now

// Students graduation

/**
 *
 * @param {{ course: string, passingGrade: number, students: Array<{id: number, name: string}>, grades: Array<{ studentId: number, grade: number}>, exams: Array<{ studentId: number, grade: number }>} data
 */
export default function (data) {
  const students = data.students.map((student) => {

    const grades = data.grades
      .filter((x) => {
        if (x.studentId === student.id || x.studentName === student.name)

        return x.grade;
      })
      .map((x) => {

        return x.grade;
      });

    const avgGradeGrades =
      (grades.reduce((acc, el) => acc + el, 0) / grades.length) * 0.4;

    const examGrades = data.exams
      .filter((x) => {
        if (x.studentId === student.id || x.studentName === student.name)

        return x.grade;
      })
      .map((x) => {

        return x.grade;
      });

    const avgGradeExam =
      examGrades.length === 0 ? 0 : (examGrades.reduce((acc, el) => acc + el, 0) / examGrades.length) * 0.6;

    const finalGrade = avgGradeGrades + avgGradeExam;

    return { ...student, grade: finalGrade, attendsToExam: examGrades.length };
  });

  return {
    name: data.course,

    graduates: students.reduce((acc, el) => {
      if (el.grade >= data.passingGrade && el.attendsToExam >= 2) {
        acc.push({ id: el.id, name: el.name, grade: el.grade });
      }

      return acc;
    }, []),

    nonGraduates: students.reduce((acc, el) => {
      if (el.grade < data.passingGrade && el.attendsToExam < 2) {
        acc.push({ id: el.id, name: el.name, reason: "score and exams" });
      } else if (el.grade < data.passingGrade && el.attendsToExam >= 2) {
        acc.push({ id: el.id, name: el.name, reason: "score" });
      } else if (el.grade >= data.passingGrade && el.attendsToExam < 2) {
        acc.push({ id: el.id, name: el.name, reason: "exams" });
      }

      return acc;
    }, []),
  };
}