# write a function that manages a simple elevator.
# The function takes one argument, the floor number.
# Assume there are floor numbers 1, 2, 3, 4

# When the function is invoked,
# it checks if the door is currently open.
# If the door is open, it prints "close"
# (i.e., close the door before moving the elevator)

# The function then checks the floor the elevator is currently at.
# It then prints "up" (or "down")
# if the elevator needs to go up (or down)
# to the given floor number, followed by "open" (to open the door).

# Hint: don't forget to keep track of the current floor number
#       and current status of the door (global vs local !!)

# Example:
#   If function is invoked with the floor number 3
#   The elevator is currently at floor number 1 (door closes)
#   the output will be "up up"
#
#   If function is invoked with the floor number 3
#   The elevator is currently at floor number 1 (door opens)
#   the output will be "close up up"


# let's initialize the variables
current_floor = 1
is_open = False   # door is close

def move_elevator(goto_floor):
    global current_floor
    global is_open

    result = ""

    if current_floor > goto_floor:
        move = current_floor - goto_floor
        if is_open:
            result = "close "
            is_open = False
        result += "down " * move
        result += "open "
        is_open = True
    else:
        move = goto_floor - current_floor
        if is_open:
            result = "close "
            is_open = False
        result += "up " * move
        result += "open "
        is_open = True

    print(result)
    current_floor = goto_floor



move_elevator(1)
move_elevator(3)
move_elevator(1)
move_elevator(4)
move_elevator(2)


# practice writing function
# understand global and local variables
# practice conditional statements
# work with strings