I have been asked to figure out what i think this JavaScript function does, but I’m not too sure. I have a general gist of it, I think it is splitting up some input and putting them into an array and returning them in a certain format. But I cannot describe exactly what it does. Can anybody help?

get_facet_query = function(facets) { var filter_query = ""; var requestedFacets = [];  if (facets instanceof Array) {     facets.forEach(function (f) {          var facetStringArray = f.split(",");          facetStringArray.forEach(function (fsa) {             var fsa_pair = fsa.split(":");             var fsa_name = fsa_pair[0].trim().toLowerCase();             var fsa_values = [];             var facetValueStringArray = fsa_pair[1].split("|");             facetValueStringArray.forEach(function (fv) {                 if (fv !== "") fv = fv.toLowerCase();                 fsa_values.push(fv);             });             var x = {                 "name": fsa_name,                 "values": fsa_values             };             requestedFacets.push(x);         });     }); } else {     var facetStringArray = facets.split(",");      facetStringArray.forEach(function (fsa) {         var fsa_pair = fsa.split(":");         if (fsa_pair.length == 2) {             var fsa_name = fsa_pair[0].trim().toLowerCase();             var fsa_values = [];             var facetValueStringArray = fsa_pair[1].split("|");             facetValueStringArray.forEach(function (fv) {                 if (fv !== "") fv = fv.toLowerCase();                 fsa_values.push(fv);             });             var x = {                 "name": fsa_name,                 "values": fsa_values             };             requestedFacets.push(x);         }     }); }  var sqlstring = require('sqlstring');  requestedFacets.forEach(function (f) {     safefname = sqlstring.escape(f.name);     f.values.forEach(function (fv) {         safefv = sqlstring.escape(fv);         filter_query += ' AND LOWER(t.metadata) REGEXP \'"' + safefname.slice(1, safefname.length - 1) + '"(\ )?:(\ )?"[^"]*' + safefv.slice(1,safefv.length - 1) + '[^"]*"\' ';     }); });  return filter_query; 

};