package com.murion.engine.network.main.packet;

import com.murion.engine.network.utilities.ByteBufUtils;

import io.netty.buffer.ByteBuf;

/**
 * @author _Jordan <jordan.abraham1997@gmail.com>
 */
public class PacketByteBuf {

    /**
     * @author _Jordan <jordan.abraham1997@gmail.com>
     */
    public enum PacketHeader {
        STANDARD, VAR_BYTE, VAR_SHORT;
    }

    /**
     * The bit masks.
     */
    private static final int[] BIT_MASK_OUT = new int[] { 0, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff, 0x7ff, 0xfff, 0x1fff, 0x3fff, 0x7fff, 0xffff, 0x1ffff, 0x3ffff, 0x7ffff, 0xfffff, 0x1fffff, 0x3fffff, 0x7fffff, 0xffffff, 0x1ffffff, 0x3ffffff, 0x7ffffff, 0xfffffff, 0x1fffffff, 0x3fffffff, 0x7fffffff, -1 };

    /**
     * Represents the fixed buffer.
     */
    private ByteBuf buffer;

    /**
     * The bit position.
     */
    private int bitPosition;

    /**
     * Constructs a new {@code PacketByteBuf} object.
     *
     * @param buffer The buffer buffer.
     */
    public PacketByteBuf(ByteBuf buffer) {
        this.buffer = buffer;
    }

    public PacketByteBuf writeByte(int value) {
        buffer.writeByte(value);
        return this;
    }

    public PacketByteBuf writeInt(int value) {
        buffer.writeInt(value);
        return this;
    }

    public PacketByteBuf writeShort(int value) {
        buffer.writeShort(value);
        return this;
    }

    public PacketByteBuf writeIntA(int value) {
        buffer.writeByte(value >> 8);
        buffer.writeByte(value);
        buffer.writeByte(value >> 24);
        buffer.writeByte(value >> 16);
        return this;
    }

    public PacketByteBuf writeIntB(int value) {
        buffer.writeByte(value >> 16);
        buffer.writeByte(value >> 24);
        buffer.writeByte(value);
        buffer.writeByte(value >> 8);
        return this;
    }

    public PacketByteBuf writeShortA(int value) {
        buffer.writeByte(value >> 8);
        buffer.writeByte(value + 128);
        return this;
    }

    public PacketByteBuf writeLEShort(int value) {
        buffer.writeByte(value);
        buffer.writeByte(value >> 8);
        return this;
    }

    public PacketByteBuf writeLEShortA(int value) {
        buffer.writeByte(value + 128);
        buffer.writeByte(value >> 8);
        return this;
    }

    public PacketByteBuf writeByteS(int value) {
        buffer.writeByte(128 - value);
        return this;
    }

    public PacketByteBuf writeByteA(int value) {
        buffer.writeByte(value + 128);
        return this;
    }

    public PacketByteBuf writeSmart(int value) {
        if (value >= 128) {
            buffer.writeShort(value + 32768);
        } else {
            buffer.writeByte(value);
        }
        return this;
    }

    public PacketByteBuf writeBits(int numBits, int value) {
        int bytePos = bitPosition >> 3;
        int bitOffset = 8 - (bitPosition & 7);
        bitPosition += numBits;
        int pos = (bitPosition + 7) / 8;
        buffer.ensureWritable(pos + 1); // pos + 1
        buffer.writerIndex(pos);
        byte b;
        for (; numBits > bitOffset; bitOffset = 8) {
            b = buffer.getByte(bytePos);
            buffer.setByte(bytePos, (byte) (b & ~BIT_MASK_OUT[bitOffset]));
            buffer.setByte(bytePos++, (byte) (b | (value >> (numBits - bitOffset)) & BIT_MASK_OUT[bitOffset]));
            numBits -= bitOffset;
        }
        b = buffer.getByte(bytePos);
        if (numBits == bitOffset) {
            buffer.setByte(bytePos, (byte) (b & ~BIT_MASK_OUT[bitOffset]));
            buffer.setByte(bytePos, (byte) (b | value & BIT_MASK_OUT[bitOffset]));
        } else {
            buffer.setByte(bytePos, (byte) (b & ~(BIT_MASK_OUT[numBits] << (bitOffset - numBits))));
            buffer.setByte(bytePos, (byte) (b | (value & BIT_MASK_OUT[numBits]) << (bitOffset - numBits)));
        }
        return this;
    }

    public PacketByteBuf initBitAccess() {
        bitPosition = buffer.writerIndex() * 8;
        return this;
    }

    public PacketByteBuf finishBitAccess() {
        buffer.writerIndex((bitPosition + 7) / 8);
        return this;
    }

    public PacketByteBuf writeGJString(String string) {
        ByteBufUtils.writeGJString(string, buffer);
        return this;
    }

    public PacketByteBuf writeGJString2(String string) {
        ByteBufUtils.writeGJString2(string, buffer);
        return this;
    }

    public int readInt() {
        return buffer.readInt();
    }

    public int readShort() {
        return buffer.readShort();
    }

    public String readRS2String() {
        return ByteBufUtils.readString(buffer);
    }

    public ByteBuf getBuffer() {
        return buffer;
    }

}