Hangaram High School timetable processor

processor.js

function downloadTimetable(timetableElement) {
    const timetable = makeTimetable(timetableElement);
    download(timetable[0], 'timetable1.json');
    download(timetable[1], 'timetable2.json');
    download(timetable[2], 'timetable3.json');
}

function download(o, fileName) {
    const blob = new Blob([JSON.stringify(o)], {type: 'application/json'});
    const url = URL.createObjectURL(blob);

    const a = document.createElement('a');
    a.href = url;
    a.download = fileName;
    document.body.appendChild(a);
    a.click();
    a.remove();

    URL.revokeObjectURL(url);
}

function makeTimetable(timetableElement) {
    return processGrid(makeGrid(timetableElement));
}

function makeGrid(timetableElement) {
    const result = [];
    for (let i = 0; i < timetableElement.rows.length; i++) {
        result[i] = [];
    }

    for(let i = 0; i < timetableElement.rows.length; i++) {
        const row = timetableElement.rows[i];
        let j = 0;
        while (typeof result[i][j] !== 'undefined') {
            j++;
        }
        for (let cell of row.children) {
            let colspan = parseInt(cell.getAttribute('colspan'), 10);
            if (Number.isNaN(colspan)) {
                colspan = 1;
            }
            let rowspan = parseInt(cell.getAttribute('rowspan'), 10);
            if (Number.isNaN(rowspan)) {
                rowspan = 1;
            }
            for (let i2 = 0; i2 < rowspan; i2++) {
                for (let j2 = 0; j2 < colspan; j2++) {
                    result[i + i2][j + j2] = cell.textContent;
                }
            }
            j += colspan;
            while (typeof result[i][j] !== 'undefined') {
                j++;
            }
        }
    }
    return result;
}

function processGrid(grid) {
    const result = [];
    for (let grade = 1; grade <= 3; grade++) {
        const gradeResult = [];
        for (let lectureClass = 1; lectureClass <= 8; lectureClass++) {
            const lectureClassResult = [];
            for (let dayOfTheWeek = 1; dayOfTheWeek <= 5; dayOfTheWeek++) {
                const dayOfTheWeekResult = [];
                for (let period = 1; period <= 6; period++) {
                    dayOfTheWeekResult[period - 1] = toClassArray(getClassString(grid, grade, lectureClass, dayOfTheWeek, period));
                }
                lectureClassResult[dayOfTheWeek - 1] = dayOfTheWeekResult;
            }
            gradeResult[lectureClass - 1] = lectureClassResult;
        }
        result[grade - 1] = gradeResult;
    }
    return result;
}

function getClassString(grid, grade, lectureClass, dayOfTheWeek, period) {
    if (dayOfTheWeek === 5 && period === 6) {
        period = 5;
    }
    return grid[2 + (dayOfTheWeek - 1) * 6 + (period - 1)][2 + (grade - 1) * 8 + (lectureClass - 1)];
}

function toClassArray(classString) {
    if (classString === '') {
        return [];
    }
    if (classString === '자율(자치, 보건) 봉사') {
        return [{
            'subject': '자율(자치, 보건) 봉사',
            'teacher': '담임'
        }];
    }
    if (classString === '동아리/행사') {
        return [{
            'subject': '동아리/행사',
            'teacher': '담임'
        }];
    }
    const result = classString.split(/\/(?![^()]*(?:\([^()]*\))?\))/);
    if (result.length === 2 && result[1].startsWith('B')) {
        result[1] = result[0].split('A')[0] + result[1];
    }
    return result.map(e => {
        const split = e.split('(');
        return {
            'subject': split[0],
            'teacher': split[1].split(')')[0]
        }
    });
}