import { getCourseParticipantsUrl } from "./config.js";
import { fetchStudents } from "./student-ENV.js";

/**
 * Class to represent a Group of Students.
 */
class Group {
	constructor(name, students) {
		this.name = name;
		if (!students) {
			this.students = [];
		}
	}

	setStudents(students) {
		this.students = students;
	}

	addStudent(student) {
		this.students.push(student);
	}

	async getStudents() {
		return students;
	}
}

let groups = new Map();

function buildGroups(students) {
	for (const student of students) {
		for (const groupName of student.groups) {
			if (!groups.has(groupName)) {
				groups.set(groupName, new Group(groupName));
			}
			groups.get(groupName).addStudent(student);

			// Create the individual student group
			const sGroupName = student.getGroupName();
			groups.set(sGroupName, new Group(sGroupName, [student]));
		}
	}
}

/**
 * Fetch all Groups and return them as a map.
 */
async function fetchGroups() {
	if (groups.size) {
		return groups;
	}

	// Fetch all students and build the groups from them
	const students = fetchStudents();
	buildGroups(students);
	return groups;
}

export { Group, buildGroups, fetchGroups };