day 04

Mix.install([
  {:kino, "~> 0.12.2"}
])

Section

input = Kino.Input.textarea("paste")

example = Kino.Input.textarea("paste")

Part 01

defmodule PassportValidator do
  def is_valid?(passport) do
    validate_fields(Map.keys(passport)) and
      [
        validate_byr(passport.byr),
        validate_iyr(passport.iyr),
        validate_eyr(passport.eyr),
        validate_hgt(passport.hgt),
        validate_hcl(passport.hcl),
        validate_ecl(passport.ecl),
        validate_pid(passport.pid)
      ]
      |> Enum.all?()
  end

  defp validate_fields(keys) do
    ([
       :hcl,
       :pid,
       :ecl,
       :hgt,
       :eyr,
       :iyr,
       :byr
     ] -- keys)
    |> Enum.empty?()
  end

  defp validate_pid(pid) do
    Regex.match?(~r/^[0-9]{9}$/, pid)
  end

  defp validate_ecl(ecl) do
    Regex.match?(~r/amb|blu|brn|gry|grn|hzl|oth/, ecl)
  end

  defp validate_hcl(hcl) do
    Regex.match?(~r/#([0-9]|[a-f]){6}$/, hcl)
  end

  defp validate_hgt(hgt) do
    case String.split(hgt, ~r/(in|cm)/, include_captures: true, trim: true) do
      [number, "cm"] -> String.to_integer(number) >= 150 and String.to_integer(number) <= 193
      [number, "in"] -> String.to_integer(number) >= 59 and String.to_integer(number) <= 76
      _ -> false
    end
  end

  defp validate_eyr(eyr) do
    String.to_integer(eyr) >= 2020 and String.to_integer(eyr) <= 2030
  end

  defp validate_iyr(iyr) do
    String.to_integer(iyr) >= 2010 and String.to_integer(iyr) <= 2020
  end

  defp validate_byr(byr) do
    String.to_integer(byr) >= 1920 and String.to_integer(byr) <= 2002
  end
end

lines =
  input
  |> Kino.Input.read()
  |> String.split("\n\n", trim: true)
  |> Enum.filter(fn passport ->
    Regex.scan(~r/(byr|iyr|eyr|hgt|hcl|ecl|pid)/, passport) |> Enum.count() == 7
  end)
  |> Enum.count()

Part 02

input
|> Kino.Input.read()
|> String.split("\n\n", trim: true)
|> Enum.map(fn passport ->
  passport
  |> String.split("\n")
  |> Enum.reduce(%{}, fn line, acc ->
    String.split(line, " ", trim: true)
    |> Enum.reduce(acc, fn fields, acc ->
      [key, value] = String.split(fields, ":", trim: true)
      Map.put(acc, String.to_atom(key), value)
    end)
  end)
end)
|> Enum.filter(fn passport ->
  PassportValidator.is_valid?(passport)
end)
|> Enum.count()