zerosleeps

from pathlib import Path
import re

def get_raw_input():
    return (Path(__file__).parent/'day_19_input.txt').read_text()

def parse_raw_input(raw_input):
    rules, messages = [
        [ line.strip() for line in section.splitlines() ]
        for section in raw_input.strip().split('\n\n')
    ]

    rules = {
        int(rule.split(': ')[0]): rule.split(': ')[1].replace('"', '')
        for rule in rules
    }

    return rules, messages

def check_rules(rules, messages):
    # While any rule other than zero contains a number that isn't it's own number
    while any([
        re.search(fr'(?!\b{rule_id}\b)\b\d+\b', rule)
        for rule_id, rule
        in rules.items()
        if rule_id != 0
    ]):
        for rule_id, rule in rules.items():
            if not re.search(r'\d', rule) or re.search(fr'\b{rule_id}\b', rule):
                # Rule contains no digits, or it references itself
                # Wrap in brackets to preserve any logical 'or'
                if '|' in rule:
                    rule = f'({rule})'
                # Replace any references to this rule in all rules
                for replacement_rule_id, replacement_rule in rules.items():
                    rules[replacement_rule_id] = re.sub(fr'\b{rule_id}\b', rule, replacement_rule)

    rule_zero = re.compile(rules[0].replace(' ',''))
    return len([message for message in messages if re.fullmatch(rule_zero, message)])

def part_two(raw_input):
    rules, messages = parse_raw_input(raw_input)
    rules.update({
        8: '42 | 42 8',
        11: '42 31 | 42 11 31'
    })
    return check_rules(rules, messages)

if __name__ == '__main__':
    print(f'Part one: {check_rules(*parse_raw_input(get_raw_input()))}')
    print(f'Part two: {part_two(get_raw_input())}')