// ==UserScript==
// @name        Interactions
// @namespace   Phcscript
// @include     *oscarRx/choosePatient.do*
// @description Shows drug interactions
// @version     2.2
// @grant       none
// ==/UserScript==

//=====Get Parameters============
var params = {};
if (location.search) {
    var parts = location.search.substring(1).split('&');
    for (var i = 0; i < parts.length; i++) {
        var nv = parts[i].split('=');
        if (!nv[0]) continue;
        params[nv[0]] = nv[1] || true;
    }
}

var URL = window.location.toString()
//alert(URL)

//========Get Path============
var elements = (window.location.pathname.split('/', 2))
firstElement = (elements.slice(1))
//alert(firstElement)
vPath = ("https://" + location.host + "/" + firstElement + "/")
//alert(vPath)

if (URL.indexOf("oscarRx/choosePatient") > -1) {

    //========Buttons============
    var input1 = document.createElement("input");
    input1.type = "button";
    input1.value = "Drug Interactions";
    input1.onclick = ButtonFunction1;
    input1.setAttribute("style", "font-size:12px;position:fixed;top:30px;right:0px;color:white;background-color:#007bff;border-color:#007bff;border-radius: 4px;padding: 3px !important;");
    document.body.appendChild(input1);

    function ButtonFunction1() {
            let alldrugs = assembleRxDrugs();
            console.log("All drugs:"+alldrugs);
            getInteractions(alldrugs);
    }
        function assembleRxDrugs() {
            //iterate through the generic names and assemble the array
            var druglist = []
            var atag = document.getElementsByTagName('a');
            for (var i = 0; i < atag.length; i++) {
                if ((atag[i].innerText.indexOf("Ingredient") > -1) || atag[i].outerHTML.indexOf("query=") > -1) {
                    y = atag[i].innerText.replace(/&nbsp;/g, ' ').trim();
                if (atag[i].innerText.indexOf("Ingredient") > -1) {
                    y = atag[i].innerText.substring(12)
                }
                    y = y.split("/");
                    for (j = 0; j < y.length; j++) {
                        y[j] = y[j].trim();
                        //take the first word or the first word in each word/word combo
                        newwordA = y[j].match(/(?:^|(?:\.\s))(\w+)/);
                        if (newwordA){
                            console.log(newwordA[0]);
                            druglist.push(newwordA[0]);
                        }
                    }
                }
            }
            console.log("Searching the following drugs for interactions:"+druglist)
            return druglist;
        }	
        async function getInteractions(drugs) {
            let drugsStr = drugs.toString().replace(/,/gi,', ');
			if (drugs.length < 1) { alert("You must have some Rx set to perscribe prior to checking"); return; } 
            let alertlist= "<strong>"+ drugsStr +" interactions are:</strong><br>";
            getRxcui(drugs).then(
                async function(rxcuis) {
                const response = await fetch('https://rxnav.nlm.nih.gov/REST/interaction/list?rxcuis='+rxcuis);
                const str = await response.text();
                parser = new DOMParser();
                xmlDoc = parser.parseFromString(str, 'text/xml');
                y = xmlDoc.getElementsByTagName("description").length
                for (x = 0; x < y; x++) {
                    z = (xmlDoc.getElementsByTagName("description")[x].childNodes[0].nodeValue);
                    alertlist = alertlist + "<p>" + z
                }
                if (y <1 ) { alertlist="No interactions found with " + drugsStr +"<p>Use this service with discretion!  This product uses publicly available data from the U.S. National Library of Medicine (NLM), National Institutes of Health, Department of Health and Human Services; NLM is not responsible for the product and does not endorse or recommend this or any other product"; }

                //append
                document.getElementById('interactionsRxMyD').innerHTML += '<div style="background-color:silver;margin-right:100px;margin-left:20px;margin-top:10px;padding-left:10px;padding-top:10px;padding-bottom:5px;border-bottom: 2px solid gray;border-right: 2px solid #999;border-top: 1px solid #CCC;border-left: 1px solid #CCC;width:300px;">' +
alertlist +'<p>source: <a href="https://lhncbc.nlm.nih.gov/RxNav/" target="blank_">RxNav</a> and <a href="https://go.drugbank.com/drug-interaction-checker" target="blank_">Drugbank</a> <span style="font-size:9px;">CC BY-NC 4.0</span></div>'

                }
            )
        }
        async function getRxcui(names) {
            // we have to get RxCUI
            let responses = "";
            for (let name of names){
                const response = await fetch('https://rxnav.nlm.nih.gov/REST/rxcui.json?name='+name);
                const json = await response.json();
                console.log(name+json.idGroup.rxnormId);
                if (json.hasOwnProperty('idGroup')){
                    if (json.idGroup.hasOwnProperty('rxnormId')){
                        responses += json.idGroup.rxnormId ;
                        responses += "+";
                    }
                }
            }
            console.log("Rxcui found:"+responses);
            return responses;
        }
}