day10.py

import re


class Bot:
    def __init__(self, group, low, high):
        self._queue = []
        self._low_target = low
        self._high_target = high
        self._group = group

    def give(self, value):
        self._queue.append(value)

    def ready(self):
        return len(self._queue) >= 2

    def run(self):
        a, b = self.shift()
        if a > b: a, b = b, a
        self._group.send(self._low_target, a)
        self._group.send(self._high_target, b)

    def shift(self):
        item_a, item_b = self._queue[:2]
        self._queue = self._queue[2:]
        return [item_a, item_b]

    def peek(self):
        return self._queue[:2]


class BotGroup:
    def __init__(self):
        self._bots = {}
        self._outputs = {}
        self._part1 = None

    def send(self, target, value):
        if target[1] == 'bot':
            self._bots[target[0]].give(value)
        elif target[1] == 'output':
            self._outputs[target[0]] = value

    def create(self, id, low, high):
        if not id in self._bots: self._bots[id] = Bot(self, low, high)

    def load_file(self, filename):
        bot_re = re.compile(r'bot (\d+) gives low to (bot|output) (\d+) and high to (bot|output) (\d+)')
        give_re = re.compile(r'value (\d+) goes to bot (\d+)')
        gives = []

        with open(filename) as f:
            for line in f:
                bmatch = bot_re.match(line)
                gmatch = give_re.match(line)

                if bmatch:
                    print(line)
                    self.create(int(bmatch[1]), (int(bmatch[3]), bmatch[2]), (int(bmatch[5]), bmatch[4]))
                elif gmatch:
                    gives.append((int(gmatch[2]), int(gmatch[1])))

        for give in gives:
            print(give)
            self._bots[give[0]].give(give[1])

    def run_part1(self):
        while True:
            any_ready = False
            for id, bot in self._bots.items():
                if bot.ready():
                    any_ready = True
                    a, b = bot.peek()
                    if (a == 61 and b == 17) or (a == 17 and b == 61):
                        self._part1 = self._part1 or id
                    bot.run()
            if not any_ready: break

    def part1(self):
        return self._part1

    def part2(self):
        return self._outputs[0] * self._outputs[1] * self._outputs[2]


bg = BotGroup()
bg.load_file('day10.txt')
bg.run_part1()
print('Part 1: %d' % bg.part1())
print('Part 2: %d' % bg.part2())