# --- Day 1: Trebuchet?! ---

# Something is wrong with global snow production, and you've been selected to
# take a look. The Elves have even given you a map; on it, they've used stars to
# mark the top fifty locations that are likely to be having problems.

# You've been doing this long enough to know that to restore snow operations,
# you need to check all fifty stars by December 25th.

# Collect stars by solving puzzles. Two puzzles will be made available on each
# day in the Advent calendar; the second puzzle is unlocked when you complete
# the first. Each puzzle grants one star. Good luck!

# You try to ask why they can't just use a weather machine ("not powerful
# enough") and where they're even sending you ("the sky") and why your map looks
# mostly blank ("you sure ask a lot of questions") and hang on did you just say
# the sky ("of course, where do you think snow comes from") when you realize
# that the Elves are already loading you into a trebuchet ("please hold still,
# we need to strap you in").

# As they're making the final adjustments, they discover that their calibration
# document (your puzzle input) has been amended by a very young Elf who was
# apparently just excited to show off her art skills. Consequently, the Elves
# are having trouble reading the values on the document.

# The newly-improved calibration document consists of lines of text; each line
# originally contained a specific calibration value that the Elves now need to
# recover. On each line, the calibration value can be found by combining the
# first digit and the last digit (in that order) to form a single two-digit
# number.

# For example:

# 1abc2
# pqr3stu8vwx
# a1b2c3d4e5f
# treb7uchet

# In this example, the calibration values of these four lines are 12, 38, 15,
# and 77. Adding these together produces 142.

# Consider your entire calibration document. What is the sum of all of the
# calibration values?

with open("files/P1.txt") as f:
    calibration = [line for line in f.read().strip().split()]


def part_1():
    total = 0
    for value in calibration:
        digits = [c for c in value if c.isdigit()]
        if digits:
            total += int(digits[0] + digits[-1])
    print(f"The sum of all calibration values is {total}")


# --- Part Two ---

# Your calculation isn't quite right. It looks like some of the digits are
# actually spelled out with letters: one, two, three, four, five, six, seven,
# eight, and nine also count as valid "digits".

# Equipped with this new information, you now need to find the real first and
# last digit on each line. For example:

# two1nine
# eightwothree
# abcone2threexyz
# xtwone3four
# 4nineeightseven2
# zoneight234
# 7pqrstsixteen

# In this example, the calibration values are 29, 83, 13, 24, 42, 14, and 76.
# Adding these together produces 281.

# What is the sum of all of the calibration values?

import re

words_to_numbers = {
    "one": "1",
    "two": "2",
    "three": "3",
    "four": "4",
    "five": "5",
    "six": "6",
    "seven": "7",
    "eight": "8",
    "nine": "9",
}


def is_letter(char):
    return "a" <= char <= "z"


def extraction(value):
    word = ""
    digits = []
    for c in value:
        if c.isdigit():
            digits.append(c)
            word = ""
        elif is_letter(c):
            word += c
            for w in words_to_numbers:
                if w in word:
                    m = re.search(w, word)
                    if m:
                        val = m.group(0)
                        digits.append(words_to_numbers[str(val)])
                        # keep last letter!
                        word = c
                        break
    return digits


def part_2():
    total = 0
    for value in calibration:
        digits = extraction(value)
        total += int(digits[0] + digits[-1])
    print(f"The sum of all calibration values is {total}")


if __name__ == "__main__":
    part_1()
    part_2()