocasSysInfo> GetSysInfoAsync(CancellationToken ct) => inner.GetSysInfoAsync(ct);
        public Task<IReadOnlyList<FocasAxisName>> GetAxisNamesAsync(CancellationToken ct) => inner.GetAxisNamesAsync(ct);
        public Task<IReadOnlyList<FocasSpindleName>> GetSpindleNamesAsync(CancellationToken ct) => inner.GetSpindleNamesAsync(ct);
        public Task<FocasDynamicSnapshot> ReadDynamicAsync(int i, CancellationToken ct) => inner.ReadDynamicAsync(i, ct);
        public Task<FocasProgramInfo> GetProgramInfoAsync(CancellationToken ct) => inner.GetProgramInfoAsync(ct);
        public Task<FocasStatus> GetStatusAsync(CancellationToken ct) => inner.GetStatusAsync(ct);
        public Task<FocasTimer> GetTimerAsync(FocasTimerKind k, CancellationToken ct) => inner.GetTimerAsync(k, ct);
        public Task<IReadOnlyList<FocasServoLoad>> GetServoLoadsAsync(CancellationToken ct) => inner.GetServoLoadsAsync(ct);
        public Task<IReadOnlyList<double?>> GetSpindleLoadsAsync(CancellationToken ct) => inner.GetSpindleLoadsAsync(ct);
        public Task<IReadOnlyList<double?>> GetSpindleMotorSpeedsAsync(CancellationToken ct) => inner.GetSpindleMotorSpeedsAsync(ct);
        public void Dispose() => inner.Dispose();
    }

    private static async Task WaitFor(Func<bool> pred, TimeSpan timeout)
    {
        var deadline = DateTime.UtcNow + timeout;
        while (DateTime.UtcNow < deadline)
        {
            if (pred()) return;
            await Task.Delay(50);
        }
    }
}