Connected.Host/TomPIT.Connected/Program.cs

using System.Reflection;
using TomPIT.Connected.Configuration;

namespace TomPIT.Connected
{
	public static class Program
	{
		public static void Main(params string[] args)
		{
			SysConfiguration.Build();

			Start(ParseArguments(args));
		}

		private static void Start(Dictionary<string, string> args)
		{
			foreach (var microService in SysConfiguration.MicroServices)
				LoadMicroServiceAssembly(microService);

			if (Type.GetType(SysConfiguration.Start) is not Type startupType)
				throw new Exception($"Cannot resolve startup type. ({SysConfiguration.Start}).");

			if (startupType.GetMethod("ConfigureAsync", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic) is not MethodInfo configureMethod)
				throw new Exception($"ConfigureAsync does not exists in the startup type {startupType}. Startup must have static 'async Task ConfigureAsync(params string[] args)' method.");

			if (configureMethod.Invoke(null, new object[] { args }) is not Task task)
				throw new Exception($"ConfigureAsync of type {startupType} must return Task.");

			task.ConfigureAwait(false);

			task.GetType().GetProperty("Result")?.GetValue(task);
		}

		private static Assembly? LoadMicroServiceAssembly(MicroServiceDescriptor descriptor)
		{
			var assemblyFile = descriptor.Name.EndsWith(".dll") ? descriptor.Name : $"{descriptor.Name}.dll";

			foreach (var location in SysConfiguration.Locations)
			{
				var assemblyPath = Path.Combine(location, assemblyFile);

				if (File.Exists(assemblyPath))
					return Assembly.LoadFrom(assemblyPath);
			}

			return Assembly.Load(AssemblyName.GetAssemblyName(assemblyFile));
		}

		private static Dictionary<string, string> ParseArguments(params string[] args)
		{
			var result = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);

			foreach (var i in args)
			{
				var tokens = i.Split('=', 2);

				if (tokens.Length == 1)
					result.Add(tokens[0].Trim(), string.Empty);
				else
					result.Add(tokens[0].Trim(), tokens[1].Trim());
			}

			return result;
		}

	}
}