using UnityEngine;

public class MapGenerator : MonoBehaviour
{

    public enum DrawMode { NoiseMap, ColourMap, Mesh};
    public DrawMode drawMode;

    public int mapWidth;
    public int mapHeight;
    public float noiseScale;

    public int octaves;

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

    public int seed;
    public Vector2 offset;

    public bool autoUpdate;

    public TerrainType[] regions;

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

        Color[] colourMap = new Color[mapWidth * mapHeight];

        for(int y=0; y<mapHeight; y++)
        {
            for (int x=0; x<mapWidth; x++)
            {
                float currentHeight = noiseMap[x, y];
                for (int i = 0; i < regions.Length; i++)
                {
                    if(currentHeight <= regions[i].height)
                    {
                        colourMap[y*mapWidth + x] = regions[i].colour;
                        break;
                    }
                }
            }
        }

        MapDisplay display = FindFirstObjectByType<MapDisplay>();
        if(drawMode == DrawMode.NoiseMap)
        {
            display.DrawTexture(TextureGenerator.TextureFromHeightMap(noiseMap));
        } else if (drawMode == DrawMode.ColourMap)
        {
            display.DrawTexture(TextureGenerator.TextureFromColourMap(colourMap, mapWidth, mapHeight));
        }else if(drawMode == DrawMode.Mesh)
        {
            display.DrawMesh(MeshGenerator.GenerateTerrainMesh(noiseMap), TextureGenerator.TextureFromColourMap(colourMap, mapWidth, mapHeight));
        }
    }

    private void OnValidate()
    {
        if (mapWidth < 1)
        {
            mapWidth = 1;
        }
        if (mapHeight < 1)
        {
            mapHeight = 1;
        }

        if (lacunarity < 1)
        {
            lacunarity = 1;
        }

        if(octaves < 0)
        {
            octaves = 0;
        }
    }
}

[System.Serializable]
public struct TerrainType
{
    public string name;
    public float height;
    public Color colour;
}