function grSelectRows(cb){
   this.config.print(this.fName+": selectRows");
   let xRows=new Object();
   let gObj=this;
   xRows.schemaName=this.schemaName;
   xRows.queryName=this.queryName;
   xRows.success=cb;
   xRows.failure=function(errorInfo){gObj.fail(errorInfo);};
   LABKEY.Query.selectRows(xRows);
   this.config.print(this.fName+": selectRows completed");
}

function grInsertRows(rows){
   this.config.print(this.fName+": insertRows");
   let iRows=new Object();
   let gObj=this;
   iRows.schemaName=this.schemaName;
   iRows.queryName=this.queryName;
   iRows.rows=rows;
   iRows.success=function(data){gObj.callback(data);};
   LABKEY.Query.insertRows(iRows);
}
 
function zeroPad(val,strLength=3){
   let strK=val.toString();
   return strK.padStart(strLength,'0');
}

function findFirstAvailableKey(rows){
   let k=-1;
   for (let i=0;i<rows.length;i++){
      if (rows[i]['Key']>k){
         k=rows[i]['Key'];
      }
   }
   this.config.print(this.fName+': Key candidate: '+(k+1));
   return k+1;
}

function generateObjectAtKey(k){
   let regCode=this.codeBase+this.zeroPad(k);
   this.config.print(this.fName+": regCode "+regCode);
   let row=new Object();
   row['Key']=k;
   row[this.codeField]=regCode;
   if ("addData" in this){
      for (let q in this.addData){
         row[q]=this.addData[q];
      }
   }
   return row;
}

function getCode(row){
   return row[this.codeField];
}

function updateField(text){
   let el=this.config.document.getElementById(this.elementId);
   el.value=text;
}

function generateId(data){
   this.config.print(this.fName+": generateId "+data.rows.length);
   let k=this.findFirstAvailableKey(data.rows);
   let row=this.generateObjectAtKey(k);
   this.updateField(this.getCode(row));
   let rows=new Array();
   rows.push(row);
   this.insertRows(rows);
}

function doNothing1(data){
   this.config.print(this.fName+": doNothing() called");
}

function fail(errorInfo){
   this.config.print(this.fName+": error "+errorInfo.exception);
}

function execute(){
   let gObj=this;
   this.config.print(this.fName+": execute");
   this.selectRows(function(data){gObj.generateId(data);});
}

function inspect(){
   this.config.print(this.fName);
   this.config.print("query: "+this.schemaName+'/'+this.queryName);
   this.config.print("codeBase "+this.codeBase+" codeField "+this.codeField);
   this.config.print("version 25");
}

//generic function for all functors
//config is there by default
//
//pars is semicolon delimeted list of parName=value pairs;
//required:
//codeBase - prepend ids with this set of letters
//schemaName - schema of queryName
//queryName - query that keeps assigned ids
//codeField - id field in queryName
//
//outputId is the field that gets updated with the button result
//
//object is initialized from a list in LabKey
//
function getGenerationObject(config,qPar,outputId){
   let gObj=new Object();
   gObj.config=config;
   gObj.insertRows=grInsertRows;
   gObj.selectRows=grSelectRows;
   gObj.zeroPad=zeroPad;
   gObj.findFirstAvailableKey=findFirstAvailableKey;
   gObj.generateObjectAtKey=generateObjectAtKey;
   gObj.getCode=getCode;
   gObj.updateField=updateField;
   gObj.generateId=generateId;
   gObj.codeBase=qPar["codeBase"];
   gObj.schemaName=qPar["schemaName"];
   gObj.queryName=qPar["queryName"];
   gObj.codeField=qPar["codeField"];
   gObj.elementId=outputId;
   gObj.execute=execute;
   gObj.inspect=inspect;
   gObj.fName="[generateRegistration]";
   gObj.fail=fail;
   gObj.doNothing1=doNothing1;
   gObj.callback=gObj.doNothing1;
   //should set codeBase and elementId after initialization
   return gObj;
}