using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

namespace MoreMountains.Tools
{
    /// <summary>
    /// A class used to handle the display of a debug log tab in a MMDebugMenu
    /// </summary>
    public class MMDebugMenuDebugTab : MonoBehaviour
    {
        /// the scrollrect where the log will be displayed
        public ScrollRect DebugScrollRect;
        /// the text container
        public Text DebugText;
        /// the prompt input
        public InputField CommandPrompt;
        /// a decorative prompt character
        public Text CommandPromptCharacter;
        /// whether or not the touch screen is visible
        public bool TouchScreenVisible = false;
        protected TouchScreenKeyboard _touchScreenKeyboard;
        protected RectTransform _rectTransform;
        protected float _mobileMenuOffset = -1000f;
        protected bool _touchScreenVisibleLastFrame;

        /// <summary>
        /// On awake we prepare our prompt listener
        /// </summary>
        protected virtual void Awake()
        {
            MMDebug.MMDebugLogEvent.Register(OnMMDebugLogEvent);
            DebugText.text = "";
            _rectTransform = this.gameObject.GetComponent<RectTransform>();

            CommandPrompt.onEndEdit.AddListener(val =>
            {
                CommandPrompt.text = "";
                if (val != "")
                {
                    MMDebug.DebugLogCommand(val);
                }                
            });
        }

        /// <summary>
        /// if the mobile touchscreen is open, we move away
        /// </summary>
        protected virtual void Update()
        {
            TouchScreenVisible = TouchScreenKeyboard.visible;

            if (TouchScreenVisible)
            {
                _rectTransform.MMSetBottom(650f);
            }
            else
            {
                _rectTransform.MMSetBottom(0f);
            }
        }

        /// <summary>
        /// on late update we scroll to the bottom if needed
        /// </summary>
        protected virtual void LateUpdate()
        {
            if (_touchScreenVisibleLastFrame != TouchScreenVisible)
            {
                StartCoroutine(ScrollToLogBottomCo());
            }
            _touchScreenVisibleLastFrame = TouchScreenVisible;
        }

        /// <summary>
        /// Scrolls to the bottom on enable
        /// </summary>
        protected virtual void OnEnable()
        {
            StartCoroutine(ScrollToLogBottomCo());
        }

        /// <summary>
        /// when we get a new log event, we update our text and scroll to the bottom
        /// </summary>
        /// <param name="item"></param>
        protected virtual void OnMMDebugLogEvent(MMDebug.DebugLogItem item)
        {
            DebugText.text = MMDebug.LogHistoryText;
            if (this.gameObject.activeInHierarchy)
            {
                StartCoroutine(ScrollToLogBottomCo());
            }            
        }

        /// <summary>
        /// A coroutine used to scroll to the bottom
        /// </summary>
        /// <returns></returns>
        protected virtual IEnumerator ScrollToLogBottomCo()
        {
            yield return new WaitForEndOfFrame();
            DebugScrollRect.normalizedPosition = Vector2.zero;
        }

        /// <summary>
        /// Stops listening for events
        /// </summary>
        public virtual void OnDestroy()
        {
            MMDebug.MMDebugLogEvent.Unregister(OnMMDebugLogEvent);
        }
    }
}