using System;
using UnityEngine;

namespace Utils {
    public class MapGenerator : MonoBehaviour {
        public DrawMode drawMode;

        public const int ChunkSize = 241;
        [Range(0, 6)] public int levelOfDetail;
        public float noiseScale;

        public int octaves;
        [Range(0, 1)] public float persistance;
        public float lacunarity;

        public int seed;
        public Vector2 offset;
        public float meshHeightMultiplier;
        public AnimationCurve meshHeightCurve;
        
        public bool autoUpdate;

        public TerrainType[] regions;

        public void GenerateMap() {
            float[,] noiseMap = Noise.GenerateNoiseMap(ChunkSize, ChunkSize, seed, noiseScale, octaves, persistance, lacunarity, offset);

            Color[] colorMap = new Color[ChunkSize * ChunkSize];
            for (int y = 0; y < ChunkSize; y++)
            for (int x = 0; x < ChunkSize; x++) {
                float currentHeight = noiseMap[x, y];
                for (var i = 0; i < regions.Length; i++) {
                    if (currentHeight <= regions[i].height) {
                        colorMap[y * ChunkSize + x] = regions[i].color;
                        break;
                    }
                }
            }

            MapDisplay display = FindObjectOfType<MapDisplay>();
            switch (drawMode) {
                case DrawMode.NoiseMap:
                    display.DrawTexture(TextureGenerator.TextureFromHeightMap(noiseMap));
                    break;
                
                case DrawMode.ColorMap:
                    display.DrawTexture(TextureGenerator.TextureFromColorMap(colorMap, ChunkSize, ChunkSize));
                    break;
                
                case DrawMode.Mesh:
                    display.DrawMesh(MeshGenerator.GenerateTerrainMesh(noiseMap, meshHeightMultiplier, meshHeightCurve, levelOfDetail), TextureGenerator.TextureFromColorMap(colorMap, ChunkSize, ChunkSize));
                    break;
            }
        }

        private void OnValidate() {
            lacunarity = Mathf.Clamp(lacunarity, 1, 100000);
            octaves = Mathf.Clamp(octaves, 1, 100000);
        }
    }

    [Serializable]
    public struct TerrainType {
        public string name;
        public float height;
        public Color color;
    }
    
    public enum DrawMode {
        NoiseMap,
        ColorMap,
        Mesh
    }
}