using Sandbox.Definitions;
using Sandbox.Engine.Networking;
using Sandbox.Game.World;
using Sandbox.ModAPI;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using VRage.Game;
using VRage.Game.GUI;

namespace SeamlessClientPlugin.SeamlessTransfer
{
    public static class ModLoader
    {
        /*  Mod loader should download and load missing mods for target server, and unload ones that arent needed
         * 
         * Sandbox.Game.World.MyScriptManager.LoadData() is where modded scripts get loaded and added
         * Sandbox.Game.World.MySession() calls MyDefinitionManager.Static.LoadData(mods); which loads mod data files
         * 
         * 
         *  Need to be called in the following order: 
         *  ScriptManager.Init(checkpoint.ScriptManagerData);
	     *  MyDefinitionManager.Static.LoadData(checkpoint.Mods);
	     *  PreloadModels(sector);
         * 
         * 
         */


        //Mods that are currently loaded in this instance.
        private static List<MyObjectBuilder_Checkpoint.ModItem> CurrentLoadedMods = new List<MyObjectBuilder_Checkpoint.ModItem>();




        //Mods that we need to Load
        private static List<MyObjectBuilder_Checkpoint.ModItem> TargetLoadMods = new List<MyObjectBuilder_Checkpoint.ModItem>();

        //Mods that we need to UnLoad
        private static List<MyObjectBuilder_Checkpoint.ModItem> TargetUnLoadMods = new List<MyObjectBuilder_Checkpoint.ModItem>();


        private static bool FinishedDownloadingMods = false;
        private static bool DownloadSuccess = false;

        private static DateTime DownloadTimeout;

        private static MethodInfo PrepareBaseSession = typeof(MySession).GetMethod("PreloadModels", BindingFlags.Static | BindingFlags.NonPublic);
        private static FieldInfo ScriptManager = typeof(MySession).GetField("ScriptManager", BindingFlags.Instance | BindingFlags.Public);
       






        public static void DownloadNewMods(List<MyObjectBuilder_Checkpoint.ModItem> Target)
        {
            CurrentLoadedMods = MySession.Static.Mods;
        


            //Loop through our current mods
            foreach(var mod in CurrentLoadedMods)
            {
                if (!Target.Contains(mod))
                    TargetUnLoadMods.Add(mod);
            }


            //Loop through our TargetMods
            foreach(var mod in Target)
            {
                if (!CurrentLoadedMods.Contains(mod))
                    TargetLoadMods.Add(mod);
            }


            DownloadTimeout = DateTime.Now + TimeSpan.FromMinutes(5);
            SeamlessClient.TryShow("Downloading New Mods");
            MyWorkshop.DownloadModsAsync(TargetLoadMods, ModDownloadingFinished);

        }

        private static void ModDownloadingFinished(bool Success)
        {
            if (Success)
            {
                SeamlessClient.TryShow("Mod Downloading Finished!");
                FinishedDownloadingMods = true;
                DownloadSuccess = true;
                //May need to wait seamless loading if mods have yet to finish downloading
            }
            else
            {
                DownloadSuccess = false;
                FinishedDownloadingMods = true;
            }
        }


        public static void ReadyModSwitch(MyObjectBuilder_Checkpoint checkpoint, MyObjectBuilder_Sector sector)
        {
           
            while (!FinishedDownloadingMods)
            {

                //Break out of loop
                if (DownloadTimeout < DateTime.Now)
                    break;


                Thread.Sleep(20);
            }

            FinishedDownloadingMods = false;

            //Skip mod switch
            if (!DownloadSuccess)
                return;

         

            //Create new script manager?
            ScriptManager.SetValue(MySession.Static, new MyScriptManager());


            MyGuiTextures.Static.Unload();
            MySession.Static.ScriptManager.Init(checkpoint.ScriptManagerData);
            MyDefinitionManager.Static.LoadData(TargetServerMods);
            PrepareBaseSession.Invoke(null, new object[] { sector });


            MyLocalCache.PreloadLocalInventoryConfig();


            //SeamlessClient.TryShow("Finished transfering!");
            

           // PrepareBaseSession.Invoke(MySession.Static, new object[] { TargetServerMods, null });


        }


        private static void UnloadOldScripts()
        {
            //	MySandboxGame.Log.WriteLine(string.Format("Script loaded: {0}", value.FullName));
            int amount = 0;
            foreach (var mod in TargetUnLoadMods)
            {
               var val = MySession.Static.ScriptManager.Scripts.FirstOrDefault(x => x.Value.FullName.Contains(mod.PublishedFileId.ToString()));
               MySession.Static.ScriptManager.Scripts.Remove(val.Key);

                amount++;
            }

            SeamlessClient.TryShow($"Removed {amount} old scripts!");



        }





    }
}