MultiTerm/MultiTerm.Core/Factories/TerminalViewModelFactory.cs

using MultiTerm.Core.Common;
using MultiTerm.Core.ViewModel;

namespace MultiTerm.Core.Factories;

/// <summary>
/// Can create <see cref="ITerminalViewModel"/> instances during runtime.
/// </summary>
public class TerminalViewModelFactory : ITerminalViewModelFactory
{
    private readonly Func<IEnumerable<ITerminalViewModel>> factory;

    /// <summary>
    /// Constructor of <see cref="TerminalViewModelFactory"/>.
    /// </summary>
    /// <param name="factory">function that gets all registered services with Interface <see cref="ITerminalViewModel"/></param>
    public TerminalViewModelFactory(Func<IEnumerable<ITerminalViewModel>> factory)
    {
        this.factory = factory;
    }

    /// <summary>
    /// Creates a new <see cref="ITerminalViewModel"/>.
    /// </summary>
    /// <param name="viewType"><see cref="TerminalViewType"/> of the new <see cref="ITerminalViewModel"/>. Must be set at creation time for all <see cref="ITerminalViewModel"/></param>
    /// <param name="protocolType"><see cref="ProtocolType"/> of the new <see cref="ITerminalViewModel"/></param>
    /// <returns></returns>
    public ITerminalViewModel Create(TerminalViewType viewType, ProtocolType protocolType)
    {
        ITerminalViewModel output;

        // get all registered TerminalViewModels as IEnumerable
        var registeredViewModels = factory();

        // search for correct type by ViewType which must be set in constructor of all TerminalViewModel Types
        try
        {
            output = registeredViewModels.Where(x => x.ViewType == viewType).First();
        }
        catch (Exception ex)
        {
            throw new NotImplementedException($"'{nameof(TerminalViewModelFactory)}' cannot create Terminal with {nameof(TerminalViewType)} {viewType}", ex);
        }

        // immediately initialize protocol type
        output.ProtocolType = protocolType;

        // return the filled up instance
        return output;
    }
}