using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace ShiftOS.Engine.Terminal
{
    public static class TerminalBackend
    {
        // The line below gets all the terminal commands in... well... the entire ShiftOS.Engine
        public static IEnumerable<TerminalCommand> instances = from t in Assembly.GetExecutingAssembly().GetTypes()
                        where t.IsSubclassOf(typeof(TerminalCommand))
                                 && t.GetConstructor(Type.EmptyTypes) != null
                        select Activator.CreateInstance(t) as TerminalCommand;

        /// <summary>
        /// Runs a terminal command.
        /// </summary>
        /// <param name="command"></param>
        /// <returns>Returns all the output from that command.</returns>
        public static string RunCommand(string command)
        {
            string name;
            try { name = command.Split(' ')[0]; } catch { name = command; }

            var theParams = new string[command.Split(' ').Length - 1];
            Array.Copy(command.Split(' '), 1, theParams, 0, command.Split(' ').Length - 1);

            foreach (TerminalCommand instance in instances)
            {
                if (instance.GetName() == name)
                    return instance.Run(theParams);
            }

            return "The command cannot be found.";
        }

        // An extra function ;)
        private static Type[] GetTypesInNamespace(Assembly assembly, string nameSpace)
        {
            return assembly.GetTypes().Where(t => String.Equals(t.Namespace, nameSpace, StringComparison.Ordinal)).ToArray();
        }
    }
}