ratings.py

from openlibrary.utils.dateutil import DATE_ONE_MONTH_AGO, DATE_ONE_WEEK_AGO

from . import db


class Ratings(object):

    VALID_STAR_RATINGS = range(6)  # inclusive: [0 - 5] (0-5 star)

    @classmethod
    def summary(cls):
        return {
            'total_books_starred': {
                'total': Ratings.total_num_books_rated(),
                'month': Ratings.total_num_books_rated(since=DATE_ONE_MONTH_AGO),
                'week': Ratings.total_num_books_rated(since=DATE_ONE_WEEK_AGO),
                'unique': Ratings.total_num_unique_raters()
            }
        }

    @classmethod
    def total_num_books_rated(cls, since=None, distinct=False):
        oldb = db.get_db()
        query = "SELECT count(%s work_id) from ratings" % ('DISTINCT' if distinct else '')
        if since:
            query += " WHERE created >= $since"
        results = oldb.query(query, vars={'since': since})
        return results[0] if results else None

    @classmethod
    def total_num_unique_raters(cls, since=None):
        oldb = db.get_db()
        query = "select count(DISTINCT username) from ratings"
        if since:
            query += " WHERE created >= $since"
        results = oldb.query(query, vars={'since': since})
        return results[0] if results else None

    @classmethod
    def most_rated_books(cls, limit=10, since=False):
        oldb = db.get_db()
        query = 'select work_id, count(*) as cnt from ratings '
        if since:
            query += " WHERE created >= $since"
        query += ' group by work_id order by cnt desc limit $limit'
        return list(oldb.query(query, vars={'limit': limit, 'since': since}))

    @classmethod
    def get_users_ratings(cls, username):
        oldb = db.get_db()
        query = 'select * from ratings where username=$username'
        return list(oldb.query(query, vars={'username': username}))

    @classmethod
    def get_rating_stats(cls, work_id):
        oldb = db.get_db()
        query = ("SELECT AVG(rating) as avg_rating, COUNT(DISTINCT username) as num_ratings"
                 " FROM ratings"
                 " WHERE work_id = $work_id")
        result = oldb.query(query, vars={'work_id': int(work_id)})
        return result[0] if result else {}

    @classmethod
    def get_all_works_ratings(cls, work_id):
        oldb = db.get_db()
        query = 'select * from ratings where work_id=$work_id'
        return list(oldb.query(query, vars={'work_id': work_id}))

    @classmethod
    def get_users_rating_for_work(cls, username, work_id):
        oldb = db.get_db()
        data = {
            'username': username,
            'work_id': int(work_id)
        }
        query = 'SELECT * from ratings where username=$username AND work_id=$work_id'
        results = list(oldb.query(query, vars=data))
        rating = results[0].rating if results else None
        return rating

    @classmethod
    def remove(cls, username, work_id):
        oldb = db.get_db()
        where = {
            'username': username,
            'work_id': int(work_id)
        }
        try:
            return oldb.delete('ratings', where=(
                'work_id=$work_id AND username=$username'), vars=where)
        except:  # we want to catch no entry exists
            return None

    @classmethod
    def add(cls, username, work_id, rating, edition_id=None):
        from openlibrary.core.bookshelves import Bookshelves

        oldb = db.get_db()
        work_id = int(work_id)
        data = {'work_id': work_id, 'username': username}

        if rating not in cls.VALID_STAR_RATINGS:
            return None

        # Vote implies user read book; Update reading log status as "Already Read"
        users_read_status_for_work = Bookshelves.get_users_read_status_of_work(username, work_id)
        if users_read_status_for_work != Bookshelves.PRESET_BOOKSHELVES['Already Read']:
            Bookshelves.add(username, Bookshelves.PRESET_BOOKSHELVES['Already Read'],
                            work_id, edition_id=edition_id)

        users_rating_for_work = cls.get_users_rating_for_work(username, work_id)
        if not users_rating_for_work:
            return oldb.insert('ratings', username=username,
                               work_id=work_id, rating=rating, edition_id=edition_id)
        else:
            where = "work_id=$work_id AND username=$username"
            return oldb.update('ratings', where=where,
                               rating=rating,  vars=data)