using System.Threading;
using System.Threading.Tasks;

namespace EM.LowLevel
{
    /// <summary>
    ///   Generic high-level controller that composes a PortStream, an ICommandBuilder and an
    ///   IDataDecoder to provide a complete peripheral control workflow.
    /// </summary>
    /// <typeparam name="TPort">
    ///   Concrete transport deriving from PortStream
    /// </typeparam>
    /// <typeparam name="TBuilder">
    ///   Concrete command builder
    /// </typeparam>
    /// <typeparam name="TDecoder">
    ///   Concrete data decoder
    /// </typeparam>
    public interface IPortController<TPort, TBuilder, TDecoder> where TPort: PortStream where TBuilder: ICommandBuilder
        where TDecoder: IDataDecoder
    {

        TBuilder CommandBuilder { get; }

        TDecoder Decoder { get; }

        TPort Port { get; }

        /// <summary>
        ///   Close the underlying port.
        /// </summary>
        void Close();

        /// <summary>
        ///   Ensure the underlying port is opened and ready (delegates to Port.OpenAsync).
        /// </summary>
        ValueTask OpenAsync(CancellationToken cancellationToken = default);

        /// <summary>
        ///   Build a command, send it via the port and decode the response into a model.
        /// </summary>
        ValueTask<TResponse> RoundTripAsync<TCommand, TResponse>(
                             TCommand command,
                             CancellationToken cancellationToken = default)
            where TCommand: notnull;

        /// <summary>
        ///   Build a command and send it without expecting a typed response.
        /// </summary>
        ValueTask WriteAsync<TCommand>(TCommand command, CancellationToken cancellationToken = default)
            where TCommand: notnull;

    }
}