using SuiteLink.Client.Protocol;

namespace SuiteLink.Client.Tests.Protocol;

public sealed class SuiteLinkSubscriptionCodecTests
{
    [Fact]
    public void EncodeAdvise_WritesExpectedGoldenVectorWithCallerTagId()
    {
        var bytes = SuiteLinkSubscriptionCodec.EncodeAdvise(0x11223344, "A");
        var frame = SuiteLinkFrameReader.ParseFrame(bytes);
        byte[] expected = [0x0A, 0x00, 0x10, 0x80, 0x44, 0x33, 0x22, 0x11, 0x01, 0x41, 0x00, 0xA5];

        Assert.Equal(expected, bytes);
        Assert.Equal(0x10, bytes[2]);
        Assert.Equal(0x80, bytes[3]);
        Assert.Equal(SuiteLinkSubscriptionCodec.AdviseMessageType, frame.MessageType);
        Assert.Equal(0x11223344u, SuiteLinkEncoding.ReadUInt32LittleEndian(frame.Payload.Span[..4]));
    }

    [Fact]
    public void EncodeAdviseWithoutTagId_UsesExplicitDefaultTagIdOfZero()
    {
        var bytes = SuiteLinkSubscriptionCodec.EncodeAdvise("Pump001.Run");
        var frame = SuiteLinkFrameReader.ParseFrame(bytes);
        Assert.Equal(0u, SuiteLinkEncoding.ReadUInt32LittleEndian(frame.Payload.Span[..4]));
    }

    [Fact]
    public void EncodeUnadvise_WritesExpectedGoldenVector()
    {
        var bytes = SuiteLinkSubscriptionCodec.EncodeUnadvise(0x78563412);
        var frame = SuiteLinkFrameReader.ParseFrame(bytes);
        byte[] expected = [0x07, 0x00, 0x04, 0x80, 0x12, 0x34, 0x56, 0x78, 0xA5];

        Assert.Equal(expected, bytes);
        Assert.Equal(0x04, bytes[2]);
        Assert.Equal(0x80, bytes[3]);
        Assert.Equal(SuiteLinkSubscriptionCodec.UnadviseMessageType, frame.MessageType);
        Assert.Equal(4, frame.Payload.Length);
        Assert.Equal(0x78563412u, SuiteLinkEncoding.ReadUInt32LittleEndian(frame.Payload.Span));
    }

    [Fact]
    public void DecodeAdviseAck_ParsesTagIdFromFixedVector()
    {
        // remaining=0x0008, type=0x0003, payload={tag_id=0x78563412, unknown=0x00}, marker=0xA5
        byte[] frame = [0x08, 0x00, 0x03, 0x00, 0x12, 0x34, 0x56, 0x78, 0x00, 0xA5];

        var ack = SuiteLinkSubscriptionCodec.DecodeAdviseAck(frame);

        Assert.Equal(0x78563412u, ack.TagId);
    }

    [Fact]
    public void DecodeAdviseAckMany_ParsesTwoAckItems()
    {
        // remaining=0x000D, type=0x0003, payload={item1,item2}, marker=0xA5
        byte[] frame =
        [
            0x0D, 0x00, 0x03, 0x00,
            0x12, 0x34, 0x56, 0x78, 0x00,
            0xAA, 0xBB, 0xCC, 0xDD, 0x01,
            0xA5
        ];

        var acks = SuiteLinkSubscriptionCodec.DecodeAdviseAckMany(frame);

        Assert.Equal(2, acks.Count);
        Assert.Equal(0x78563412u, acks[0].TagId);
        Assert.Equal(0xDDCCBBAAu, acks[1].TagId);
    }
}