#!/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

import re


def parse_lock(block: list) -> list:
    lock = [0] * 5
    for y, _ in enumerate(block):
        pins = re.finditer(r"#", block[y])
        for p in pins:
            lock[p.start()] = y

    return lock


def parse_key(block: list) -> list:
    key = [0] * 5
    for y, _ in enumerate(block):
        pins = re.finditer(r"\.", block[y])
        for p in pins:
            key[p.start()] = len(block) - 2 - y

    return key


def readinput():
    with open("input", "r", encoding="utf-8") as file:
        schematics = []
        current_schematic = []

        for line in file:
            line = line.rstrip()
            if line:
                current_schematic.append(line)
            else:
                schematics.append(current_schematic)
                current_schematic = []

        schematics.append(current_schematic)

    keys = []
    locks = []
    for schematic in schematics:
        if schematic[0] == "#####":
            locks.append(parse_lock(schematic))
        else:
            keys.append(parse_key(schematic))

    return keys, locks


def key_fits_lock(key: list, lock: list) -> bool:
    for k, l in zip(key, lock):
        if k + l >= 6:
            return False
    return True


def main():
    keys, locks = readinput()

    # part 1
    fitting = 0
    for key in keys:
        for lock in locks:
            if key_fits_lock(key, lock):
                fitting += 1

    print("Fitting keys: %d" % fitting)


if __name__ == "__main__":
    main()