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 bool _countsMatch;

        protected LineRenderer _lineRenderer;

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

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

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

        /// <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 (var 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;
        }
    }
}