#!/usr/bin/env python

# https://adventofcode.com/2025/day/12

import re


def prep_data(filename):
  shape_re = re.compile(r"\d:")
  region_re = re.compile(r"\d+x\d+:")
  shapes, regions, quantities = {}, [], []

  f = open(filename, "r")
  lines = [l.rstrip("\n") for l in f.readlines()]
  f.close()

  while lines != []:
    line = lines.pop(0)

    # shape
    if shape_re.match(line):
      tmp = []
      # read shape lines
      while True:
        l = lines.pop(0)
        if l == "":
          break
        else: 
          tmp.append(l)

      # parse shape
      shape = []
      for i in range(len(tmp)):
        for j in range(len(tmp[0])):
          if tmp[i][j] == "#":
            shape.append((i, j))
      shapes["shape-" + line[:-1]] = shape
      
    # region & quantities
    elif region_re.match(line):
      tmp = line.split(" ")
      regions.append(list(map(int, tmp.pop(0)[:-1].split("x"))))
      quantities.append(list(map(int, tmp)))

  return shapes, regions, quantities    


def solve_part_1() -> int:
  shapes, regions, quantities = prep_data("day12input.txt")
  areas = [len(shape) for shape in shapes]

  solvable, unsolvable, dont_know = 0, 0, 0

  # loop over problems
  for i in range(len(regions)):
    board = regions[i]
    quantity = quantities[i]
    
    # simple solvability check
    if board[0] * board[1] < sum(list(map(lambda a, q: a * q, areas, quantity))):
      print(f"Problem {i} is unsolvable")
      unsolvable += 1

    # check if a tileset of 3x3 squares would fit in theory
    elif (board[0] // 3) * (board[1] // 3) >= sum(quantity):
      print(f"Problem {i} is solvable")
      solvable += 1 
      
    else:
      print(f"don't know about problem {i}")
      dont_know += 1

  print(f"{solvable=}")
  print(f"{unsolvable=}")
  print(f"{dont_know=}")
  return solvable


# solve part 1
print(solve_part_1())