using System.Buffers.Binary;
using Flyshot.Runtime.Fanuc.Protocol;

namespace Flyshot.Core.Tests;

/// <summary>
/// 验证 FANUC 真机三条通信链路的二进制协议基础与逆向抓包样本一致。
/// </summary>
public sealed class FanucProtocolTests
{
    /// <summary>
    /// 验证 TCP 10012 程序命令封包与抓包中的 StopProg("RVBUSTSM") 完全一致。
    /// </summary>
    [Fact]
    public void CommandProtocol_PacksCapturedStopProgramFrame()
    {
        var frame = FanucCommandProtocol.PackProgramCommand(FanucCommandMessageIds.StopProgram, "RVBUSTSM");

        Assert.Equal(
            Convert.FromHexString("646f7a0000001a0000210300000008525642555354534d7a6f64"),
            frame);
    }

    /// <summary>
    /// 验证 TCP 10012 短响应和程序状态响应可以按抓包字段解析。
    /// </summary>
    [Fact]
    public void CommandProtocol_ParsesCapturedResponses()
    {
        var stopResponse = FanucCommandProtocol.ParseResultResponse(
            Convert.FromHexString("646f7a0000001200002103000000007a6f64"));
        var statusResponse = FanucCommandProtocol.ParseProgramStatusResponse(
            Convert.FromHexString("646f7a000000160000200300000000000000017a6f64"));

        Assert.Equal(FanucCommandMessageIds.StopProgram, stopResponse.MessageId);
        Assert.True(stopResponse.IsSuccess);
        Assert.Equal(FanucCommandMessageIds.GetProgramStatus, statusResponse.MessageId);
        Assert.True(statusResponse.IsSuccess);
        Assert.Equal(1u, statusResponse.ProgramStatus);
    }

    /// <summary>
    /// 验证 TCP 10010 状态帧可以从抓包样本解析出尾部状态槽位。
    /// </summary>
    [Fact]
    public void StateProtocol_ParsesCapturedStateFrame()
    {
        var frame = FanucStateProtocol.ParseFrame(Convert.FromHexString(
            "646f7a0000005a000000004388a23243f1ed7f43e9de6bc265031ec2b33cc3c278e0153f8742f53c3f128dbc929529bc7861d63cb0184c3c1ca1a7000000000000000000000000000000020000000000000000000000017a6f64"));

        Assert.Equal(0u, frame.MessageId);
        Assert.Equal(6, frame.Pose.Count);
        Assert.Equal(9, frame.JointOrExtensionValues.Count);
        Assert.Equal([2u, 0u, 0u, 1u], frame.TailWords);
    }

    /// <summary>
    /// 验证 UDP 60015 的 J519 初始化、结束和命令包字段布局。
    /// </summary>
    [Fact]
    public void J519Protocol_PacksControlAndCommandPackets()
    {
        var command = new FanucJ519Command(
            sequence: 2,
            targetJoints: [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]);

        var packet = FanucJ519Protocol.PackCommandPacket(command);

        Assert.Equal(Convert.FromHexString("0000000000000001"), FanucJ519Protocol.PackInitPacket());
        Assert.Equal(Convert.FromHexString("0000000200000001"), FanucJ519Protocol.PackEndPacket());
        Assert.Equal(FanucJ519Protocol.CommandPacketLength, packet.Length);
        Assert.Equal(1u, BinaryPrimitives.ReadUInt32BigEndian(packet.AsSpan(0x00, 4)));
        Assert.Equal(1u, BinaryPrimitives.ReadUInt32BigEndian(packet.AsSpan(0x04, 4)));
        Assert.Equal(2u, BinaryPrimitives.ReadUInt32BigEndian(packet.AsSpan(0x08, 4)));
        Assert.Equal(2, packet[0x0d]);
        Assert.Equal(1, packet[0x12]);
        Assert.Equal(1.0f, BinaryPrimitives.ReadSingleBigEndian(packet.AsSpan(0x1c, 4)));
        Assert.Equal(6.0f, BinaryPrimitives.ReadSingleBigEndian(packet.AsSpan(0x30, 4)));
        Assert.Equal(0.0f, BinaryPrimitives.ReadSingleBigEndian(packet.AsSpan(0x38, 4)));
    }

    /// <summary>
    /// 验证 UDP 60015 的 132 字节响应包字段可以被解析成状态位和关节反馈。
    /// </summary>
    [Fact]
    public void J519Protocol_ParsesResponsePacket()
    {
        var packet = new byte[FanucJ519Protocol.ResponsePacketLength];
        BinaryPrimitives.WriteUInt32BigEndian(packet.AsSpan(0x00, 4), 0);
        BinaryPrimitives.WriteUInt32BigEndian(packet.AsSpan(0x04, 4), 1);
        BinaryPrimitives.WriteUInt32BigEndian(packet.AsSpan(0x08, 4), 12);
        packet[0x0c] = 15;
        packet[0x0d] = 2;
        BinaryPrimitives.WriteUInt16BigEndian(packet.AsSpan(0x0e, 2), 1);
        BinaryPrimitives.WriteUInt16BigEndian(packet.AsSpan(0x10, 2), 255);
        BinaryPrimitives.WriteUInt16BigEndian(packet.AsSpan(0x12, 2), 10);
        BinaryPrimitives.WriteUInt32BigEndian(packet.AsSpan(0x14, 4), 1234);
        BinaryPrimitives.WriteSingleBigEndian(packet.AsSpan(0x18, 4), 100.5f);
        BinaryPrimitives.WriteSingleBigEndian(packet.AsSpan(0x3c, 4), 1.25f);
        BinaryPrimitives.WriteSingleBigEndian(packet.AsSpan(0x60, 4), 2.5f);

        var response = FanucJ519Protocol.ParseResponse(packet);

        Assert.Equal(12u, response.Sequence);
        Assert.Equal(15, response.Status);
        Assert.True(response.AcceptsCommand);
        Assert.True(response.ReceivedCommand);
        Assert.True(response.SystemReady);
        Assert.True(response.RobotInMotion);
        Assert.Equal(10, response.ReadIoValue);
        Assert.Equal(1234u, response.Timestamp);
        Assert.Equal(100.5, response.Pose[0], precision: 6);
        Assert.Equal(1.25, response.JointDegrees[0], precision: 6);
        Assert.Equal(2.5, response.MotorCurrents[0], precision: 6);
    }
}