MultiTerm/MultiTerm.Protocols/Factories/CommunicationProtocolFactory.cs

using MultiTerm.Protocols.Types;

namespace MultiTerm.Protocols.Factories;

/// <summary>
/// Can create <see cref="ICommunicationProtocol"/> instances during runtime.
/// </summary>
public class CommunicationProtocolFactory : ICommunicationProtocolFactory
{
    private readonly Func<IEnumerable<ICommunicationProtocol>> protocolFactory;
    private readonly Func<IEnumerable<IProtocolSettingsViewModel>> settingsViewModelFactory;

    /// <summary>
    /// Constructor of <see cref="CommunicationProtocolFactory"/>.
    /// </summary>
    /// <param name="protocolFactory">function that gets all registered services with Interface <see cref="ICommunicationProtocol"/></param>
    /// <param name="settingsViewModelFactory">function that gets all registered services with Interface <see cref="IProtocolSettingsViewModel"/></param>
    public CommunicationProtocolFactory(Func<IEnumerable<ICommunicationProtocol>> protocolFactory, Func<IEnumerable<IProtocolSettingsViewModel>> settingsViewModelFactory)
    {
        this.protocolFactory = protocolFactory;
        this.settingsViewModelFactory = settingsViewModelFactory;
    }

    /// <summary>
    /// Creates a new <see cref="ICommunicationProtocol"/> and its corresponding <see cref="IProtocolSettingsViewModel"/>.
    /// </summary>
    /// <param name="protocolType"><see cref="ProtocolType"/> of the new <see cref="ICommunicationProtocol"/></param>
    /// <returns>tuple of communication protocol and protocol settings viewmodel</returns>
    public Tuple<ICommunicationProtocol, IProtocolSettingsViewModel> Create(ProtocolType protocolType)
    {
        ICommunicationProtocol protocol;
        IProtocolSettingsViewModel settingsViewModel;

        // get all registered ICommunicationProtocol as IEnumerable
        var registeredProtocols = protocolFactory();

        // get all registered IProtocolSettingsViewModel as IEnumerable
        var registeredSettingsViewModel = settingsViewModelFactory();

        // search for correct type of protocol implementation by ProtocolType
        try
        {
            protocol = registeredProtocols.Where(x => x.ProtocolType == protocolType).First();
        }
        catch (Exception ex)
        {
            throw new NotImplementedException($"'{nameof(CommunicationProtocolFactory)}' cannot create " +
                $"CommunicationProtocol with {nameof(ProtocolType)} {protocolType}", ex);
        }

        // search for correct type of settings View Model implementation by ProtocolType
        try
        {
            settingsViewModel = registeredSettingsViewModel.Where(x => x.ProtocolType == protocolType).First();
        }
        catch (Exception ex)
        {
            throw new NotImplementedException($"'{nameof(CommunicationProtocolFactory)}' cannot create " +
                $"ProtocolSettingsViewModel with {nameof(ProtocolType)} {protocolType}", ex);
        }

        // check if settings viewmodel also implements IProtocolSettings, which it must
        if(settingsViewModel is not IProtocolSettings)
        {
            throw new NotImplementedException($"'{nameof(CommunicationProtocolFactory)}' cannot create " +
                $"CommunicationProtocol since {settingsViewModel.GetType()} does not implement {nameof(IProtocolSettings)}.");
        }

        // return the filled up instances
        return new Tuple<ICommunicationProtocol, IProtocolSettingsViewModel>(protocol, settingsViewModel);
    }

}