smarttime/ts/smarttime.classes.cronparser.ts
2022-11-21 09:14:32 +01:00

89 lines
2.6 KiB
TypeScript

import * as plugins from './smarttime.plugins.js';
export class CronParser {
public cronExpression: string;
public get cronArray() {
return this.cronExpression.split(' ');
}
constructor(cronExpressionArg: string) {
this.cronExpression = cronExpressionArg;
if (this.cronArray.length < 6) {
throw new Error('CronParser needs second level accuracy');
}
}
private getNextPartMatch(cronPart: string, startValue: number, moduloArg: number) {
if (cronPart === '*') {
return startValue;
}
if (cronPart.includes('/')) {
const every = parseInt(cronPart.split('/')[1], 10);
const findEvenMatch = (recursionStartArg: number): number => {
if (recursionStartArg % every === 0) {
return recursionStartArg;
} else {
return findEvenMatch(recursionStartArg + 1);
}
};
return findEvenMatch(startValue);
}
if (parseInt(cronPart, 10) || cronPart === '0') {
const match = parseInt(cronPart, 10);
return match;
}
}
public msToNext() {
const cronArray = this.cronArray;
const secondExpression = cronArray[0];
const minuteExpression = cronArray[1];
const hourExpression = cronArray[2];
const dayExpression = cronArray[3];
const monthExpression = cronArray[4];
const yearExpression = cronArray[5];
let currentDate = new Date();
let currentSecond = currentDate.getSeconds() + 1;
let currentMinute = currentDate.getMinutes();
let currentHour = currentDate.getHours();
let currentDay = currentDate.getDate();
let currentMonth = currentDate.getMonth();
let currentYear = currentDate.getFullYear();
const targetSecond = this.getNextPartMatch(secondExpression, currentSecond, 59);
if (targetSecond < currentSecond) {
currentMinute = (currentMinute + 1) % 59;
}
const targetMinute = this.getNextPartMatch(minuteExpression, currentMinute, 59);
if (targetMinute < currentMinute) {
currentHour = (currentHour + 1) % 23;
}
const targetHour = this.getNextPartMatch(hourExpression, currentHour, 23);
if (targetHour < currentHour) {
currentDay = (currentDay + 1) % 30;
}
const targetDay = currentDay;
if (targetDay < currentDay) {
currentMonth = (currentMonth + 1) % 11;
}
const targetMonth = currentMonth;
if (targetMonth < currentMonth) {
currentYear = currentYear + 1;
}
const targetYear = currentYear;
const targetDate = new Date(
targetYear,
targetMonth,
targetDay,
targetHour,
targetMinute,
targetSecond
);
const targetTime = targetDate.getTime();
return targetTime - Date.now();
}
}