Recurring Events

							
							/* Base specific  */
const table = base.getTable('Events');

function assignDate(existingRecord, date) {
    return {fields: {
        Name: existingRecord.getCellValue('Name'),
        Date: date,
        Notes: existingRecord.getCellValue('Notes'),
    }};
}

/* And this is just the working bit */
const daysOfWeek = [
    {label: 'Sunday', value: '0'},
    {label: 'Monday', value: '1'},
    {label: 'Tuesday', value: '2'},
    {label: 'Wednesday', value: '3'},
    {label: 'Thursday', value: '4'},
    {label: 'Friday', value: '5'},
    {label: 'Saturday', value: '6'},
];

const months = [
    {label: 'January', value: '0'},
    {label: 'February', value: '1'},
    {label: 'March', value: '2'},
    {label: 'April', value: '3'},
    {label: 'May', value: '4'},
    {label: 'June', value: '5'},
    {label: 'July', value: '6'},
    {label: 'August', value: '7'},
    {label: 'September', value: '8'},
    {label: 'October', value: '9'},
    {label: 'November', value: '10'},
    {label: 'December', value: '11'},
];

const freq = [];
for (let i = 1; i <= 50; i++) {
    freq.push(i.toString());
}


output.markdown(`# ? Let's make some recurring events!`);
const record = await input.recordAsync('Select Event', table);

let eventDate = record.getCellValue('Date');
output.clear();
output.markdown(`## ? You selected '**${record.name}**'`);

const repeatFreq = await input.buttonsAsync(`How frequently does ${record.name} occur?`, ['Daily', 'Weekly', 'Monthly',]);
const newRecords = [];

switch (repeatFreq) {
    case 'Weekly': {
        const repeatDay = await input.buttonsAsync('Repeats every...', daysOfWeek);
        const repeatWeeks = await input.buttonsAsync('for X weeks.', freq);
        const niceDay = dayOfWeekNumberToString(repeatDay);

        output.clear();
        output.markdown(`# ? We will make '**${record.name}**' an event every **${niceDay}** for **${repeatWeeks}** weeks. On these dates:`);

        /* Add events to newRecords array */
        eventDate = shiftDay(eventDate, parseInt(repeatDay, 10));

        for (let i = 1; i <= parseInt(repeatWeeks, 10); i++) {
            const newDate = addDays(eventDate, (7 * i));
            newRecords.push(assignDate(record, newDate));
            output.text(newDate.toLocaleString());
        }
        break;
    }
    case 'Daily': {
        const repeatWeeks = await input.buttonsAsync('For how many days?', freq);

        output.clear();
        output.markdown(`# ? We will make '**${record.name}**' an event every day. On these dates:`);

        /* Add events to newRecords array */
        for (let i = 1; i <= parseInt(repeatWeeks, 10); i++) {
            const newDate = addDays(eventDate, i);
            newRecords.push(assignDate(record, newDate));
            output.text(newDate.toLocaleString());
        }
        break;
    }
    case 'Monthly': {
        const repeatTiming = await input.buttonsAsync('Which week of the month?', ['First', 'Second', 'Third', 'Last']);
        const repeatDay = await input.buttonsAsync(`on the ${repeatTiming}...`, daysOfWeek);
        const repeatStartMonth = await input.buttonsAsync('Starting in...', months);
        
        const repeatWeeks = await input.buttonsAsync('For how many months?.', freq);
        const niceDay = dayOfWeekNumberToString(repeatDay);
        output.clear();
        eventDate = shiftYear(eventDate,parseInt(repeatStartMonth, 10));
        output.markdown(`# ? We will make '**${record.name}**' an event every **${niceDay}** for **${repeatWeeks}** months starting **${eventDate.toLocaleString()}**. On these dates:`);
        
        /* Add events to newRecords array */
        const r = parseInt(repeatWeeks, 10);
        const m = parseInt(repeatStartMonth, 10);

        for (let i = 0; i < r; i++) {
            const newDate = shiftMonthly(eventDate, (m + i), parseInt(repeatDay, 10), repeatTiming);
            newRecords.push(assignDate(record, newDate));
            output.text(newDate.toLocaleString());
        }
        break;
    }
    default:
        throw new Error('Unrecognized repeat frequency');
}

/* Confirm before creating records */
const creationConfirmation = await input.buttonsAsync('Is that right?', [{label: '?‍♀️ Cancel', value: 'stop'}, {label: '?DO IT! Create those EVENTS!', value: 'go', variant: 'danger'}]);
output.clear();
switch (creationConfirmation) {
    case 'stop': {
        output.markdown("# ? We won't make a repeating event.");
        break;
    }
    case 'go': {
        await table.createRecordsAsync(newRecords);
        output.markdown(`# ? Check out your new events in '${table.name}'!`);
        break;
    }
    default:
        throw new Error('Unknown selection');
}

/* Functions */
function dayOfWeekNumberToString(v) {
    const result = daysOfWeek.find(day => day.value === v);
    return result.label;
}

function addDays(date, days) {
    const result = new Date(date);
    result.setDate(result.getDate() + days);
    return result;
}

function shiftDay(date, newDay) {
    const d = new Date(date);
    const day = d.getDay();
    const dif = newDay - day;
    return addDays(date, dif);
}

function shiftYear(date, month) {
    let result = new Date(date);
    if((month - result.getMonth()) < 0 ){
        result.setFullYear(result.getFullYear() + 1);
    } 
    return result;
}

function shiftMonthly(date, month, dy, timing) {
    let result = new Date(date);
    let modifier = 0;
    result.setDate(1);
    result.setMonth(month);
    switch (timing) {
        case 'First':
            break;
        case 'Second':
            modifier = 7;
            break;
        case 'Third':
            modifier = 14;
            break;
        case 'Last':
            modifier = -7;
            result.setMonth(month + 1);
            break;
        default:
            throw new Error('Unexpected timing');
    }
    let firstday = result.getDay() === dy;
    while (firstday === false) {
        result = addDays(result, 1);
        firstday = result.getDay() === dy;
    }
    return addDays(result, modifier);
}