package com.comphenix.protocol.wrappers;

import com.comphenix.protocol.reflect.EquivalentConverter;
import com.comphenix.protocol.reflect.FuzzyReflection;
import com.comphenix.protocol.reflect.accessors.Accessors;
import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
import com.comphenix.protocol.reflect.accessors.FieldAccessor;
import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
import com.comphenix.protocol.utility.MinecraftReflection;
import com.google.common.base.Objects;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.List;

/**
 * Represents a ChunkCoordIntPair.
 * @author Kristian
 */
public class ChunkCoordIntPair {
    private static Class<?> COORD_PAIR_CLASS = MinecraftReflection.getChunkCoordIntPair();
    private static ConstructorAccessor COORD_CONSTRUCTOR;
    private static FieldAccessor COORD_X;
    private static FieldAccessor COORD_Z;
    
    // Use protected members, like Bukkit
    protected final int chunkX;
    protected final int chunkZ;
    
    /**
     * Construct a new chunk coord int pair.
     * @param x - the x index of the chunk.
     * @param z - the z index of the chunk.
     */
    public ChunkCoordIntPair(int x, int z) {
        this.chunkX = x;
        this.chunkZ = z;
    }
    
    /**
     * Retrieve the chunk index in the x-dimension.
     * <p>
     * This is the number of adjacent chunks to (0, 0), not a block coordinate.
     * @return The x chunk index.
     */
    public int getChunkX() {
        return chunkX;
    }
    
    /**
     * Retrieve the chunk index in the z-dimension.
     * <p>
     * This is the number of adjacent chunks to (0, 0), not a block coordinate.
     * @return The z chunk index.
     */
    public int getChunkZ() {
        return chunkZ;
    }
    
    /**
     * Used to convert between NMS ChunkPosition and the wrapper instance.
     * @return A new converter.
     */
    public static EquivalentConverter<ChunkCoordIntPair> getConverter() {
        return new EquivalentConverter<ChunkCoordIntPair>() {
            @Override
            public Object getGeneric(ChunkCoordIntPair specific) {
                if (COORD_CONSTRUCTOR == null) {
                    COORD_CONSTRUCTOR = Accessors.getConstructorAccessor(COORD_PAIR_CLASS, int.class, int.class);
                }
                
                return COORD_CONSTRUCTOR.invoke(specific.chunkX, specific.chunkZ);
            }
            
            @Override
            public ChunkCoordIntPair getSpecific(Object generic) {
                if (MinecraftReflection.isChunkCoordIntPair(generic)) {
                    if (COORD_X == null || COORD_Z == null) {
                        FuzzyReflection fuzzy = FuzzyReflection.fromClass(COORD_PAIR_CLASS, true);
                        List<Field> fields = fuzzy.getFieldList(FuzzyFieldContract
                                .newBuilder()
                                .banModifier(Modifier.STATIC)
                                .typeExact(int.class)
                                .build());
                        COORD_X = Accessors.getFieldAccessor(fields.get(0));
                        COORD_Z = Accessors.getFieldAccessor(fields.get(1));
                    }
                    return new ChunkCoordIntPair((Integer) COORD_X.get(generic), (Integer) COORD_Z.get(generic));
                }
                
                // Otherwise, return NULL
                return null;
            }

            @Override
            public Class<ChunkCoordIntPair> getSpecificType() {
                return ChunkCoordIntPair.class;
            }
        };
    }
    
    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        
        // Only compare objects of similar type
        if (obj instanceof ChunkCoordIntPair) {
            ChunkCoordIntPair other = (ChunkCoordIntPair) obj;
            return chunkX == other.chunkX && chunkZ == other.chunkZ;
        }
        return false;
    }
    
    @Override
    public int hashCode() {
        return Objects.hashCode(chunkX, chunkZ);
    }

    @Override
    public String toString() {
        return "ChunkCoordIntPair [x=" + chunkX + ", z=" + chunkZ + "]";
    }
}