#!/usr/bin/env python
# -*- encoding: utf-8; py-indent-offset: 4 -*-

# Author: Sebastian Mark
# CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)

# pylint: disable=missing-module-docstring,missing-function-docstring,consider-using-f-string


from collections import defaultdict


def readinput() -> list:
    with open("input", "r", encoding="utf-8") as file:
        lines = file.readlines()
    return lines


def get_orders_and_updates() -> tuple[list, list]:
    lines = readinput()

    sep = lines.index("\n")  # newline in input

    rules = defaultdict(set)
    for line in lines[:sep]:
        a, b = map(int, line.split("|"))
        rules[a].add(b)

    updates = []
    for line in lines[sep + 1 :]:
        updates.append(list(map(int, line.split(","))))

    return (rules, updates)


def validate_rules(update: list, rules: list) -> bool:
    for i in range(len(update) - 1):
        next_page = update[i + 1]
        page = update[i]
        if next_page not in rules[page]:
            return False
    return True


def get_middle_number(update: list) -> int:
    return update[int(len(update) / 2)]


def fix_with_rules(update: list, rules: list) -> list:
    # this block is inspired by:
    # https://github.com/nitekat1124/advent-of-code-2024/blob/main/solutions/day05.py

    # filter only the rules for the pages in the current update
    filtered_rules = defaultdict(set)
    for i in update:
        new_rules = []
        for x in rules[i]:
            if x in update:
                new_rules.append(x)
        filtered_rules[i] = new_rules

    # the more filtered rules for the value exist,
    # the further to the end is has to be placed,
    # then reverse this
    ordered_keys = sorted(
        filtered_rules, key=lambda val: len(filtered_rules[val]), reverse=True
    )

    return ordered_keys


def main():
    rules, updates = get_orders_and_updates()

    # part 1
    count = 0
    for update in updates:
        if validate_rules(update, rules):
            count += get_middle_number(update)
    print("Summed updates: %d" % count)

    # part 2
    count = 0
    for update in updates:
        if not validate_rules(update, rules):
            new_update = fix_with_rules(update, rules)
            count += get_middle_number(new_update)
    print("Summ fixed updates: %d" % count)


if __name__ == "__main__":
    main()