class gbxHeader {

    has_magic = true
    version = -1
    format = -1
    compressionofRefTable = -1
    compressionOfrefBofy = -1
    compressionTextFlag = ''
    id = -1
    userData = []
    numNodes = 0

    is_vaild = false

    parse(buff)
    {
        let header_magic = buff.readString(3);

        if (header_magic != 'GBX')
        {
            console.log("Header Magic Mismatch: " + header_magic);
            return
        }
        this.has_magic = true

        this.version = buff.readUInt16();
        console.log(this.version)

        if (this.version < 5 || this.version >7 )
        {
            console.log("Unsupported version")
            return;
        }

        this.format = buff.readInt8();
        if (this.format != 66)
        {
            console.log("Unsupported format")
            return;
        }

        this.compressionofRefTable = buff.readInt8();

        if (this.compressionofRefTable != 67 && this.compressionofRefTable != 85)
        {
            console.log("Unsupported compression format, Ref")
            return;
        }

        this.compressionofRefBody = buff.readInt8();
        if (this.compressionofRefBody != 67 && this.compressionofRefBody != 85)
        {
            console.log("Unsupported compression format, Body")
            return;
        }

        this.compressionTextFlag = '';
        if (this.version >= 4)
        {
            this.compressionTextFlag = buff.readString(1);
        }

        this.id = buff.readUInt32();
        console.log(this.id)

        if (this.version >=6)
        {
            this.userData = buff.readBytes();
        }

        this.numNodes = buff.readUInt32();

        this.is_vaild = true
    }
}


module.exports = gbxHeader;