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

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

/// <summary>
///     Pins <see cref="DriverArrayWriteSupport"/>'s AbCip row against the REAL write path (#737, review 07 U10), the
///     same way the Modbus, S7 and Galaxy parity tests do: the server advertises an array node writable exactly when
///     <see cref="AbCipDriver.WriteAsync"/> encodes a whole-array value for it (through the production
///     <see cref="AbCipArrayCodec"/>, which the fake runtime's <c>EncodeArray</c> calls), so a driver change that adds
///     or drops an array element type fails here until the table follows.
/// </summary>
/// <remarks>
///     The value written is the CLR array the server hands the driver for the node's <c>DataType</c>: the node manager
///     converts a numeric client array (ScadaBridge's <c>int[]</c>) to the node's element type first, and the codec
///     then converts each element to the controller's type. The fake controller holds exactly
///     <c>width × count</c> bytes, so only the element type and the value can make the write fail.
/// </remarks>
[Trait("Category", "Unit")]
public sealed class AbCipArrayWriteSupportParityTests
{
    private const string Device = "ab://10.0.0.5/1,0";

    private static Array ClrArray(string dataType, int n) => dataType switch
    {
        "Boolean" => Enumerable.Repeat(true, n).ToArray(),
        "SByte" => Enumerable.Repeat((sbyte)1, n).ToArray(),
        "Byte" => Enumerable.Repeat((byte)1, n).ToArray(),
        "Int16" => Enumerable.Repeat((short)1, n).ToArray(),
        "UInt16" => Enumerable.Repeat((ushort)1, n).ToArray(),
        "Int32" => Enumerable.Repeat(1, n).ToArray(),
        "UInt32" => Enumerable.Repeat(1u, n).ToArray(),
        "Int64" => Enumerable.Repeat(1L, n).ToArray(),
        "UInt64" => Enumerable.Repeat(1UL, n).ToArray(),
        "Float" => Enumerable.Repeat(1f, n).ToArray(),
        "Double" => Enumerable.Repeat(1d, n).ToArray(),
        // Non-numeric text: a String node over a numeric element converts only when the text happens to be a
        // number, which is not a write the server can promise — the table keeps it read-only.
        "String" => Enumerable.Repeat("a", n).ToArray(),
        "DateTime" => Enumerable.Repeat(DateTime.UtcNow, n).ToArray(),
        _ => throw new ArgumentOutOfRangeException(nameof(dataType)),
    };

    private static readonly string[] NodeTypes =
        ["Boolean", "SByte", "Byte", "Int16", "UInt16", "Int32", "UInt32", "Int64", "UInt64", "Float", "Double", "String", "DateTime"];

    private static async Task<bool> DriverEncodesAsync(string tagConfig, AbCipDataType elementType, string nodeType, int count)
    {
        // The controller holds exactly what an encodable element array of this length occupies.
        var size = (AbCipArrayCodec.ElementWidth(elementType) ?? 1) * count;
        var factory = new FakeAbCipTagFactory { Customise = p => new FakeAbCipTag(p) { Size = size } };
        using var drv = new AbCipDriver(new AbCipDriverOptions
        {
            Devices = [new AbCipDeviceOptions(Device)],
            RawTags = [new RawTagEntry("Arr", tagConfig, WriteIdempotent: false, DeviceName: Device)],
            Probe = new AbCipProbeOptions { Enabled = false },
        }, "abcip-parity", factory);
        await drv.InitializeAsync("{}", CancellationToken.None);

        var r = await drv.WriteAsync([new WriteRequest("Arr", ClrArray(nodeType, count))], CancellationToken.None);

        return r[0].StatusCode == AbCipStatusMapper.Good
               && factory.Tags.TryGetValue("Arr", out var tag)
               && tag.EncodedArrayCount == count && tag.WriteCount == 1;
    }

    public static TheoryData<AbCipDataType, string> TypeMatrix()
    {
        var data = new TheoryData<AbCipDataType, string>();
        foreach (var t in Enum.GetValues<AbCipDataType>())
            foreach (var n in NodeTypes)
                data.Add(t, n);
        return data;
    }

    /// <summary>Every element type × every node DataType: the table answers exactly what the write path does.</summary>
    [Theory]
    [MemberData(nameof(TypeMatrix))]
    public async Task Table_agrees_with_the_write_path_for_every_element_and_node_type(AbCipDataType dataType, string nodeType)
    {
        var json = $$"""{"tagPath":"Arr","dataType":"{{dataType}}","isArray":true,"arrayLength":3}""";

        var driver = await DriverEncodesAsync(json, dataType, nodeType, 3);

        DriverArrayWriteSupport.Supports(DriverTypeNames.AbCip, nodeType, json).ShouldBe(driver, $"{dataType} on a {nodeType} node");
    }

    /// <summary>
    ///     Shapes beyond the element type, both directions: a safety tag (never writable), an undeclared length (a
    ///     scalar to the factory, whose scalar encoder cannot take an array), a 1-element array, an element-offset path,
    ///     and their positive controls.
    /// </summary>
    [Theory]
    [InlineData("""{"tagPath":"Arr","dataType":"DInt","isArray":true,"arrayLength":3}""", 3)]
    [InlineData("""{"tagPath":"Arr","dataType":"DInt","isArray":true,"arrayLength":1}""", 1)]
    [InlineData("""{"tagPath":"Arr","isArray":true,"arrayLength":3}""", 3)]                          // dataType ⇒ DInt
    [InlineData("""{"tagPath":"Arr","dataType":"DInt","safetyTag":true,"isArray":true,"arrayLength":3}""", 3)]
    [InlineData("""{"tagPath":"Arr","dataType":"DInt","isArray":true}""", 3)]
    [InlineData("""{"tagPath":"Arr","dataType":"DInt","isArray":true,"arrayLength":0}""", 3)]
    [InlineData("""{"tagPath":"Arr","dataType":"DInt","isArray":false,"arrayLength":3}""", 3)]
    public async Task Table_agrees_with_the_write_path_for_each_shape(string tagConfig, int nodeLength)
    {
        var driver = await DriverEncodesAsync(tagConfig, AbCipDataType.DInt, "Int32", nodeLength);

        DriverArrayWriteSupport.Supports(DriverTypeNames.AbCip, "Int32", tagConfig).ShouldBe(driver, tagConfig);
    }

    /// <summary>The ScadaBridge wire shape reaches the codec: a CLR <c>int[]</c> (and <c>List&lt;int&gt;</c>) to an
    /// INT array on an Int16 node the table advertises writable encodes. Positive control for the conversion rule.</summary>
    [Fact]
    public async Task A_ScadaBridge_int_list_to_an_INT_array_encodes()
    {
        const string json = """{"tagPath":"Arr","dataType":"Int","isArray":true,"arrayLength":3}""";
        DriverArrayWriteSupport.Supports(DriverTypeNames.AbCip, "Int16", json).ShouldBeTrue();

        foreach (object value in new object[] { new[] { 1, -2, 300 }, new List<int> { 1, -2, 300 } })
        {
            var factory = new FakeAbCipTagFactory { Customise = p => new FakeAbCipTag(p) { Size = 6 } };
            using var drv = new AbCipDriver(new AbCipDriverOptions
            {
                Devices = [new AbCipDeviceOptions(Device)],
                RawTags = [new RawTagEntry("Arr", json, WriteIdempotent: false, DeviceName: Device)],
                Probe = new AbCipProbeOptions { Enabled = false },
            }, "abcip-parity-sb", factory);
            await drv.InitializeAsync("{}", CancellationToken.None);

            (await drv.WriteAsync([new WriteRequest("Arr", value)], CancellationToken.None))[0].StatusCode
                .ShouldBe(AbCipStatusMapper.Good);
            factory.Tags["Arr"].EncodedArrayBytes.ShouldBe(Convert.FromHexString("0100FEFF2C01"));
        }
    }
}