/* Check age and category entered on registration form against the age category requirements
 * Script requires two elements from the form; one with an id that contains'yearBorn',
 * and one with a name that contains 'Category'. Both inputs must be assigned a class of 'target'.
 *
 * eventYear is exposed in the document by customization to the php code,
 * the customization must be added to components\com_eventbooking\view\register\html.php after
 * '$event = EventbookingHelperDatabase::getEvent($eventId);' around line 34
 * OR to components\com_eventbooking\view\override\register\html.php to void overwrite on upgrade
*
/* Customization to add javascript variable store event year
 *	 $eventYear = JHtml::_('date', $event->event_date, 'Y', null);
 * 	 $document = JFactory::getDocument();
 *	 $document->addScriptDeclaration('
 *	     const eventYear = $eventYear;
 *	   ');
 **************************************************************************************************************************************
*/

Ready();

function Ready() {  //add listener on document when document ready
  if (document.readyState !== 'loading'){
    FormListener();
  } else {
    document.addEventListener('DOMContentLoaded', FormListener);
  }
}

function FormListener() { //set event listener on form member information parent as form elements for individuals in group registration are created after page load; event will bubble up to parent
  document.getElementById("t3-content").addEventListener("focusout", DetectChildFocusOut);
  //prevent event bubbling
  event.stopPropagation();
}
		
function DetectChildFocusOut() {		//check for desired event trigger element by checking for class
		if (event.target.classList.contains('target')) {
            CategoryAgeValidate();
		};
} //end DetectChildFocusOut	
  
function CategoryAgeValidate() {
  let categoryElementId = "";
  let yearBornElementId = "";
  const targetId = event.target.id;
  const birthYearEnteredElementName = "yearBorn"

  IdElements();
  ValidateAge();
 
    function IdElements() {
    //get name and sequence number of target
    let sequenceNumber = targetId.match(/\d+$/);	//identifies individual in group registration
    const categoryName = document.querySelector('[id^="Category_"]').id.match(/[a-zA-Z_]+/).toString();

    if (sequenceNumber){
      sequenceNumber = sequenceNumber.toString();
    }  
    //determine element pair to test
    if(sequenceNumber) {	//is this a group member
      if(targetId.includes(birthYearEnteredElementName)){
        yearBornElementId = targetId;
        categoryElementId = `${categoryName}${sequenceNumber}`;
      } else {
        yearBornElementId = `${birthYearEnteredElementName}_${sequenceNumber}`;
        categoryElementId = targetId;
      }
    } else {	//individual registration
      yearBornElementId = birthYearEnteredElementName;
      categoryElementId = categoryName;
    }
    return[yearBornElementId, categoryElementId]
  } //end IdElements

  function ValidateAge(elementIds) { 
    //get input values from form
    const birthYearEntered = Number(document.getElementById(yearBornElementId).value);
    const categorySelected = document.getElementById(categoryElementId).value;
 
    //return if input empty
    if (!birthYearEntered || !categorySelected) {
      return;
    }
    //determine refernce values for category selected in form
    const categoryParms = CategoryCheck(categorySelected);
    //test form inputs against reference values
    const testResult = TestAge(birthYearEntered, categoryParms);

    if (testResult !== 4) { //validation failed, notify user
      ValidationResultDisplay(testResult, categorySelected, categoryElementId);
    }
  } //end ValidateAge

  function CategoryCheck(categorySelected) {  //get parameters for selected category 
    // clean up category name input from form
    if (categorySelected.slice(-1) === '+') { //replace + at end of Master categories
      categorySelected = categorySelected.slice(0, -1);
    }

    if (categorySelected.includes('/')) { //replace / used in some categories
      categorySelected = categorySelected.replace(/\//g, '_');
    }

    if (categorySelected.includes(' ')) { //replace space used in some categories
      categorySelected = categorySelected.replace(/\s/g, '_');
    }
    //category references
    const categories = [
      {name: "Master80", floor: 80, ceiling: 89},
      {name: "Master70", floor: 70, ceiling: 79},
      {name: "Master60", floor: 60, ceiling: 69},
      {name: "Master50", floor: 50, ceiling: 59},
      {name: "Senior", floor: 21, ceiling: 49},
      {name: "Junior", floor: 18, ceiling: 20},
      {name: "Cadet", floor: 15, ceiling: 17},
      {name: "Cub", floor: 13, ceiling: 14},
      {name: "Bowman", floor: 10, ceiling: 12},
      {name: "Yeoman", floor: 7, ceiling: 9},
      {name: "Collegiate", floor: 17, ceiling: 49},
      {name: "ExecFITA", floor: 21, ceiling: 89},
      {name: "ParaW1", floor: 10, ceiling: 89},
      {name: "ParaOpen", floor: 10, ceiling: 89},
      {name: "ParaVI1", floor: 10, ceiling: 89},
      {name: "ParaVI2_VI3", floor: 10, ceiling: 89},
      {name: "ParaVI2_3", floor: 10, ceiling: 89}
    ];
    //select reference category based on form input
    const categoryRef = categories.filter(category => category.name === categorySelected);
    return categoryRef;
  } //end CategoryCheck

  function TestAge(birthYearEntered, categoryParms) { //test inputs against category parameters
    // universal control parameters for category/age test
    const lowerlimit = 8; //lowest age that can register without official intervention
    const upperlimit = 90;  //highest age that can register without official intervention
    const senior = 21; // sets lower limit that Master age group can register, i.e., senior
    const master = 50;  //set age for category direction split, those below and above split have opposing hierarchies

    // parameters that inputs will test against
    let categoryRefName = categoryParms[0].name;
    let categoryRefFloor = categoryParms[0].floor;
    let categoryRefCeiling = categoryParms[0].ceiling;

    // parameters
    let age = eventYear - birthYearEntered;
    let testResultFlag = 4; //default test result flag

    // Test Flags - 0:test failed; 1:age ineligible for category; 2:age eligible for lower category; 3:require intervention; 4:OK

    if (age < lowerlimit || age >= upperlimit) {   // screen out questionable ages
          testResultFlag = 3;
      } else if (age >= master) {
          // Master categories are in age descending order, i.e., higher age is lower category
          if (categoryRefFloor > age || categoryRefCeiling < senior) {
            testResultFlag = 1;
          } else if (categoryRefFloor >= senior && categoryRefCeiling < age) {
            testResultFlag = 2;
          }
      } else if (age < master) {
          // Categories are in age ascending order
          if (categoryRefFloor > age && categoryRefFloor < master && categoryRefName !== 'Collegiate') {
              testResultFlag = 2;
          } else if (categoryRefFloor >= master || categoryRefCeiling < age) {
              testResultFlag = 1;
          }
      } else {
          testResultFlag = 0;
    }
    //return test results
    return [testResultFlag, age];
  } // end testAge()

  function ValidationResultDisplay(testResult, categorySelected, categoryElementId) {
    const resultFlag = testResult[0];
    const archerAge = testResult[1];
    const msg = new Array(4); //set up messages
    //setup alert messages
    msg[0]= "ERROR:  \n An error has occurred; please contact the website administrator.";
    msg[1] = "VIOLATION: \n Archer is " + archerAge + " years old for " + eventYear + " competitions (based on their age as of December 31 " + eventYear + ") and not eligible for the " + categorySelected + " category. Please select another category";
    msg[2] = "ADVISORY:  \n Archer is " + archerAge + " years old for " + eventYear + " competitions and registering in a higher category than required by their age. If you register in the selected " + categorySelected + " category the archer will be 'shooting up'.";
    msg[3]= "INTERVENTION REQUIRED:  \n Archer is " + archerAge + " years old. Please contact the tournament director for registration.";

    //select appropriate message
    if (resultFlag === 0) { //test failed
      alert(msg[0]);
      ClrCategory(categoryElementId); //reset category input on form
    } else if (resultFlag === 1) { //too old
      alert(msg[1]);
      ClrCategory(categoryElementId); //reset category input on form
    } else if (resultFlag === 2) { //shooting up
      alert(msg[2]);
    } else if (resultFlag === 3) { //unreasonable age
      alert(msg[3]);
      ClrCategory(categoryElementId); //reset category input on form
    } //end if

    //reset category form element if age not eligible for selected category
    function ClrCategory(categoryElementId) {
    document.getElementById(categoryElementId).value=""; //reset category input on form).val('');
    } //end clrCategory
    return;
  } //end ValidationResultDisplay
} //end CategoryAgeValidate