using System.Diagnostics;
using InnovEnergy.Lib.Protocols.Modbus.Connections;
using InnovEnergy.Lib.Protocols.Modbus.Conversions;
using InnovEnergy.Lib.Protocols.Modbus.Protocol.Frames.Commands;
using InnovEnergy.Lib.Protocols.Modbus.Protocol.Frames.Replies;
using InnovEnergy.Lib.Protocols.Modbus.Tcp;
using static InnovEnergy.Lib.Protocols.Modbus.Clients.Endianness;

namespace InnovEnergy.Lib.Protocols.Modbus.Clients;

using UInt16s = IReadOnlyList<UInt16>;
using Coils   = IReadOnlyList<Boolean>;

public class ModbusTcpClient : ModbusClient
{
    public const UInt16 DefaultPort = 502;
    private UInt16 _Id;
    
    [DebuggerStepThrough]
    private UInt16 NextId() => unchecked(++_Id);


    public ModbusTcpClient(ModbusConnection connection, Byte slaveId, Endianness endianness = LittleEndian32BitIntegers | LittleEndian32Floats) : base(connection, slaveId, endianness)
    {
    }

    
    public override IReadOnlyList<Boolean> ReadDiscreteInputs(UInt16 readAddress, UInt16 nValues)
    {
        var id  = NextId(); // TODO: check response id
        
        var cmd = new ReadDiscreteInputsCommandFrame(SlaveId, readAddress, nValues);
        var hdr = new MbapHeader(id, cmd.Data.Count);  
        var frm = new ModbusTcpFrame(hdr, cmd);         

        Connection.Transmit(frm.Data);

        var hData = Connection.Receive(MbapHeader.Size).ToArray();  // TODO: optimize .ToArray() ?
        var rxHdr = new MbapHeader(hData);

        var fData = Connection.Receive(rxHdr.FrameLength).ToArray(); // TODO: optimize .ToArray() ?
        var rxFrm = ReadDiscreteInputResponseFrame.Parse(fData);

        return cmd.VerifyResponse(rxFrm).Inputs;
    }

    public override ModbusRegisters ReadInputRegisters(UInt16 readAddress, UInt16 nValues)
    {
        var id  = NextId(); // TODO: check response id
        
        var cmd = new ReadInputRegistersCommandFrame(SlaveId, readAddress, nValues);
        var hdr = new MbapHeader(id, cmd.Data.Count);
        var frm = new ModbusTcpFrame(hdr, cmd);

        Connection.Transmit(frm.Data);

        var hData = Connection.Receive(MbapHeader.Size).ToArray();
        var rxHdr = new MbapHeader(hData);

        var fData = Connection.Receive(rxHdr.FrameLength).ToArray();
        var rxFrm = ReadInputRegistersResponseFrame.Parse(fData);

        var verified = cmd.VerifyResponse(rxFrm);

        return new ModbusRegisters(readAddress, verified.RegistersRead.ToArray());
    }


    public override ModbusRegisters ReadHoldingRegisters(UInt16 readAddress, UInt16 nValues)
    {
        var id  = NextId(); // TODO: check response id
        
        var cmd = new ReadHoldingRegistersCommandFrame(SlaveId, readAddress, nValues);
        var hdr = new MbapHeader(id, cmd.Data.Count);
        var frm = new ModbusTcpFrame(hdr, cmd);

        Connection.Transmit(frm.Data);

        var hData = Connection.Receive(MbapHeader.Size).ToArray();
        var rxHdr = new MbapHeader(hData);

        var fData = Connection.Receive(rxHdr.FrameLength).ToArray();
        var rxFrm = ReadHoldingRegistersResponseFrame.Parse(fData);

        var verified = cmd.VerifyResponse(rxFrm);

        return new ModbusRegisters(readAddress, verified.RegistersRead.ToArray());
    }

    public override UInt16 WriteMultipleCoils(UInt16 writeAddress, Coils coils)
    {
        var id  = NextId(); // TODO: check response id
                
        var cmd = new WriteCoilsCommandFrame(SlaveId, writeAddress, coils);
        var hdr = new MbapHeader(id, cmd.Data.Count);
        var frm = new ModbusTcpFrame(hdr, cmd);

        Connection.Transmit(frm.Data);

        var hData = Connection.Receive(MbapHeader.Size).ToArray();
        var rxHdr = new MbapHeader(hData);

        var fData = Connection.Receive(rxHdr.FrameLength).ToArray();
        var rxFrm = WriteCoilsResponseFrame.Parse(fData);

        return cmd.VerifyResponse(rxFrm).NbWritten;
    }
    
    
    public override UInt16 WriteRegisters(UInt16 writeAddress, UInt16s values)
    {
        var id  = NextId(); // TODO: check response id
        
        var cmd = new WriteRegistersCommandFrame(SlaveId, writeAddress, values);
        var hdr = new MbapHeader(id, cmd.Data.Count);
        var frm = new ModbusTcpFrame(hdr, cmd);

        Connection.Transmit(frm.Data);

        var hData = Connection.Receive(MbapHeader.Size).ToArray();
        var rxHdr = new MbapHeader(hData);

        var fData = Connection.Receive(rxHdr.FrameLength).ToArray();
        var rxFrm = WriteRegistersResponseFrame.Parse(fData);

        var verified = cmd.VerifyResponse(rxFrm);

        return verified.NbWritten;
    }

    public override ModbusRegisters ReadWriteRegisters(UInt16 readAddress, UInt16 nbToRead, UInt16 writeAddress, UInt16s registersToWrite)
    {
        var id  = NextId(); // TODO: check response id
        
        var cmd = new ReadWriteRegistersCommandFrame(SlaveId, readAddress, nbToRead, writeAddress, registersToWrite);
        var hdr = new MbapHeader(id, cmd.Data.Count);
        var frm = new ModbusTcpFrame(hdr, cmd);

        Connection.Transmit(frm.Data);

        var hData = Connection.Receive(MbapHeader.Size).ToArray();
        var rxHdr = new MbapHeader(hData);

        var fData = Connection.Receive(rxHdr.FrameLength).ToArray();
        var rxFrm = ReadWriteRegistersResponseFrame.Parse(fData);

        var verified = cmd.VerifyResponse(rxFrm);

        return new ModbusRegisters(readAddress, verified.RegistersRead.ToArray());
    }

}