# https://www.freecodecamp.org/learn/scientific-computing-with-python/scientific-computing-with-python-projects/time-calculator

############ time_calculator.py ###################


def add_time(start, duration, startday=None): 
    
    start = start.split(' ')
    duration = duration.split(' ')
    a = start[0].split(':')
    b = duration[0].split(':')  
    
    l = int(a[1]) + int(b[1])
    k = int(a[0]) + int(b[0]) + int((l // 60))
    
    d = k // 24
    e = k % 12
    
    if e == 0:
        e = 12

    if startday != None:        
        days = ('Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday')
        index = days.index(startday)
        c = list(days[index:] + days)[:7]        
        if d == 0 and k >= 12 and start[1] == 'PM':
            return f'{e}:{l} AM {c[1]} (next day)'
        
    if d == 0 and k >= 12 and start[1] == 'PM':
        return f'{e}:{l} AM (next day)'    
        
    if l > 60 and a[0] == '11' and start[1] == 'PM':
        start[1] = 'AM'
        d = d + 1
    elif l > 60 and a[0] == '11' and start[1] == 'AM':
        start[1] = 'PM'   
    elif (k // 12) % 2 == 1 and start[1] == 'PM':
        start[1] = 'AM' 
        d = d + 1
        
    if l > 60:
        l = l % 60
        
    g = str(l)
    if l < 10: 
        l = str('0'+ g)  
        
    if startday != None:    
        if d == 0:
            return f'{e}:{l} {start[1]} {c[0]}'
        elif d == 1:
            return f'{e}:{l} {start[1]} {c[1]} (next day)'
        elif d > 1:
            return f'{e}:{l} {start[1]} {c[(d % 7)]} ({d} days later)'
    else:
        if d == 0:
            return f'{e}:{l} {start[1]}'
        elif d == 1:
            return f'{e}:{l} {start[1]} (next day)'
        elif d > 1:
            return f'{e}:{l} {start[1]} ({d} days later)'
        
print(add_time("3:30 PM", "2:12", "Monday"))

   # a start time in the 12-hour clock format (ending in AM or PM)
  #  a duration time that indicates the number of hours and minutes
   # (optional) a starting day of the week, case insensitive
    
  #  If the result will be the next day, it should show (next day) after the time. 
# If the result will be more than one day later, it should show (n days later) after the time, where "n" is the number of days later.

# If the function is given the optional starting day of the week parameter, then the output should display the day of the week of the result. 
# The day of the week in the output should appear after the time and before the number of days later.