using AVEVA.Historian.Client.Models;
using AVEVA.Historian.Client.Wcf;

namespace AVEVA.Historian.Client.Tests;

public sealed class WcfEventQueryProtocolTests
{
    // Filter block (offset 0x1E into pRequestBuff) captured from a native
    // EventQuery.AddEventFilter("Area", Equal, "RetestFilterArea") StartEventQuery, via
    // instrument-wcf-writemessage.
    private const string CaptureFilterBlockHex =
        "000001000000010000000400000041007200650061000100000000000100000009100052657465737446696c7465724172656100";
    private const int FilterBlockOffset = 0x1E;

    [Fact]
    public void SerializerMatchesInstrumentedNativeEventFilterBlock()
    {
        HistorianEventQueryAttempt attempt = Assert.Single(HistorianEventQueryProtocol.CreateStartEventQueryAttempts(
            new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc),
            5,
            new HistorianEventFilter("Area", HistorianEventComparison.Equal, "RetestFilterArea")));

        byte[] expectedBlock = Convert.FromHexString(CaptureFilterBlockHex);
        byte[] actualBlock = attempt.RequestBuffer[FilterBlockOffset..(FilterBlockOffset + expectedBlock.Length)];

        Assert.Equal("native-filter-version5", attempt.Name);
        Assert.Equal(expectedBlock, actualBlock);
    }

    [Fact]
    public void FilterBlockEncodesComparisonOperatorAsUInt16()
    {
        // Equal = 0, Contains = 12 — the op field is the only byte that differs between them
        // (offset 0x38 in pRequestBuff = 0x1A into the filter block).
        byte[] equal = HistorianEventQueryProtocol.CreateStartEventQueryAttempts(
            new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc),
            5, new HistorianEventFilter("Area", HistorianEventComparison.Equal, "X"))[0].RequestBuffer;
        byte[] contains = HistorianEventQueryProtocol.CreateStartEventQueryAttempts(
            new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc),
            5, new HistorianEventFilter("Area", HistorianEventComparison.Contains, "X"))[0].RequestBuffer;

        Assert.Equal(0x38, FilterBlockOffset + 0x1A);
        Assert.Equal(0, BitConverter.ToUInt16(equal, 0x38));
        Assert.Equal(12, BitConverter.ToUInt16(contains, 0x38));
    }

    [Fact]
    public void NullFilterStillProducesTheEmptyFilterBuffer()
    {
        HistorianEventQueryAttempt withNull = HistorianEventQueryProtocol.CreateStartEventQueryAttempts(
            new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            new DateTime(2026, 1, 1, 0, 1, 0, DateTimeKind.Utc), 3)[0];

        Assert.Equal("native-empty-filter-version5", withNull.Name);
        Assert.Equal(65, withNull.RequestBuffer.Length);
    }

    [Fact]
    public void SerializerMatchesInstrumentedNativeEventRequest()
    {
        HistorianEventQueryAttempt attempt = Assert.Single(HistorianEventQueryProtocol.CreateStartEventQueryAttempts(
            new DateTime(2026, 4, 25, 14, 39, 36, 800, DateTimeKind.Utc).AddTicks(1646),
            new DateTime(2026, 5, 2, 14, 39, 36, 800, DateTimeKind.Utc).AddTicks(1646),
            3));

        byte[] expected = Convert.FromBase64String(
            "BQBuHAVXwdTcAW5c6X9B2twBAwAAAAAAAAAAAAEAAAAAAAAAAAAAAQADAAAAVQBUAEMAAQEAAAEAAAEAAAAAAAA=");

        Assert.Equal(expected, attempt.RequestBuffer);
        Assert.Equal("6b955b02087047a3199a8c74f3eee85c3b49aaa29b05de12eff2dd536f2da0d5", attempt.RequestSha256);
    }

    [Fact]
    public void NativeEmptyFilterAttemptMatchesDecompiledSaveOrder()
    {
        HistorianEventQueryAttempt attempt = Assert.Single(HistorianEventQueryProtocol.CreateStartEventQueryAttempts(
            new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc),
            new DateTime(2026, 1, 1, 0, 1, 0, DateTimeKind.Utc),
            3));

        byte[] actual = attempt.RequestBuffer;

        Assert.Equal("native-empty-filter-version5", attempt.Name);
        Assert.Equal(3, HistorianEventQueryProtocol.QueryRequestTypeEvent);
        Assert.Equal(65, actual.Length);
        Assert.Equal([0x05, 0x00], actual[..2]);
        Assert.Equal(3u, BitConverter.ToUInt32(actual, 18));
        Assert.Equal(0u, BitConverter.ToUInt32(actual, 22));
        Assert.Equal(0, BitConverter.ToUInt16(actual, 26));
        Assert.Equal(1, BitConverter.ToUInt16(actual, 28));
        Assert.Equal([0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00], actual[30..37]);
        Assert.Equal(65_536u, BitConverter.ToUInt32(actual, 37));
        Assert.Equal([0x03, 0x00, 0x00, 0x00, 0x55, 0x00, 0x54, 0x00, 0x43, 0x00], actual[41..51]);
        Assert.Equal([0x01, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00], actual[51..61]);
        Assert.Equal([0x00, 0x00, 0x00, 0x00], actual[^4..]);
    }
}