import pymongo

client = pymongo.MongoClient()
db = client["bdm"]


def find_distinct_cities(db, collection_name):
    cities = db[collection_name].find().distinct("city")
    cities.sort()
    return cities


def count_reviews_since(db, collection, since):
    return db[collection].count_documents({
        "date": {"$gte": since}
    })


def find_closed(db, collection_name):
    return db[collection_name].find(
        {"open": False},
        {"_id": 0, "name": 1, "full_address": 1, "stars": 1}
    )


def find_no_positive_reviews(db, collection_name):
    return db[collection_name].find({
        "$and": [{"votes.funny": 0}, {"votes.useful": 0}]
    }).sort("name")


def remove_by_rating(db, collection_name, rating=2):
    db[collection_name].delete_many({"stars": rating})


def find_number_of_tips(db, collection_name):
    pipeline = [
        {"$group": {"_id": "$business_id",
                    "count": {"$sum": 1}}},
        {"$sort": {"count": 1}}
    ]
    return db[collection_name].aggregate(pipeline)


def find_average_rating(db, collection_name):
    pipeline = [
        {"$group": {"_id": "$business_id",
                    "average": {"$avg": "$stars"}}},
        {"$match": {"average": {"$gte": 4}}}
    ]
    return db[collection_name].aggregate(pipeline)


if __name__ == '__main__':
    for i in find_average_rating(db, "review"):
        print(i)