# Credit goes to Websten from forums
#
# Use Dave's suggestions to finish your daysBetweenDates
# procedure. It will need to take into account leap years
# in addition to the correct number of days in each month.

def nextDay(year, month, day):
    """Increments year-month-day to the next day."""
    if day < daysInMonth(year, month):
        return year, month, day + 1
    else:
        if month == 12:
            return year + 1, 1, 1
        else:
            return year, month + 1, 1

def isLeapYear(year):
    """Returns True if year is a leap year; otherwise, returns False"""
    if year % 4 != 0:
        return False
    if year % 100 != 0:
        return True
    if year % 400 != 0:
        return False
    return True

def daysInMonth(year, month):
    """Returns number of days in a month, adjusting for leap year."""
    days_of_months = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    if month == 2 and isLeapYear(year):
        return days_of_months[month - 1] + 1
    else:
        return days_of_months[month - 1]

def dateIsBefore(year1, month1, day1, year2, month2, day2):
    """Returns True if year1-month1-day1 is before year2-month2-day2. Otherwise, returns False."""
    if year1 < year2:
        return True
    if year1 == year2:
        if month1 < month2:
            return True
        if month1 == month2:
            return day1 < day2
    return False


def daysBetweenDates(year1, month1, day1, year2, month2, day2):
    """Returns the number of days between year1/month1/day1
       and year2/month2/day2. Assumes inputs are valid dates
       in Gregorian calendar."""
    # program defensively! Add an assertion if the input is not valid!
    assert not dateIsBefore(year2, month2, day2, year1, month1, day1)
    days = 0
    while dateIsBefore(year1, month1, day1, year2, month2, day2):
        year1, month1, day1 = nextDay(year1, month1, day1)
        days += 1
    return days


def test():
    test_cases = [((2012, 1, 1, 2012, 2, 28), 58),
                  ((2012, 1, 1, 2012, 3, 1), 60),
                  ((2011, 6, 30, 2012, 6, 30), 366),
                  ((2011, 1, 1, 2012, 8, 8), 585),
                  ((1900, 1, 1, 1999, 12, 31), 36523)]

    for (args, answer) in test_cases:
        result = daysBetweenDates(*args)
        if result != answer:
            print "Test with data:", args, "failed"
        else:
            print "Test case passed!"


test()
