from flask_pymongo import PyMongo

mongo = PyMongo()

def init_db(app):
    """
    Initialize the MongoDB connection with the Flask app.

    Args:
        app (Flask): The Flask application instance.
    """
    mongo.init_app(app)

def get_all_patients():
    """
    Retrieve all patients and generate a textual summary for each.

    Returns:
        list: A list of strings, each summarizing a patient's data.
    """
    try:
        patients_collection = mongo.db.patients
        patients = list(patients_collection.find())
        all_patient_text = []
        for p in patients:
            summary = f"Patient ID: {p.get('_id')}\n"
            summary += f"Name: {p.get('name')}\n"
            summary += f"Age: {p.get('age')}\n"
            summary += f"Gender: {p.get('gender')}\n"
            if p.get('symptoms'):
                summary += f"Symptoms: {p.get('symptoms')}\n"
            if p.get('diagnosis'):
                summary += f"Diagnosis: {p.get('diagnosis')}\n"
            if p.get('treatment'):
                summary += f"Treatment: {p.get('treatment')}\n"
            if p.get('medical_history'):
                summary += f"Medical History: {p.get('medical_history')}\n"
            all_patient_text.append(summary)
        return all_patient_text
    except Exception as e:
        print(f"Error fetching patients: {e}")
        return []

def get_next_id(collection_name):
    """
    Generate the next sequential integer ID for a given collection.
    
    This is used to maintain backward compatibility with legacy checks requiring integer IDs.
    
    Args:
        collection_name (str): The name of the MongoDB collection.

    Returns:
        int: The next available integer ID.
    """
    try:
        last_item = mongo.db[collection_name].find_one(sort=[("id", -1)])
        if last_item and 'id' in last_item:
            return int(last_item['id']) + 1
        return 1
    except Exception:
        return 1