using InnovEnergy.Lib.Protocols.Modbus.Protocol.Frames.Accessors;
using static InnovEnergy.Lib.Protocols.Modbus.Protocol.Frames.Constants;
using static InnovEnergy.Lib.Protocols.Modbus.Protocol.FunctionCode;


namespace InnovEnergy.Lib.Protocols.Modbus.Protocol.Frames.Replies;

using UInt16s = IReadOnlyList<UInt16>;

internal class ReadWriteRegistersResponseFrame : ModbusFrame
{
    internal new const Int32 MinSize = 3;

    public MbByte  ByteCount     => Data.ByteAt(2);
    public MbWords RegistersRead => Data.WordsAt(3);

    public ReadWriteRegistersResponseFrame(Byte slave, UInt16s registersRead) : base(ExpectedSize(registersRead.Count))
    {
        if (registersRead.Count > MaxRegs)
            throw new ArgumentOutOfRangeException($"Maximum number of registers ({MaxRegs}) exceeeded!", nameof(registersRead));

        SlaveAddress .Set(slave);
        FunctionCode .Set(ReadWriteMultipleRegisters);
        ByteCount    .Set(2 * registersRead.Count);
        RegistersRead.Set(registersRead);
    }

    internal static Int32 ExpectedSize(Int32 nRegisters) => MinSize + nRegisters * 2;

    private ReadWriteRegistersResponseFrame(Byte[] data) : this (new ArraySegment<Byte>(data))
    { }

    private ReadWriteRegistersResponseFrame(ArraySegment<Byte> data) : base(data)
    {
        if (data.Count < MinSize)
            throw new ArgumentException($"Expecting an array of size {MinSize} or more", nameof(data));

        AssertFunctionCode(ReadWriteMultipleRegisters);

        var expectedSize = ByteCount + MinSize;
        if (data.Count != expectedSize)
            throw new ArgumentException($"Expecting an array of size {expectedSize}", nameof(data));

        if (ByteCount != RegistersRead.Count * 2)
            throw new ArgumentException(nameof(RegistersRead));

    }


    public static ReadWriteRegistersResponseFrame Parse(Byte[] data) => new ReadWriteRegistersResponseFrame(data);
    public static ReadWriteRegistersResponseFrame Parse(ArraySegment<Byte> data) => new ReadWriteRegistersResponseFrame(data);
    public static ReadWriteRegistersResponseFrame Parse(ModbusFrame frame) => new ReadWriteRegistersResponseFrame(frame.Data);
}