import pymysql.cursors
from collections import namedtuple

data_set = []
#FB_subject, phrase, FB_object, relation
data_set.append({"FB_subject_name":"Kevin Costner","phrase":"was awarded the","FB_object_name":"Honorary César",
    "relation":"award.award_winner.awards_won..award.award_honor.award"})
data_set.append({"FB_subject_name":"Kevin Costner","phrase":"won the","FB_object_name":"Honorary César",
    "relation":"award.award_winner.awards_won..award.award_honor.award"})
data_set.append({"FB_subject_name":"Leonardo di Caprio","phrase":"won the","FB_object_name":"Oscar",
    "relation":"award.award_winner.awards_won..award.award_honor.award"})

def precision_recall_evaluation():
    #phraseInfo = namedtuple("phraseInfo", "phrase true_positives false_positives true_negatives false_negatives")
    true_positives = 0.0
    false_positives = 0.0
    true_negatives = 0.0
    false_negatives = 0.0
    #phrases = {}

    #Precision = true_positives/false_positives + true_positives
    #Recall = true_positives/ true_positives + false negatives
    connection = pymysql.connect(host= 'localhost',
                                user = 'root',
                                password = 'mysql',
                                db = 'lector',
                                charset ='utf8mb4',
                                cursorclass = pymysql.cursors.DictCursor)
    try:
        with connection.cursor() as cursor:
            sql = "SELECT FB_subject_name,phrase,FB_object_name,relation FROM extracted_facts WHERE FB_subject_name = %s AND FB_object_name = %s"
            for row in data_set:
                cursor.execute(sql,(row["FB_subject_name"],row["FB_object_name"]))
                result = cursor.fetchall()

                if result == (): #data set con recall max
                    false_negatives += 1

                for element in result:
                    if element["phrase"] == row["phrase"] and element["relation"] == row["relation"]:
                        true_positives += 1
                    elif element["relation"] != row["relation"]:
                        false_positives += 1

                    if element["phrase"] != row["phrase"] and element["relation"] == row["relation"]:
                        false_negatives += 1
                    elif element["relation"] != row["relation"]:
                        true_negatives +=1

            precision = true_positives/(true_positives+false_positives)
            recall = true_positives/(true_positives+false_negatives)

            print "Precision = %f" %precision
            print "Recall = %f" %recall

    finally:
        connection.close()


if __name__ == "__main__":
    precision_recall_evaluation()