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

namespace MoreMountains.Tools
{
    /// <summary>
    /// Add this class to a canvas and it'll automatically reposition TouchPrefabs at the position of touches
    /// You can set a higher TouchProvision if your game gets more than the default number (6) simultaneous touches
    /// Disable/enable this mono for it to stop/work
    /// </summary>
    public class MMDebugTouchDisplay : MonoBehaviour
    {
        [Header("Bindings")]
        /// the canvas to display the TouchPrefabs on
        public Canvas TargetCanvas;

        [Header("Touches")]
        /// the prefabs to instantiate to signify the position of the touches
        public RectTransform TouchPrefab;
        /// the amount of these prefabs to pool and provision
        public int TouchProvision = 6;

        protected List<RectTransform> _touchDisplays;

        /// <summary>
        /// On Start we initialize our pool
        /// </summary>
        protected virtual void Start()
        {
            Initialization();
        }

        /// <summary>
        /// Creates the pool of prefabs
        /// </summary>
        protected virtual void Initialization()
        {
            _touchDisplays = new List<RectTransform>();

            for (int i = 0; i < TouchProvision; i++)
            {
                RectTransform touchDisplay = Instantiate(TouchPrefab);
                touchDisplay.transform.SetParent(TargetCanvas.transform);
                touchDisplay.name = "MMDebugTouchDisplay_" + i;
                touchDisplay.gameObject.SetActive(false);
                _touchDisplays.Add(touchDisplay);
            }

            this.enabled = false;
        }

        /// <summary>
        /// On update we detect touches and move our prefabs at their position
        /// </summary>
        protected virtual void Update()
        {
            DisableAllDisplays();
            DetectTouches();
        }

        /// <summary>
        /// Acts on all touches
        /// </summary>
        protected virtual void DetectTouches()
        {
            for (int i = 0; i < Input.touchCount; ++i)
            {
                _touchDisplays[i].gameObject.SetActive(true);
                _touchDisplays[i].position = Input.GetTouch(i).position;
            }
        }

        /// <summary>
        /// Disables all touch prefabs
        /// </summary>
        protected virtual void DisableAllDisplays()
        {
            foreach(RectTransform display in _touchDisplays)
            {
                display.gameObject.SetActive(false);
            }
        }

        /// <summary>
        /// When this mono gets disabled we turn all our prefabs off
        /// </summary>
        protected virtual void OnDisable()
        {
            DisableAllDisplays();
        }
    }
}