import psycopg2
import datetime


def connect(dbname, user, host, password)
    """ Attempts to connect to a PostgreSQL database """
    try:
        conn = psycopg2.connect(
            "dbname='{0}' user='{1}' host='{2}' password='{3}",
            "'".format(dbname, user, host, password))
    except:
        print "Cannot connect to 'news' database"


def top_articles(limit):
    """ Top news articles sorted by popularity """
    cursor = conn.cursor()
    cursor.execute(
        "SELECT COUNT(id), path FROM log WHERE status = '200 OK' ",
        "AND NOT path = '/' GROUP BY path ",
        "ORDER BY COUNT(id) DESC LIMIT {0};".format(limit))

    print "Top {0} articles sorted by popularity: ".format(limit)
    print

    articles = cursor.fetchall()
    for article in articles:
        cursor.execute(
            "SELECT title FROM articles WHERE ",
            "('/article/' || slug) ='" + article[1] + "';")
        title = cursor.fetchone()
        print '"{0}" - {1} views'.format(title[0], article[0])


def top_authors(limit):
    """ Top authors sorted by total article views """
    cursor = conn.cursor()
    cursor.execute("SELECT name, id FROM authors LIMIT {0};".format(limit))

    print "Top {0} authors sorted by page views: ".format(limit)
    print

    authors = cursor.fetchall()
    for author in authors:
        cursor.execute(
            "SELECT slug FROM articles WHERE author ='{0}';".format(author[1]))
        slugs = cursor.fetchall()
        total_views = 0
        for slug in slugs:
            cursor.execute(
                "SELECT COUNT(id) FROM log WHERE status = '200 OK' ",
                "AND substring(path, 10) = '{0}';".format(slug[0]))
            art_count = cursor.fetchone()
            total_views += art_count[0]
        print "{0} - {1} views".format(author[0], total_views)


def bad_request_days():
    """ Days where there were bad requests over 1% """
    cursor = conn.cursor()
    cursor.execute(
        "SELECT COUNT(id), time, status FROM log GROUP BY ",
        "time, status ORDER BY time;")

    last_row = None
    total_bad = 0.0
    total_good = 0.0

    print "Days with more than 1% errors:"
    print

    for row in cursor:
        if last_row is None:
            last_row = row[1]

        if last_row.month == row[1].month and last_row.day == row[1].day:
            if row[2] == "404 NOT FOUND":
                total_bad += row[0]
            elif row[2] == "200 OK":
                total_good += row[0]
        else:
            result = float(total_bad / (total_bad + total_good) * 100)
            if result > 1.0:
                print "{0}/{1}/{2} - {3:.2f}%",
                    "%".format(last_row.month, last_row.day,
                               last_row.year, result)

            last_row = None
            total_bad = 0.0
            total_good = 0.0


if __name__ == "__main__":
    connect("news", "postgres", "localhost", "pass")
    top_articles(3)
    print
    top_authors(4)
    print
    bad_request_days()