Reading contents of Word, PDF file

[cnshum]

i have this use case where i need to read the contents of CV/resume uploaded by users and pass it to a LLM to extract the skills. Currently, I am only able to do so using a txt file (refer to the below code).  But when i use this code on a pdf or word file, the contents are all weird symbols. Can anyone point me in the right direction?

code:

extractSkillsFromCV: function() {

        var tableSysId = this.getParameter('sysparm_tableSysId');

        var grAttach = new GlideRecord("sys_attachment");

        grAttach.addEncodedQuery("table_sys_id=" + tableSysId);

        grAttach.query();

        if(grAttach.next()){

            var document;

            var attach = new GlideSysAttachment().getContentStream(grAttach.sys_id);

            var reader = new GlideTextReader(attach);

            var ln = ' ';

            while ((ln = reader.readLine()) != null) {

                document += ln + "\n";

            }

            return document;

        }