06_deep_foundations_module_pattern_resolved.js

var deepJS = defineWorkshop();

deepJS.addStudent(311,"Frank",/*paid=*/true);
deepJS.addStudent(410,"Suzy",/*paid=*/true);
deepJS.addStudent(709,"Brian",/*paid=*/false);
deepJS.addStudent(105,"Henry",/*paid=*/false);
deepJS.addStudent(502,"Mary",/*paid=*/true);
deepJS.addStudent(664,"Bob",/*paid=*/false);
deepJS.addStudent(250,"Peter",/*paid=*/true);
deepJS.addStudent(375,"Sarah",/*paid=*/true);
deepJS.addStudent(867,"Greg",/*paid=*/false);

deepJS.enrollStudent(410);
deepJS.enrollStudent(105);
deepJS.enrollStudent(664);
deepJS.enrollStudent(375);

deepJS.printCurrentEnrollment();
console.log("----");
deepJS.enrollPaidStudents();
console.log("----");
deepJS.remindUnpaidStudents();

/*
	Bob (664): Not Paid
	Henry (105): Not Paid
	Sarah (375): Paid
	Suzy (410): Paid
	----
	Bob (664): Not Paid
	Frank (313): Paid
	Henry (105): Not Paid
	Mary (502): Paid
	Peter (250): Paid
	Sarah (375): Paid
	Suzy (410): Paid
	----
	Bob (664): Not Paid
	Henry (105): Not Paid
*/


// ********************************

function defineWorkshop() {
	var currentEnrollment = [];
	var studentRecords = [];

	var publicAPI = {
		addStudent,
		enrollStudent,
		printCurrentEnrollment,
		enrollPaidStudents,
		remindUnpaidStudents,
	};
	return publicAPI;


	// ********************************

	function addStudent(id,name,paid) {
		studentRecords.push({ id, name, paid, });
	}

	function enrollStudent(id) {
		if (!currentEnrollment.includes(id)) {
			currentEnrollment.push(id);
		}
	}

	function printCurrentEnrollment() {
		printRecords(currentEnrollment);
	}

	function enrollPaidStudents() {
		currentEnrollment = paidStudentsToEnroll();
		printCurrentEnrollment();
	}

	function remindUnpaidStudents() {
		remindUnpaid(currentEnrollment);
	}

	function getStudentFromId(studentId) {
		return studentRecords.find(matchId);

		// *************************

		function matchId(record) {
			return (record.id == studentId);
		}
	}

	function printRecords(recordIds) {
		var records = recordIds.map(getStudentFromId);

		records.sort(sortByNameAsc);

		records.forEach(printRecord);
	}

	function sortByNameAsc(record1,record2){
		if (record1.name < record2.name) return -1;
		else if (record1.name > record2.name) return 1;
		else return 0;
	}

	function printRecord(record) {
		console.log(`${record.name} (${record.id}): ${record.paid ? "Paid" : "Not Paid"}`);
	}

	function paidStudentsToEnroll() {
		var recordsToEnroll = studentRecords.filter(needToEnroll);

		var idsToEnroll = recordsToEnroll.map(getStudentId);

		return [ ...currentEnrollment, ...idsToEnroll ];
	}

	function needToEnroll(record) {
		return (record.paid && !currentEnrollment.includes(record.id));
	}

	function getStudentId(record) {
		return record.id;
	}

	function remindUnpaid(recordIds) {
		var unpaidIds = recordIds.filter(notYetPaid);

		printRecords(unpaidIds);
	}

	function notYetPaid(studentId) {
		var record = getStudentFromId(studentId);
		return !record.paid;
	}
}