push_deadlines.py

from datetime import datetime,timedelta
import os.path
import pytz
from retrieval import fetch_deadlines
from email_parser import fetch_today_email_deadlines

from google.auth.transport.requests import Request
from google.oauth2.credentials import Credentials
from google_auth_oauthlib.flow import InstalledAppFlow
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError


SCOPES = [
    "https://www.googleapis.com/auth/gmail.modify",
    "https://www.googleapis.com/auth/calendar",
] # union of scopes used across the app


# authenticating
def get_calendar_service():
    """Authenticate and return Google Calendar API service."""
    creds = None
    if os.path.exists("token.json"):
        creds = Credentials.from_authorized_user_file("token.json", SCOPES)

    if not creds or not creds.valid:
        if creds and creds.expired and creds.refresh_token:
            creds.refresh(Request())
        else:
            flow = InstalledAppFlow.from_client_secrets_file(
                "client_secret.json", SCOPES
            )
            creds = flow.run_local_server(port=0)
        with open("token.json", "w") as token:
            token.write(creds.to_json())

    return build("calendar", "v3", credentials=creds)



def push_event(service, deadlines):
    """Push deadlines dict to Google Calendar."""
    try:
        # Example from deadliness dict: "Sunday, August 03, 2025 12:00 AM"
        for deadline in deadlines :
            due_str = deadline["Due_date"]
            due_dt = datetime.strptime(due_str, "%A, %B %d, %Y %I:%M %p")


            tz = pytz.timezone("Asia/Kolkata") # changing to my timezone
            due_dt = tz.localize(due_dt)

            due_dt -= timedelta(days=1) # adding the event to the calendar on prev day itself so that i dont have to worry abt it on the last minute🥸


            due_iso = due_dt.isoformat() # formatting it into RFC3339 (ISO8601) string (the format Google Calendar expects).

            event = {
                "summary": deadline["Name"],
                "description": "Deadlines extracted from LMS/Email",
                "start": {"dateTime": due_iso, "timeZone": "Asia/Kolkata"},
                "end": {"dateTime": due_iso, "timeZone": "Asia/Kolkata"},
            }

            created = service.events().insert(calendarId="primary", body=event).execute()
            print("Event added:", created.get("htmlLink"))

    except HttpError as error:
        print(f"An error occurred: {error}")


def main():
    service = get_calendar_service()
    # Fetch LMS deadlines for the month
    lms_deadlines = fetch_deadlines()
    # Fetch today's email-derived deadlines
    email_deadlines = fetch_today_email_deadlines()

    combined = list(lms_deadlines) + list(email_deadlines)

    if not combined:
        print("No deadlines to push today.")
        return

    push_event(service, combined)


if __name__ == "__main__":
    main()