from pymongo import MongoClient
from bson.objectid import ObjectId
class AnimalShelter(object):
    """
    CRUD operations for Animal collection in MongoDB
    """

    def __init__(self, **kwargs):
        """
        Constructor for the AnimalShelter class, initializes the MongoDB connection

        :param user:
            The MongoDB database user to connect with
            (default: 'aacuser')
        :param password:
            The password for the aforementioned MongoDB user
            (no default... use your own!)
        :param host:
            The MongoDB server hostname/IP to connect to
            (default: 'localhost')
        :param port:
            The TCP port that the MongoDB server is listening on
            (default: 27017)
        :param db:
            The Animal Shelter MongoDB database
            (default: 'AAC')
        :param collection:
            MongoDB Collection for the animal records
            (default: 'animals')
        """

        USER = kwargs.get('user', 'aacuser')
        PASS = kwargs.get('password', None)
        HOST = kwargs.get('host', 'localhost')
        PORT = kwargs.get('port', 27017)
        DB = kwargs.get('db', 'AAC')
        COL = kwargs.get('collection', 'animals')

        #
        # Initialize Connection
        #
        self.client = MongoClient('mongodb://%s:%s@%s:%d' % (USER,PASS,HOST,PORT))
        self.database = self.client['%s' % (DB)]
        self.collection = self.database['%s' % (COL)]

# Create
    def create(self, **kwargs):
        """
        Creates collection objects using a defined dictionary

        :param data:
            Dictionary with the data that will be created in the database
        """
        data = kwargs.get('data', None)
        if data is not None:
            try:
                self.database.animals.insert_one(data)
                return True
            except Exception as e:
                print(f'Exception: {e}') # Exception handling
                return False # Failed operation, so return false
        else:
            print("Nothing to save, because data parameter is empty") # Case of empty 'data' parameter
            return False # Failed operation, so return false
# Read
    def read(self, **kwargs):
        """
        Accepts a query and returns a list of dictionaries with the requested data from the collection

        :param query:
            The filter that will be used to query the database
        """
        query = kwargs.get('query', None)
        dataList = []
        try:
            dataList = [doc for doc in self.collection.find(query)] # MongoDB cursor, we need to convert this to a list of dicts
            return dataList # Return the list
        except Exception as e:
            print(f'Exception: {e}') # Exception handling
            return False # Failed operation, so return false
# Update
    def update(self, **kwargs):
        """
        Updates objects in the collection based on the query, update type, and incoming dict of data

        :param query:
            The filter that will be used to query the database for the objects that will be updated
        :param update_type:
            The type of update to be performed, accepts any MongoDB Field Update Operator
            (https://www.mongodb.com/docs/manual/reference/operator/update-field/)
        :param data:
            The incoming data (dictionary) to update with
            Not required depending on the update_type specified
        """
        query = kwargs.get('query', None)
        update_type = kwargs.get('update_type', None)
        data = kwargs.get('data', None)
        try:
            self.collection.update_many(query, {f'${update_type}': data}) # Query DB + update with data
            return True # Operation was successful, so return true
        except Exception as e:
            print(f'Exception: {e}') # Exception handling
            return False # Failed operation, so return false

# Delete
    def delete(self, **kwargs):
        """
        Deletes objects in the collection based on the query

        :param query:
            The filter that will be used to query the database for objects that will be deleted
        """
        query = kwargs.get('query', None)
        try:
            self.collection.delete_many(query)
            return True # Operation was successful, so return true
        except Exception as e:
            print(f'Exception: {e}') # Exception handling
            return False # Failed operation, so return false