from pymongo import MongoClient
from datetime import datetime, timedelta
from typing import Dict, Union

def get_current_date() -> str:
    # Get the current date and return it in YYYY-MM-DD format
    return datetime.now().date().isoformat()

def get_another_date(day: int) -> str:
    # Get the current date and add specified days to it
    tomorrow = datetime.now() + timedelta(days=day)
    return tomorrow.date().isoformat()

def check_date_streak(start_date: str, end_date: str) -> bool:
    # Convert ISO strings to datetime objects
    start_date = datetime.fromisoformat(start_date)
    end_date = datetime.fromisoformat(end_date)
    
    # Compare the dates to check if they are consecutive (1 day apart)
    return end_date - start_date == timedelta(days=1)

def streaks_manager(db_uri: str, document: Dict) -> Union[bool, str]:
    """
    Manage user streaks in MongoDB.

    Args:
        db_uri: MongoDB connection string
        document: Dictionary containing user data with 'user_id' key

    Returns:
        Union[bool, str]: True if successful, "User Already Exists" if streak is reset
    """
    client = MongoClient(db_uri)
    try:
        db = client["crayonics"]
        collection = db["Streaks"]
        
        # Check for existing user
        found_user = collection.find_one({"user_id": document.get('user_id')})
        current_date = get_current_date()
        document['streak_dates'] = [current_date]

        if found_user is None:
            # New user case
            collection.insert_one(document)
            return True
        else:
            is_a_streak = check_date_streak(
                start_date=found_user['streak_dates'][-1],
                end_date=current_date
            )
            if is_a_streak:
                print("its a streak guys")
                # Extend existing streak
                dates = found_user["streak_dates"] + [current_date]
                collection.update_one(
                    {"user_id": document.get("user_id")},
                    {"$set": {"streak_dates": dates}}
                )
                return True
            else:
                # Reset streak if not consecutive
                collection.find_one_and_replace(
                    {"user_id": document.get('user_id')},
                    document
                )
                return "User Already Exists"
                
    except Exception as e:
        print(f"Error: {str(e)}")
        raise
    finally:
        client.close()