using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UIElements;
using BITKit;
using BITKit.UX;
using System.Linq;
using UnityEngine.InputSystem;
using Cysharp.Threading.Tasks;
using System.Text;
using System.IO;
using System.Reflection;
using System.Reflection.Emit;
using UnityEngine.InputSystem.Interactions;
using Label = UnityEngine.UIElements.Label;
// ReSharper disable PossibleMultipleEnumeration

namespace BITKit.Console
{
    public class BITConsole : MonoBehaviour
    {
        [RuntimeInitializeOnLoadMethod]
        private static void Reload()
        {
            Application.logMessageReceivedThreaded += EnqueueLog;
        }
        [BITCommand]
        public static void Console_Exception_Print_StackTrace(int allow)
        {
            exceptionPrintStackTrace = allow is 1;
        }
        private static bool exceptionPrintStackTrace = false;
        private class CommandSelector
        {
            public VisualElement Container { get; set; }
            public int Index
            {
                get => _index;
                set
                {
                    if (_methods.Length is 0)
                    {
                        _index = -1;
                        return;
                    }
                    _index = (value+_methods.Length)%_methods.Length;
                    Rebuild();
                }
            }
            public event Action<MethodInfo> OnSelected; 
            
            private int _index;
            private MethodInfo[] _methods=Array.Empty<MethodInfo>();
            public void Rebuild()
            {
                Container.Clear();
                for (var i = 0; i < _methods.Length; i++)
                {
                    var method = _methods[i];

                    var button = Container.Create<Button>();
                    
                    StringBuilder stringBuilder = new(method.Name);

                    foreach (var parameterInfo in method.GetParameters())
                    {
                        stringBuilder.Append($" {parameterInfo.ParameterType.Name}:{parameterInfo.Name}");
                    }
                    
                    button.clicked+= () =>
                    {
                        OnSelected?.Invoke(method);
                        Rebuild();
                    };
                    
                    button.text = stringBuilder.ToString();
                    
                    Container.Add(button);
                }
                
            }
            public void SetMethods(IEnumerable<MethodInfo> methods)
            {
                if (methods.IsValid())
                {
                    if (_methods.SequenceEqual(methods)) return;
                }
               
                _methods=methods.IsValid()?methods.ToArray():Array.Empty<MethodInfo>();
                if (_methods!.Length is 0)
                {
                    _index = -1;
                }
                Rebuild();
            }
        }
        [BITCommand]
        public static async void Clear()
        {
            await BITApp.SwitchToMainThread();
            singleton.outputString.Clear();
            singleton.text.text = string.Empty;
        }
        private static BITConsole singleton;
        [SerializeField] private UIDocument document;
        [SerializeReference] private InputActionReference toggleAction;

        private static ConcurrentQueue<(string condition, string stackTrace, LogType type)> logQueue = new();
        private static void EnqueueLog(string condition, string stackTrace, LogType type)
        {
            logQueue.Enqueue((condition, stackTrace, type));
        }

        private readonly InputActionGroup _inputActionGroup=new()
        {
            allowGlobalActivation = false
        };
        public int logLineLimit = 64;
        [UXBindPath("commands-container")]
        private VisualElement commandContainer;
        [UXBindPath("TextField")]
        private  TextField textField;
        [UXBindPath("Text")]
        private  Label text;
        [UXBindPath( "context-scrollview")]
        private  ScrollView scrollView;
        private  bool _isRunning;
        private List<string> outputString = new();

        private CommandSelector _commandSelector;
        private void Start()
        {
            UXUtils.Inject(this);
            
            _commandSelector = new()
            {
                Container = commandContainer,
            };
            _commandSelector.OnSelected += x =>
            {
                textField.SetValueWithoutNotify(x.Name);
                textField.Blur();
                textField.Focus();
            };
            
            
            singleton = this;
            
           

            textField.RegisterValueChangedCallback(OnTextFieldValueChanged);
            textField.RegisterCallback<KeyDownEvent>(OnKeyDown);


            text.text = string.Empty;

            
            _inputActionGroup.RegisterCallback(toggleAction,Toggle);
            //_inputActionGroup.RegisterCallback(nextOrPreviousAction, OnNextCommand);
            
            _inputActionGroup.allowInput.AddElement(this);
            
            Toggle(false);
            
            BIT4Log.OnNextLine += OnNextLine;
            
            destroyCancellationToken.Register(() =>
            {
                BIT4Log.OnNextLine -= OnNextLine;
            });

           
        }
        private void OnNextLine()
        {
            if (outputString.Count is not 0 && outputString.Last() != string.Empty)
                outputString.Add(string.Empty);
        }

       private void OnDestroy()
        {
            _inputActionGroup.allowInput.RemoveElement(this);
        }
        public async void Toggle(bool active)
        {
            _commandSelector.SetMethods(null);
            
            document.rootVisualElement.SetActive(active);
            _isRunning = active;
            
            BITAppForUnity.AllowCursor.SetElements(this,active);
            BITInputSystem.AllowInput.SetDisableElements(this,active);
            
            await UniTask.WaitForEndOfFrame(this);
            if (active)
            {
                textField.SetValueWithoutNotify(string.Empty);

                textField.Focus();

                scrollView.ScrollToBottom();
            }
            else
            {
                text.Blur();
            }
        }
        private void OnTextFieldValueChanged(ChangeEvent<string> callback)
        {
            if (string.IsNullOrEmpty(callback.newValue) is false)
            {
                var commands = BITCommands.GetMethodInfos(callback.newValue).ToArray();
                
                _commandSelector.SetMethods(commands);

                commandContainer.SetActive(commands.Length is not 0);
            }
            else
            {
                commandContainer.SetActive(false);
                
                _commandSelector.SetMethods(null);
            }
        }
        private async void OnKeyDown(KeyDownEvent keyDownEvent)
        {
            var nextStop=true;
            switch (keyDownEvent.keyCode)
            {
                case KeyCode.Return:
                    var cmd = textField.text;

                    LogCallback($">{cmd}", string.Empty, LogType.Log);

                    textField.SetValueWithoutNotify(string.Empty);

                    await UniTask.NextFrame();

                    if (destroyCancellationToken.IsCancellationRequested) return;
                    
                    
                    textField.Blur();
                    
                    textField.Focus();

                    BITCommands.Excute(cmd);
                    
                    _commandSelector.SetMethods(null);

                    break;
                case KeyCode.Tab:
                    break;
                case KeyCode.DownArrow when string.IsNullOrEmpty(textField.text) is false:
                    _commandSelector.Index-=1;
                    break;
                case KeyCode.UpArrow when string.IsNullOrEmpty(textField.text) is false:
                    _commandSelector.Index+=1;
                    break;
                default:
                    nextStop = false;
                    break;
            }

            if (nextStop)
            {
                keyDownEvent.StopPropagation();
                keyDownEvent.PreventDefault();
            }
        }
        private void Toggle(InputAction.CallbackContext context)
        {
            switch (context)
            {
                case { interaction: PressInteraction, performed: true }:
                    Toggle(!_isRunning);
                    break;
            }
        }

        private async void LogCallback(string condition, string stackTrace, LogType type)
        {
            try
            {
                switch (type)
                {
                    case LogType.Error:
                        outputString.Add($"<color=red>{condition}</color>");
                        break;
                    case LogType.Warning:
                        outputString.Add($"<color=yellow>{condition}</color>");
                        break;
                    case LogType.Exception:
                        outputString.Add($"<color=red>{condition}</color>");
                        if (exceptionPrintStackTrace)
                            outputString.Add($"<color=red>{stackTrace}</color>");
                        break;
                    default:
                        outputString.Add(condition);
                        break;
                }

                var length = outputString.Count;
                if (length > logLineLimit)
                {
                    outputString = outputString.GetRange(length - logLineLimit, logLineLimit);
                }
                StringBuilder stringBuilder = new();
                outputString.ForEach(x => stringBuilder.AppendLine(x));
                try
                {
                    await BITApp.SwitchToMainThread();
                    scrollView.ScrollToBottomAutomatic();
                    text.text = stringBuilder.ToString();
                    
                }
                catch (OperationCanceledException)
                {
                }
            }
            catch (Exception e)
            {
                Debug.LogException(e);
            }
        }

        private void Update()
        {
            while (logQueue.TryDequeue(out var log))
            {
                LogCallback(log.condition, log.stackTrace, log.type);
            }

            if (_isRunning is false) return;
         
            var pos = textField.worldTransform.GetPosition();
            var size = textField.layout.size;

            commandContainer.style.left = 0;
            commandContainer.style.top = 0;

            pos.y += size.y;
            commandContainer.transform.position = pos;

            commandContainer.style.width = size.x;
        }
    }
}