package electrosphere.server.fluid.manager;


import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;

import org.joml.Vector3f;
import org.joml.Vector3i;

import electrosphere.server.terrain.manager.ServerTerrainChunk;


/**
 * Is a single chunk of terrain on the server
 */
public class ServerFluidChunk {


    /**
     * Number of adjacent arrays
     */
    static final int ARRAY_CT = 27;

    /**
     * Index of the center buffer
     */
    static final int CENTER_BUFF = 13;

    /**
     * Size of a fluid buffer
     */
    static final int BUFFER_SIZE = ServerTerrainChunk.CHUNK_DIMENSION * ServerTerrainChunk.CHUNK_DIMENSION * ServerTerrainChunk.CHUNK_DIMENSION;


    /**
     * The world x coordinate of this chunk
     */
    int worldX;

    /**
     * The world y coordinate of this chunk
     */
    int worldY;

    /**
     * The world z coordinate of this chunk
     */
    int worldZ;


    /**
     * The float view of the center weight buffer
     */
    FloatBuffer weights;

    /**
     * The float view of the center velocity x buffer
     */
    FloatBuffer velocityX;

    /**
     * The float view of the center velocity y buffer
     */
    FloatBuffer velocityY;

    /**
     * The float view of the center velocity z buffer
     */
    FloatBuffer velocityZ;

    /**
     * The array of all adjacent weight buffers for the fluid sim
     */
    public ByteBuffer[] bWeights = new ByteBuffer[ARRAY_CT];

    /**
     * The array of all adjacent velocity x buffers for the fluid sim
     */
    public ByteBuffer[] bVelocityX = new ByteBuffer[ARRAY_CT];

    /**
     * The array of all adjacent velocity y buffers for the fluid sim
     */
    public ByteBuffer[] bVelocityY = new ByteBuffer[ARRAY_CT];

    /**
     * The array of all adjacent velocity z buffers for the fluid sim
     */
    public ByteBuffer[] bVelocityZ = new ByteBuffer[ARRAY_CT];

    /**
     * The array of all adjacent weight buffers for the fluid sim
     */
    public ByteBuffer[] b0Weights = new ByteBuffer[ARRAY_CT];

    /**
     * The array of all adjacent velocity x buffers for the fluid sim
     */
    public ByteBuffer[] b0VelocityX = new ByteBuffer[ARRAY_CT];

    /**
     * The array of all adjacent velocity y buffers for the fluid sim
     */
    public ByteBuffer[] b0VelocityY = new ByteBuffer[ARRAY_CT];

    /**
     * The array of all adjacent velocity z buffers for the fluid sim
     */
    public ByteBuffer[] b0VelocityZ = new ByteBuffer[ARRAY_CT];

    /**
     * The chunk mask -- Stores which adjacent chunks are populated and which aren't
     */
    public int chunkMask;

    /**
     * Constructor
     * @param worldX The world x coordinate
     * @param worldY The world y coordinate
     * @param worldZ The world z coordinate
     */
    public ServerFluidChunk(int worldX, int worldY, int worldZ) {
        this.worldX = worldX;
        this.worldY = worldY;
        this.worldZ = worldZ;

        //allocate
        this.bWeights[CENTER_BUFF] = ByteBuffer.allocateDirect(BUFFER_SIZE * 4);
        this.bVelocityX[CENTER_BUFF] = ByteBuffer.allocateDirect(BUFFER_SIZE * 4);
        this.bVelocityY[CENTER_BUFF] = ByteBuffer.allocateDirect(BUFFER_SIZE * 4);
        this.bVelocityZ[CENTER_BUFF] = ByteBuffer.allocateDirect(BUFFER_SIZE * 4);
        this.b0Weights[CENTER_BUFF] = ByteBuffer.allocateDirect(BUFFER_SIZE * 4);
        this.b0VelocityX[CENTER_BUFF] = ByteBuffer.allocateDirect(BUFFER_SIZE * 4);
        this.b0VelocityY[CENTER_BUFF] = ByteBuffer.allocateDirect(BUFFER_SIZE * 4);
        this.b0VelocityZ[CENTER_BUFF] = ByteBuffer.allocateDirect(BUFFER_SIZE * 4);

        //order
        this.bWeights[CENTER_BUFF].order(ByteOrder.LITTLE_ENDIAN);
        this.bVelocityX[CENTER_BUFF].order(ByteOrder.LITTLE_ENDIAN);
        this.bVelocityY[CENTER_BUFF].order(ByteOrder.LITTLE_ENDIAN);
        this.bVelocityZ[CENTER_BUFF].order(ByteOrder.LITTLE_ENDIAN);
        this.b0Weights[CENTER_BUFF].order(ByteOrder.LITTLE_ENDIAN);
        this.b0VelocityX[CENTER_BUFF].order(ByteOrder.LITTLE_ENDIAN);
        this.b0VelocityY[CENTER_BUFF].order(ByteOrder.LITTLE_ENDIAN);
        this.b0VelocityZ[CENTER_BUFF].order(ByteOrder.LITTLE_ENDIAN);

        //get float view
        this.weights = this.bWeights[CENTER_BUFF].asFloatBuffer();
        this.velocityX = this.bVelocityX[CENTER_BUFF].asFloatBuffer();
        this.velocityY = this.bVelocityY[CENTER_BUFF].asFloatBuffer();
        this.velocityZ = this.bVelocityZ[CENTER_BUFF].asFloatBuffer();
    }

    /**
     * Gets the world x coordinate
     * @return The world x coordinate
     */
    public int getWorldX() {
        return worldX;
    }

    /**
     * Gets the world y coordinate
     * @return The world y coordinate
     */
    public int getWorldY() {
        return worldY;
    }

    /**
     * Gets the world z coordinate
     * @return The world z coordinate
     */
    public int getWorldZ() {
        return worldZ;
    }

    /**
     * Gets the world position of this terrain chunk as a joml Vector
     * @return The vector
     */
    public Vector3i getWorldPosition(){
        return new Vector3i(worldX,worldY,worldZ);
    }

    /**
     * Gets the weights buffer
     * @return The weight buffer
     */
    public FloatBuffer getWeights() {
        return weights;
    }

    /**
     * Gets the weight of a voxel at a poisiton
     * @param localPosition The local position
     * @return The weight of the specified voxel
     */
    public float getWeight(Vector3i localPosition){
        return getWeight(localPosition.x,localPosition.y,localPosition.z);
    }

    /**
     * Gets the weight of a voxel at a poisiton
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @return The weight of the specified voxel
     */
    public float getWeight(int x, int y, int z){
        return weights.get(this.IX(x,y,z));
    }

    /**
     * Sets a weight
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @param weight The weight
     */
    public void setWeight(int x, int y, int z, float weight){
        weights.put(this.IX(x,y,z),weight);
    }

    /**
     * Gets the velocity x buffer
     * @return The velocity x buffer
     */
    public FloatBuffer getVelocityX() {
        return velocityX;
    }

    /**
     * Gets the x velocity at the point
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @return The x velocity at the point
     */
    public float getVelocityX(int x, int y, int z){
        return velocityX.get(this.IX(x, y, z));
    }


    /**
     * Sets the velocity x buffer
     * @param velocityX The velocity x buffer
     */
    public void setVelocityX(FloatBuffer velocityX) {
        this.velocityX = velocityX;
    }

    /**
     * Sets the x velocity at the point
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @param velocity The x velocity
     */
    public void setVelocityX(int x, int y, int z, float velocity){
        this.velocityX.put(this.IX(x,y,z),velocity);
    }

    /**
     * Gets the velocity y buffer
     * @return The velocity y buffer
     */
    public FloatBuffer getVelocityY() {
        return velocityY;
    }
    
    /**
     * Gets the y velocity at the point
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @return The y velocity at the point
     */
    public float getVelocityY(int x, int y, int z){
        return velocityY.get(this.IX(x, y, z));
    }

    /**
     * Sets the velocity y buffer
     * @param velocityY The velocity y buffer
     */
    public void setVelocityY(FloatBuffer velocityY) {
        this.velocityY = velocityY;
    }

    /**
     * Sets the y velocity at the point
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @param velocity The y velocity
     */
    public void setVelocityY(int x, int y, int z, float velocity){
        this.velocityY.put(this.IX(x,y,z),velocity);
    }


    /**
     * Gets the velocity z buffer
     * @return The velocity z buffer
     */
    public FloatBuffer getVelocityZ() {
        return velocityZ;
    }

    /**
     * Gets the z velocity at the point
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @return The z velocity at the point
     */
    public float getVelocityZ(int x, int y, int z){
        return velocityZ.get(this.IX(x, y, z));
    }

    /**
     * Sets the velocity z buffer
     * @param velocityZ The velocity z buffer
     */
    public void setVelocityZ(FloatBuffer velocityZ) {
        this.velocityZ = velocityZ;
    }

    /**
     * Sets the z velocity at the point
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @param velocity The z velocity
     */
    public void setVelocityZ(int x, int y, int z, float velocity){
        this.velocityZ.put(this.IX(x,y,z),velocity);
    }

    /**
     * Gets the velocity at a given point as a vector3f
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @return The velocity
     */
    public Vector3f getVelocity(int x, int y, int z){
        int index = this.IX(x,y,z);
        return new Vector3f(
            velocityX.get(index),
            velocityY.get(index),
            velocityZ.get(index)
        );
    }

    //set a velocity at a given x, y, and z given three ints
    /**
     * Sets the full velocity at a given point
     * @param x The x coordinate
     * @param y The y coordinate
     * @param z The z coordinate
     * @param velX The x component of the velocity
     * @param velY The y component of the velocity
     * @param velZ The z component of the velocity
     */
    public void setVelocity(int x, int y, int z, float velX, float velY, float velZ){
        int index = this.IX(x,y,z);
        velocityX.put(index, velX);
        velocityY.put(index, velY);
        velocityZ.put(index, velZ);
    }

    /**
     * Gets the inddex into the buffer
     * @param x The x position
     * @param y The y position
     * @param z The z position
     * @return The index
     */
    public int IX(int x, int y, int z){
        return x * ServerTerrainChunk.CHUNK_DIMENSION * ServerTerrainChunk.CHUNK_DIMENSION + y * ServerTerrainChunk.CHUNK_DIMENSION  + z;
    }

    /**
     * Gets the chunk mask for this chunk
     * @return The chunk mask
     */
    public int getChunkMask(){
        return this.chunkMask;
    }


}