/*
 * MIT License
 * 
 * Copyright (c) 2017 Michael VanOverbeek and ShiftOS devs
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

using Microsoft.Scripting.Hosting;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace ShiftOS.Engine
{
    /// <summary>
    /// Mirror, mirror on the wall. Manages a list of types found in ShiftOS-related assemblies.
    /// </summary>
    public static class ReflectMan
    {
        private static Assembly[] asms = null;
        /// <summary>
        /// The list of found assemblies.
        /// </summary>
        public static Assembly[] Asms
        {
            get
            {
                if (asms == null)
                    LoadFiles();
                return asms;
            }
        }

        private static Type[] types = null;
        /// <summary>
        /// The list of found types.
        /// </summary>
        public static Type[] Types
        {
            get
            {
                if (types == null)
                {
                    FindTypes();
                    PythonAPI.Scan();
                }
                return types;
            }
        }

        private static void LoadFiles()
        {
            var ret = new List<Assembly>();
            foreach (var exe in Array.FindAll(System.IO.Directory.GetFiles(Environment.CurrentDirectory), n => n.EndsWith(".exe", true, null) || n.EndsWith(".dll", true, null)))
                try
                {
                    var asm = Assembly.LoadFile(exe);
                    if (asm.GetReferencedAssemblies().Contains("ShiftOS.Engine") || asm.FullName.Contains("ShiftOS.Engine"))
                        ret.Add(asm);
                }
                catch { } // probably not a managed assembly
            asms = ret.ToArray();
        }

        private static void FindTypes()
        {
            var ret = new List<Type>();
            foreach (var asm in Asms)
                ret.AddRange(asm.GetTypes());
            types = ret.ToArray();
        }

        /// <summary>
        /// Add extra types to the ReflectMan array after the scan is complete.
        /// Shouldn't be public, but C# doesn't support "friend".
        /// </summary>
        /// <param name="newtypes">An array of types to append.</param>
        public static void AddTypes(Type[] newtypes)
        {
            var oldlength = types.Length;
            Array.Resize(ref types, oldlength + newtypes.Length);
            newtypes.CopyTo(types, oldlength);
        }
    }

#if DEBUG
    public static class ReflectDebug
    {
        [Command("listalltypes", description = "List all types that were found by ReflectMan. Only present in DEBUG builds of ShiftOS.")]
        public static bool ListAllTypes(Dictionary<string, object> args)
        {
            foreach (var type in ReflectMan.Types)
                Console.WriteLine(type.ToString());
            return true;
        }
    }
#endif
}