utils.ts•6.94 kB
/**
* Utility functions for Google Calendar MCP server
* Handles date/time parsing, formatting, and natural language processing
*/
// Regular expression to check if a string is in ISO format
const ISO_DATE_REGEX = /^\d{4}-\d{2}-\d{2}(T\d{2}:\d{2}(:\d{2})?)?$/;
/**
* Parse date and time from various formats including natural language
* @param dateTimeString Date/time string in ISO format or natural language
* @param referenceDate Optional reference date for relative times
* @returns Date object
*/
export function parseDateTime(dateTimeString: string, referenceDate?: Date): Date {
// If already in ISO format, parse directly
if (ISO_DATE_REGEX.test(dateTimeString)) {
return new Date(dateTimeString);
}
// Set default reference date to now if not provided
const reference = referenceDate || new Date();
const lowerString = dateTimeString.toLowerCase().trim();
// Handle common natural language patterns
if (lowerString === 'now' || lowerString === 'today') {
return new Date();
}
if (lowerString === 'tomorrow') {
const tomorrow = new Date(reference);
tomorrow.setDate(tomorrow.getDate() + 1);
tomorrow.setHours(9, 0, 0, 0); // Default to 9 AM
return tomorrow;
}
// Handle "X hours later" pattern
const hoursLaterMatch = lowerString.match(/(\d+)\s*hours?\s*later/i);
if (hoursLaterMatch) {
const hoursToAdd = parseInt(hoursLaterMatch[1], 10);
const result = new Date(reference);
result.setHours(result.getHours() + hoursToAdd);
return result;
}
// Handle "X days later" pattern
const daysLaterMatch = lowerString.match(/(\d+)\s*days?\s*later/i);
if (daysLaterMatch) {
const daysToAdd = parseInt(daysLaterMatch[1], 10);
const result = new Date(reference);
result.setDate(result.getDate() + daysToAdd);
return result;
}
// Handle "next week" pattern
if (lowerString === 'next week') {
const nextWeek = new Date(reference);
nextWeek.setDate(nextWeek.getDate() + 7);
nextWeek.setHours(9, 0, 0, 0); // Default to 9 AM
return nextWeek;
}
// Handle days of week (e.g., "next monday")
const dayOfWeekMatch = lowerString.match(/next\s*(monday|tuesday|wednesday|thursday|friday|saturday|sunday)/i);
if (dayOfWeekMatch) {
const dayOfWeek = ['sunday', 'monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday']
.indexOf(dayOfWeekMatch[1].toLowerCase());
const result = new Date(reference);
const currentDay = result.getDay();
// Calculate days to add to get to the specified day
let daysToAdd = dayOfWeek - currentDay;
if (daysToAdd <= 0) daysToAdd += 7; // Ensure we're moving to "next" week if needed
result.setDate(result.getDate() + daysToAdd);
result.setHours(9, 0, 0, 0); // Default to 9 AM
return result;
}
// Handle specific times on relative dates (e.g., "tomorrow at 3pm")
const dateTimeMatch = lowerString.match(/(today|tomorrow|monday|tuesday|wednesday|thursday|friday|saturday|sunday)\s+at\s+(\d+)(?::(\d+))?\s*(am|pm)?/i);
if (dateTimeMatch) {
// Parse the date part
let dateResult: Date;
const datePart = dateTimeMatch[1].toLowerCase();
if (datePart === 'today') {
dateResult = new Date(reference);
} else if (datePart === 'tomorrow') {
dateResult = new Date(reference);
dateResult.setDate(dateResult.getDate() + 1);
} else {
// Handle day of week
const dayOfWeek = ['sunday', 'monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday']
.indexOf(datePart);
dateResult = new Date(reference);
const currentDay = dateResult.getDay();
// Calculate days to add to get to the specified day
let daysToAdd = dayOfWeek - currentDay;
if (daysToAdd <= 0) daysToAdd += 7; // Move to next week
dateResult.setDate(dateResult.getDate() + daysToAdd);
}
// Parse the time part
let hour = parseInt(dateTimeMatch[2], 10);
const minute = dateTimeMatch[3] ? parseInt(dateTimeMatch[3], 10) : 0;
const isPM = dateTimeMatch[4]?.toLowerCase() === 'pm';
// Adjust hour for PM if needed
if (isPM && hour < 12) hour += 12;
if (!isPM && hour === 12) hour = 0; // 12 AM is 00:00
dateResult.setHours(hour, minute, 0, 0);
return dateResult;
}
// Try using the built-in Date parser as a fallback
const date = new Date(dateTimeString);
if (!isNaN(date.getTime())) {
return date;
}
// If all parsing attempts fail, throw an error
throw new Error(`Unable to parse date/time: ${dateTimeString}`);
}
/**
* Format a date/time object or Google Calendar datetime object for display
* @param dateTimeObj Date object or Google Calendar dateTime object
* @returns Formatted date/time string
*/
export function formatDateTime(dateTimeObj: any): string {
if (!dateTimeObj) return 'Not specified';
// Handle Google Calendar API's date/dateTime format
if (typeof dateTimeObj === 'object' && (dateTimeObj.dateTime || dateTimeObj.date)) {
// For all-day events, use date format
if (dateTimeObj.date) {
const date = new Date(dateTimeObj.date + 'T00:00:00');
return date.toLocaleDateString(undefined, {
weekday: 'long',
year: 'numeric',
month: 'long',
day: 'numeric'
}) + ' (All day)';
}
// For regular events with specific times
const date = new Date(dateTimeObj.dateTime);
return date.toLocaleString(undefined, {
weekday: 'long',
year: 'numeric',
month: 'long',
day: 'numeric',
hour: 'numeric',
minute: '2-digit',
timeZoneName: 'short'
});
}
// Handle JavaScript Date objects
if (dateTimeObj instanceof Date) {
return dateTimeObj.toLocaleString(undefined, {
weekday: 'long',
year: 'numeric',
month: 'long',
day: 'numeric',
hour: 'numeric',
minute: '2-digit',
timeZoneName: 'short'
});
}
// Handle ISO strings
if (typeof dateTimeObj === 'string') {
return new Date(dateTimeObj).toLocaleString(undefined, {
weekday: 'long',
year: 'numeric',
month: 'long',
day: 'numeric',
hour: 'numeric',
minute: '2-digit',
timeZoneName: 'short'
});
}
// Default fallback
return String(dateTimeObj);
}