'''AoC day 2'''

def get_new_pos(curr_pos, instruction):
    if instruction == '<':
        new_pos = (curr_pos[0] - 1, curr_pos[1])
    elif instruction == '>':
        new_pos = (curr_pos[0] + 1, curr_pos[1])
    elif instruction == '^':
        new_pos = (curr_pos[0], curr_pos[1] + 1)
    elif instruction == 'v':
        new_pos = (curr_pos[0], curr_pos[1] - 1)
    else:
        new_pos = (0, 0)

    return new_pos


def process_instructions(instruction_set: str) -> int:
    '''Run through a set of instructions to return the number of unique houses visited

    Keyword args:
    instruction_set (str) - Directional arrow instruction string giving moves to new locations

    Returns:
    int - Number of unique houses visited
    '''
    visited_house_coordinates = {(0,0)}
    curr_pos = (0, 0)

    for instruction in instruction_set:
        curr_pos = get_new_pos(curr_pos, instruction)

        visited_house_coordinates.add(curr_pos)

    return len(visited_house_coordinates)

def process_robo_instructions(instruction_set: str) -> int:
    visited_house_coordinates = {(0,0)}
    santa_pos = (0,0)
    robot_pos = (0,0)

    for index, instruction in enumerate(instruction_set):
        if index % 2 == 0:
            santa_pos = get_new_pos(santa_pos, instruction)
            visited_house_coordinates.add(santa_pos)
        else:
            robot_pos = get_new_pos(robot_pos, instruction)
            visited_house_coordinates.add(robot_pos)

    return len(visited_house_coordinates)

def main():
    '''Entrypoint'''
    with open('input.txt', encoding='utf-8') as fh:
        instruction_set = fh.readline()
        unique_houses = process_instructions(instruction_set)

        print(f'Part1: {unique_houses}')

        robo_houses = process_robo_instructions(instruction_set)

        print(f'Part2: {robo_houses}')


if __name__ == "__main__":
    main()