03. School Register (Objects and Classes)

function solve(input){

    class Student{
        constructor(name, grade, score){
            this.name = name;
            this.grade = grade;
            this.score = score;
        }

        nextGrade(){
            this.grade += 1;
        }
}

class schoolClass{
    constructor(grade){
        this.grade = grade;
        this.students = [];
        this.grades = [];
    }

    addStudent(name, grades){
        this.students.push(name);
        this.grades.push(grades);
    }
    listOfStudents(){
        return this.students.join(', ');
    }

    averageScore(){
        if(this.grades.length > 0){
            let divident = this.grades.reduce((a,b)=>{
                return a+b;
            });
            let divisor = this.grades.length;
            let average = divident / divisor
            return average.toFixed(2);
        }
    }
}

let register = [];
let classes = [];
    for (const record of input) {
        let [first, second, third] = record.split(', ');
        let name = first.split(': ')[1];
        let grade = Number(second.split(': ')[1]);
        let score = Number(third.split(': ')[1]);
        let student = new Student(name, grade, score);
        if( student.score>=3 ){
            student.nextGrade();
        }
        register.push(student);
        classes.push(student.grade);
    }


    let classList = new Set(classes);
    let listOfClasses = [];
    for (const singleClass of Array.from(classList)) {
        let newClass = new schoolClass(singleClass);
            listOfClasses.push(newClass);
    }
listOfClasses.sort((a,b)=>{
    return a.grade - b.grade;
})

for (const one of listOfClasses) {
    for (const student of register) {
        if(one.grade === student.grade){
            if(student.score >= 3){
                one.addStudent(student.name,student.score);
            }

        }
    }
}


    for (const single of listOfClasses) {
        if(single.students.length > 0){
            console.log(`${single.grade} Grade`);
            console.log(`List of students: ${single.listOfStudents()}`);
            console.log(`Average annual grade from last year: ${Number(single.averageScore()).toFixed(2)}`);
            console.log('');
        }

    }


}