using System.Collections.Generic;
using Unity.Mathematics;
using UnityEngine;
using UnityEngine.Splines;
#if UNITY_EDITOR
using UnityEditor;
#endif

namespace sc.splinemesher.pro.examples
{
    public class ProceduralSplines : MonoBehaviour
    {
        public SplineContainer splineContainer;

        [Min(1)] public int count = 5;
        public float width = 1f;
        public float length = 1f;

        private void Reset()
        {
            splineContainer = GetComponent();
            if (!splineContainer) splineContainer = gameObject.AddComponent();
            
            GenerateSplines();
        }

        public void GenerateSplines()
        {
            int currentSplineCount = splineContainer.Splines.Count;
            
            //Create a row of splines
            float widthOffset = 0;
            for (int i = 0; i < count; i++)
            {
                BezierKnot[] knots = new BezierKnot[2];

                for (int j = 0; j < knots.Length; j++)
                {
                    float3 position = (math.forward() * (j * length));
                    position.x += widthOffset;
                    
                    knots[j] = new BezierKnot(position, float3.zero, float3.zero, quaternion.identity);
                }
                widthOffset += width;
                
                Spline spline = new Spline(knots);

                //Spline already exists in container, copy new spline into it.
                if (i < currentSplineCount)
                {
                    splineContainer.Splines[i].Copy(spline);
                }
                //Creating more splines than exist in the container, add it as new.
                else
                {
                    splineContainer.AddSpline(spline);
                }
            }

            //If the "count" is lower, the container may still contain more splines than desired (likely created before).
            currentSplineCount = splineContainer.Splines.Count;
            if (count < currentSplineCount) { //Delete any excess splines (loop backwards to avoid index shifting issues). for (int i = currentSplineCount - 1; i >= count; i--)
                {
                    splineContainer.RemoveSplineAt(i);
                }
            }
        }
    }

//Not related to this example, but this'll simply call Rebuild when any value changes in the inspector.
//It's not possible to use OnValidate as a Spline Mesher will perform actions that are not allowed when called from OnValidate
#if UNITY_EDITOR
    [CustomEditor(typeof(ProceduralSplines))]
    public class ProceduralSplinesEditor : Editor
    {
        public override void OnInspectorGUI()
        {
            EditorGUI.BeginChangeCheck();

            base.OnInspectorGUI();

            if (EditorGUI.EndChangeCheck())
            {
                foreach (var m_target in targets)
                    ((ProceduralSplines)m_target).GenerateSplines();
            }
        }
    }
#endif
}