namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus;

/// <summary>
///     Modbus TCP driver configuration. Bound from the driver's <c>DriverConfig</c> JSON at
///     <c>DriverHost.RegisterAsync</c>. Every register the driver exposes appears in
///     <see cref="Tags"/>; names become the OPC UA browse name + full reference.
/// </summary>
public sealed class ModbusDriverOptions
{
    public string Host { get; init; } = "127.0.0.1";
    public int Port { get; init; } = 502;
    public byte UnitId { get; init; } = 1;
    public TimeSpan Timeout { get; init; } = TimeSpan.FromSeconds(2);

    /// <summary>Pre-declared tag map. Modbus has no discovery protocol — the driver returns exactly these.</summary>
    public IReadOnlyList<ModbusTagDefinition> Tags { get; init; } = [];
}

/// <summary>
///     One Modbus-backed OPC UA variable. Address is zero-based (Modbus spec numbering, not
///     the documentation's 1-based coil/register conventions).
/// </summary>
/// <param name="Name">
///     Tag name, used for both the OPC UA browse name and the driver's full reference. Must be
///     unique within the driver.
/// </param>
/// <param name="Region">Coils / DiscreteInputs / InputRegisters / HoldingRegisters.</param>
/// <param name="Address">Zero-based address within the region.</param>
/// <param name="DataType">Logical data type. Int16/UInt16 = single register; Int32/UInt32/Float32 = two registers big-endian.</param>
/// <param name="Writable">When true and Region supports writes (Coils / HoldingRegisters), IWritable routes writes here.</param>
public sealed record ModbusTagDefinition(
    string Name,
    ModbusRegion Region,
    ushort Address,
    ModbusDataType DataType,
    bool Writable = true);

public enum ModbusRegion { Coils, DiscreteInputs, InputRegisters, HoldingRegisters }
public enum ModbusDataType { Bool, Int16, UInt16, Int32, UInt32, Float32 }