RankingAlgorithm

# Imports the Google Cloud client library
from google.cloud import language
from google.cloud.language import enums
from google.cloud.language import types

# Instantiates a client
client = language.LanguageServiceClient()


def course_review_score(reviews_list):
    """ calculates the final score to be given to a course taking in to account
        all the ratings
    """
    score = 0
    score_list = []
    for review in reviews_list: # going through all reviews in the list of reviews
        the_review = one_review_score(review) # calling the function to get sentiment analysis of a particular review
        total = the_review[0] * the_review[1] # multiplying the sentiment score and magnitude
        score_list.append(total)

    return sum(score_list) # course review score will be sum of all courses in the list


def one_review_score(review):
    """ calculates the sentiment score of a particular review """
    # The text to analyze
    text = review
    document = types.Document(content=text, type=enums.Document.Type.PLAIN_TEXT)

    # Detects the sentiment of the text
    sentiment = client.analyze_sentiment(document=document).document_sentiment
    return sentiment.score, sentiment.magnitude

def sorting_courses(course_list):
    """ sorts all the courses based on the review scores/ratings """
    
    ranking_courses = [[course_review_score(course), course] for course in course_list] # creating a list of all course scores with the courses
    ranking_courses.sort(reverse = True) # courses are now sorted in descending order of their course scores

    # CHECK IF YOU NEED TO DO ranking_courses = ranking_courses.sort(reverse = True) INSTEAD

    course_list = [x[1] for x in ranking_courses] # courses have been ranked in descending order!

    return course_list