import os
import json
from googleapiclient.discovery import build
from google.oauth2.credentials import Credentials

def get_calendar_service():
    if os.getenv("ENABLE_CALENDAR") != "true":
        return None
    
    try:
        creds_json = os.getenv("GOOGLE_CALENDAR_CREDS_JSON")
        if not creds_json:
            return None
            
        creds_data = json.loads(creds_json)
        creds = Credentials.from_authorized_user_info(creds_data["installed"])
        return build("calendar", "v3", credentials=creds)
    except Exception as e:
        print(f"Calendar setup failed: {str(e)}")
        return None

def add_to_calendar(service, title, deadline):
    if not service:
        return "Calendar disabled"
    
    event = {
        "summary": title,
        "start": {"dateTime": deadline},
        "end": {"dateTime": deadline}
    }
    
    try:
        service.events().insert(calendarId="primary", body=event).execute()
        return "✅ Added to calendar"
    except Exception as e:
        return f"❌ Calendar error: {str(e)}"