from firebase_admin import firestore
import os
import firebase_admin
from datetime import datetime, timedelta
from google.cloud.firestore_v1.base_query import FieldFilter

def delete_documents_in_batch(collection_ref, batch_size):
    # Query to get all documents
    query = collection_ref.order_by('testTime', direction=firestore.Query.DESCENDING).limit(batch_size)
    documents = query.stream()

    batch = collection_ref._client.batch()  # Internal batch object

    # Delete documents in batch
    count = 0
    for doc in documents:
        # print(doc.to_dict)
        batch.delete(doc.reference)
        count += 1

    # Commit the batch
    batch.commit()
    print(f'Deleted {count} documents in batch')


def delete_latest_documents(collection_name, num_documents, batch_size):

    file_path = os.getcwd() + '/keys' + '/hpos-af3cc-firebase-adminsdk.json'
    cred = firebase_admin.credentials.Certificate(fr'{file_path}')

    firebase_admin.initialize_app(cred)

    # Initialize Firestore client
    db = firestore.client()

    # Reference to the collection
    collection_ref = db.collection(collection_name)

    # Delete documents in batches
    remaining_documents = num_documents
    while remaining_documents > 0:
        current_batch_size = min(remaining_documents, batch_size)
        delete_documents_in_batch(collection_ref, current_batch_size)
        remaining_documents -= current_batch_size


if __name__ == "__main__":
    # Specify your Firestore collection name
    collection_name = 'testData'

    num_documents = 100
    batch_size = 5

    # Call the function to delete the latest documents in batches
    delete_latest_documents(collection_name, num_documents, batch_size)