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

namespace MoreMountains.Tools
{
    /// <summary>
    /// This component, added to a line renderer, will let you fill a list of transforms, and bind their positions to the linerenderer's positions.
    /// </summary>
    [RequireComponent(typeof(LineRenderer))]
    public class MMLineRendererDriver : MonoBehaviour
    {
        [Header("Position Drivers")]

        /// the list of targets - their quantity has to match the LineRenderer's positions count
        public List<Transform> Targets;
        /// whether or not to keep both in sync at update
        public bool BindPositionsToTargetsAtUpdate = true;

        [Header("Binding")]

        /// a test button
        [MMInspectorButton("Bind")]
        public bool BindButton;

        protected LineRenderer _lineRenderer;
        protected bool _countsMatch = false;

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

        /// <summary>
        /// Grabs the line renderer, tests counts
        /// </summary>
        protected virtual void Initialization()
        {
            _lineRenderer = this.gameObject.GetComponent<LineRenderer>();
            _countsMatch = CheckPositionCounts();
            if (!_countsMatch)
            {
                Debug.LogWarning(this.name + ", MMLineRendererDriver's Targets list doesn't have the same amount of entries as the LineRender's Positions array. It won't work.");
            }
        }

        /// <summary>
        /// On Update we bind our positions to targets if needed
        /// </summary>
        protected virtual void Update()
        {
            if (BindPositionsToTargetsAtUpdate)
            {
                BindPositionsToTargets();
            }
        }

        /// <summary>
        /// A method meant to be called by the inspector button
        /// </summary>
        protected virtual void Bind()
        {
            Initialization();
            BindPositionsToTargets();
        }

        /// <summary>
        /// Goes through all the targets and assigns their positions to the LineRenderer's positions
        /// </summary>
        public virtual void BindPositionsToTargets()
        {
            if (!_countsMatch)
            {
                return;
            }

            for (int i = 0; i < Targets.Count; i++)
            {
                _lineRenderer.SetPosition(i, Targets[i].position);
            }
        }

        /// <summary>
        /// Makes sure the counts match
        /// </summary>
        /// <returns></returns>
        protected virtual bool CheckPositionCounts()
        {
            return Targets.Count == _lineRenderer.positionCount;
        }
    }
}