using System.Collections.Generic;
using Unity.Collections;
using Unity.Mathematics;
using UnityEngine;

namespace RealityReboot.jelycho {
    [ExecuteInEditMode]
    public class GutRenderer : MonoBehaviour {
        static readonly List<Vector3> s_worldPositions = new(1024);

        [SerializeField] Rope m_Rope;
        [SerializeField] Material m_Material;

        [SerializeField] float3[] m_Positions;

        [SerializeField, Range(3, 128)] int m_Resolution = 16;

        
        [SerializeField] Mesh m_Mesh;

        void Update() {
            if (m_Mesh == null) {
                m_Mesh = new Mesh {
                    name = "GutMesh",
                    indexFormat = UnityEngine.Rendering.IndexFormat.UInt32
                };
                m_Mesh.MarkDynamic();
            }

            if (m_Positions.Length < 2) {
                return;
            }
            
            int segmentCount = m_Positions.Length - 1;
            int vertexCount = m_Resolution * segmentCount;
            int triangleCount = (segmentCount - 1) * m_Resolution * 2;
            
            NativeArray<float3> positions = new(vertexCount, Allocator.Temp);
            NativeArray<float3> normals = new(vertexCount, Allocator.Temp);
            NativeArray<float2> uvs = new(vertexCount, Allocator.Temp);
            NativeArray<int> indices = new(triangleCount * 3, Allocator.Temp);

            for (int i = 0; i < m_Positions.Length - 1; i++) {

            }
            
            m_Mesh.Clear();
            m_Mesh.SetVertices(positions);
            m_Mesh.SetNormals(normals);
            m_Mesh.SetUVs(0, uvs);
            m_Mesh.SetIndices(indices, MeshTopology.Triangles, 0, false);

            Graphics.DrawMesh(m_Mesh, Matrix4x4.identity, m_Material, 0);
        }
    }
}