using System;
using System.Reflection;
using HarmonyLib;

using RobocraftX;
using RobocraftX.Services;
using Svelto.Context;

using TechbloxModdingAPI.App;
using TechbloxModdingAPI.Blocks;
using TechbloxModdingAPI.Tasks;
using TechbloxModdingAPI.Utility;

namespace TechbloxModdingAPI
{
    /// <summary>
    /// The main class of the TechbloxModdingAPI.
    /// Use this to initialize the API before calling it.
    /// </summary>
    public static class Main
    {
        private static Harmony harmony;

        public static bool IsInitialized { 
            get { return harmony != null; }
        }

        private static int referenceCount = 0;

        /// <summary>
        /// Initializes the TechbloxModdingAPI. 
        /// Call this as soon as possible after Techblox starts up.
        /// Ideally, this should be called from your main Plugin class's OnApplicationStart() method.
        /// </summary>
        public static void Init()
        {
            referenceCount++;
            if (referenceCount > 1) { return; }
            if (IsInitialized)
            {
                Logging.LogWarning("TechbloxModdingAPI.Main.Init() called but API is already initialized!");
                return;
            }
            Logging.MetaDebugLog($"Patching Techblox");
            var currentAssembly = Assembly.GetExecutingAssembly();
            harmony = new Harmony(currentAssembly.GetName().Name);
            try
            {
                harmony.PatchAll(currentAssembly);
            }
            catch (Exception e)
            {
                HandleError(e, "Failed to patch Techblox. Attempting to patch to display error...", OnPatchError);
                return;
            }

            try
            {
                // init utility
                Logging.MetaDebugLog($"Initializing Utility");
                Utility.GameState.Init();
                // init block implementors
                Logging.MetaDebugLog($"Initializing Blocks");
                // init input
                Input.FakeInput.Init();
                // init object-oriented classes
                Player.Init();
                Block.Init();
                BlockGroup.Init();
                Wire.Init();
                // init client
                Logging.MetaDebugLog($"Initializing Client");
                Client.Init();
                Game.Init();
                // init UI
                Logging.MetaDebugLog($"Initializing UI");
                Interface.IMGUI.Constants.Init();
                Interface.IMGUI.IMGUIManager.Init();
                // init anti-anticheat
                Logging.MetaDebugLog("Initializing anti-anticheat");
                AntiAntiCheatPatch.Init(harmony);
                Logging.MetaLog($"{currentAssembly.GetName().Name} v{currentAssembly.GetName().Version} initialized");
            }
            catch (Exception e)
            {
                HandleError(e, "Failed to initialize the API! Attempting to patch to display error...", OnInitError);
            }
        }

        /// <summary>
        /// Shuts down & cleans up the TechbloxModdingAPI.
        /// Call this as late as possible before Techblox quits.
        /// Ideally, this should be called from your main Plugin class's OnApplicationQuit() method.
        /// </summary>
        public static void Shutdown()
        {
            if (referenceCount > 0) { referenceCount--; }
            if (referenceCount == 0)
            {
                if (!IsInitialized)
                {
                    Logging.LogWarning("TechbloxModdingAPI.Main.Shutdown() called but API is not initialized!");
                    return;
                }
                Scheduler.Dispose();
                var currentAssembly = Assembly.GetExecutingAssembly();
                harmony.UnpatchAll(currentAssembly.GetName().Name);
                harmony = null;
                Logging.MetaLog($"{currentAssembly.GetName().Name} v{currentAssembly.GetName().Version} shutdown");
            }
        }

        private static void OnPatchError()
        {
            ErrorBuilder.DisplayMustQuitError("Failed to patch Techblox!\n" +
                                              "Make sure you're using the latest version of TechbloxModdingAPI or disable mods if the API isn't released yet.");
        }

        private static void OnInitError()
        {
            ErrorBuilder.DisplayMustQuitError("Failed to initialize the modding API!\n" +
                                              "Make sure you're using the latest version. If you are, please report the error.");
        }
        
        /// <summary>
        /// Handles an init error. Logs the exception, a log message, and allows displaying an error in-game.
        /// </summary>
        /// <param name="e">The exception</param>
        /// <param name="logMsg">The log message</param>
        /// <param name="onInit">The action to run when the game is ready to display error messages</param>
        private static void HandleError(Exception e, string logMsg, Action onInit)
        { //Can't use ErrorBuilder or Logging.LogException (which eventually uses ErrorBuilder) yet
            Logging.Log(e.ToString());
            Logging.LogWarning(logMsg);
            harmony.Patch(AccessTools.Method(typeof(FullGameCompositionRoot), "OnContextInitialized")
                    .MakeGenericMethod(typeof(UnityContext<FullGameCompositionRoot>)),
                new HarmonyMethod(onInit.Method)); //Can't use lambdas here :(
        }
    }
}