using OpenMetaverse.Rendering;
using Raindrop.Render;
using Raindrop.Tests.MeshingTests;
using UnityEngine;
using Mesh = UnityEngine.Mesh;

//help us see that the terrain mesher works.
namespace Raindrop.Tests.MeshingTests
{
    public class Test_TerrainVisualiser_Simple : MonoBehaviour
    {
        #region params

        public int HeightmapX = 256;
        public int HeightmapY = 256;
        public int TerrainSize = 256;
        public float noiseAmplitude = 10f;
        public float noisePeriod = 10f;

        private int HeightmapX_prev = 256;
        private int HeightmapY_prev = 256;
        private int TerrainSize_prev = 256;
        private float noiseFactor_prev = 10f;
        private float noisePeriod_prev = 10f;
    
        private bool needsupdate = true;
        private bool isWorking = false;

        public MeshFilter MeshFilter;
        public Mesh generatedMesh;

        #endregion

        private void Awake()
        {
            generatedMesh = new Mesh();
            if (MeshFilter is null)
            {
                return;
            }
            MeshFilter.mesh = generatedMesh;

        }

        void Update()
        {
            if (isWorking)
            {
                return;
            }

            bool paramsChanged = (HeightmapX_prev != HeightmapX) ||
                                 (HeightmapY_prev != HeightmapY) ||
                                 (TerrainSize_prev != TerrainSize) || 
                                 (Mathf.Abs(noiseFactor_prev - noiseAmplitude) > 0.01f) ||
                                 (Mathf.Abs(noisePeriod_prev - noisePeriod) > 0.01f);
            if (paramsChanged)
            {
                needsupdate = true;
                HeightmapX_prev = HeightmapX;
                HeightmapY_prev = HeightmapY;
                TerrainSize_prev = TerrainSize;
                noiseFactor_prev = noiseAmplitude;
                noisePeriod_prev = noisePeriod;
            }
        
            if (needsupdate)
            {
                needsupdate = false;
                isWorking = true;
                PerformMeshing(HeightmapX,HeightmapY, TerrainSize, noiseAmplitude);
                isWorking = false;
            }
        }

        private void PerformMeshing(int heightmapXResolution, int heightmapYResolution, int terrainSize, float noiseFactor)
        {
            if (terrainSize < 2 || heightmapXResolution < 2 || heightmapYResolution < 2)
            {
                return;
            }

            var zMap = new float[heightmapXResolution,heightmapYResolution];
            TerrainTestFunctions.GenerateNoiseZMap((uint)heightmapXResolution, (uint)heightmapYResolution, ref zMap, noiseFactor, noisePeriod);
            var mesher = new MeshmerizerR();
            Face face = mesher.TerrainMesh(zMap,0, terrainSize,0,terrainSize);

            UniMesher.MeshFromFace(face, generatedMesh);
        }
    }
}