Timesheet Assistant MCP

import { google, calendar_v3 } from 'googleapis'; import { OAuth2Client } from 'google-auth-library'; import { CalendarEvent } from '../types/index.js'; export class GoogleCalendarIntegration { private oauth2Client: OAuth2Client | null = null; private calendar: calendar_v3.Calendar | null = null; private onTokenRefresh?: (tokens: { access_token: string; refresh_token: string; expiry_date: number }) => Promise<void>; async initialize( clientId: string, clientSecret: string, redirectUri: string, tokens?: { access_token: string; refresh_token: string; expiry_date: number }, onTokenRefresh?: (tokens: { access_token: string; refresh_token: string; expiry_date: number }) => Promise<void> ): Promise<void> { this.oauth2Client = new google.auth.OAuth2(clientId, clientSecret, redirectUri); this.onTokenRefresh = onTokenRefresh; if (tokens) { this.oauth2Client.setCredentials(tokens); } this.calendar = google.calendar({ version: 'v3', auth: this.oauth2Client }); } getAuthUrl(): string { if (!this.oauth2Client) { throw new Error('OAuth2 client not initialized'); } return this.oauth2Client.generateAuthUrl({ access_type: 'offline', scope: ['https://www.googleapis.com/auth/calendar.readonly'], prompt: 'consent', }); } async setAuthorizationCode(code: string): Promise<{ access_token: string; refresh_token: string; expiry_date: number; }> { if (!this.oauth2Client) { throw new Error('OAuth2 client not initialized'); } const { tokens } = await this.oauth2Client.getToken(code); this.oauth2Client.setCredentials(tokens); if (!tokens.access_token || !tokens.refresh_token || !tokens.expiry_date) { throw new Error('Invalid tokens received'); } return { access_token: tokens.access_token, refresh_token: tokens.refresh_token, expiry_date: tokens.expiry_date, }; } async refreshAccessToken(): Promise<{ access_token: string; refresh_token: string; expiry_date: number; }> { if (!this.oauth2Client) { throw new Error('OAuth2 client not initialized'); } const { credentials } = await this.oauth2Client.refreshAccessToken(); if (!credentials.access_token || !credentials.refresh_token || !credentials.expiry_date) { throw new Error('Failed to refresh tokens'); } const tokens = { access_token: credentials.access_token, refresh_token: credentials.refresh_token, expiry_date: credentials.expiry_date, }; // Persist refreshed tokens if callback is provided if (this.onTokenRefresh) { await this.onTokenRefresh(tokens); } return tokens; } async getEventsForDate(dateStr: string): Promise<CalendarEvent[]> { if (!this.calendar || !this.oauth2Client) { throw new Error('Google Calendar not initialized'); } // Validate YYYY-MM-DD format if (!/^\d{4}-\d{2}-\d{2}$/.test(dateStr)) { throw new Error('Date must be in YYYY-MM-DD format (e.g., "2025-12-01")'); } // Parse date for local day start/end times const [year, month, day] = dateStr.split('-').map(Number); const dayStart = new Date(year, month - 1, day, 0, 0, 0); const dayEnd = new Date(year, month - 1, day, 23, 59, 59); try { // Check if token needs refresh const expiryDate = this.oauth2Client.credentials.expiry_date; if (expiryDate && expiryDate < Date.now()) { await this.refreshAccessToken(); } const response = await this.calendar.events.list({ calendarId: 'primary', timeMin: dayStart.toISOString(), timeMax: dayEnd.toISOString(), singleEvents: true, orderBy: 'startTime', }); const events = response.data.items || []; return events .filter(event => { // Filter out all-day events and events without start/end times return event.start?.dateTime && event.end?.dateTime; }) .map(event => ({ title: event.summary || 'Untitled Event', start: new Date(event.start!.dateTime!), end: new Date(event.end!.dateTime!), attendees: event.attendees?.length || 0, })); } catch (error: any) { if (error.code === 401) { // Token expired, try to refresh await this.refreshAccessToken(); return this.getEventsForDate(dateStr); } throw error; } } isAuthenticated(): boolean { return this.oauth2Client !== null && this.oauth2Client.credentials.access_token !== undefined; } }