class Advancablebuffer {
    readPos = 0;
    internalBuffer;
    littleEndian = true

    constructor(buffer, useBigEndian)
    {
        this.internalBuffer = buffer;
        this.readPos = 0;
        this.littleEndian = !useBigEndian;
    }

    seek(seekPos)
    {
        this.readPos = seekPos
    }

    readString(numBytes)
    {
        let t = this.internalBuffer.subarray(this.readPos, this.readPos+=numBytes);
        return t.toString();
    }

    readInt8()
    {
        let value = this.internalBuffer.readInt8(this.readPos);
        this.readPos += 1;
        return value;
    }

    readUInt16()
    {
        let value = this.littleEndian ? this.internalBuffer.readUInt16LE(this.readPos) : this.internalBuffer.readUInt16BE(this.readPos);
        this.readPos += 2;
        return value;
    }

    readUInt32()
    {
        let value = this.littleEndian ? this.internalBuffer.readUInt32LE(this.readPos) : this.internalBuffer.readUInt32BE(this.readPos);
        this.readPos += 4;
        return value;
    }

    readBytes()
    {
        let length = this.readUInt32()
        let sub = this.internalBuffer.subarray(this.readPos, this.readPos+=length);
        return sub;
    }

    readNadeoString()
    {
        let length = this.readUInt32()
        if(length >= 0xFFFF)
        {
            return {read:-1, str:""};
        }

        if (length == 0) 
        {
            return {read:0, str:""};
        }

        let outString = this.readString(length);
        return {read:outString.length, str:outString};
    }
}

module.exports = Advancablebuffer;