main.yml

---
- name: Split input into separate rucksacks
  ansible.builtin.set_fact:
    rucksacks: "{{ day3_input | trim | split('\n') }}"

- name: Split the rucksacks into two halves
  tags: part1
  ansible.builtin.set_fact:
    rucksack_compartments: "{{ rucksack_compartments | default([]) + [[first_half, second_half]] }}"
  vars:
    half_len: "{{ (item | length | int / 2) | int }}"
    regex_first_half: "{{ '^' + ('.' * half_len | int) }}"
    regex_second_half: "{{ ('.' * half_len | int) + '$' }}"
    first_half: "{{ item | regex_replace(regex_second_half, '') }}"
    second_half: "{{ item | regex_replace(regex_first_half, '') }}"
  loop: "{{ rucksacks }}"

- name: Get character that occurs in both halves
  tags: part1
  ansible.builtin.set_fact:
    rucksack_characters: "{{ rucksack_characters | default([]) + [item.0 | list | intersect(item.1 | list) | first] }}"
  loop: "{{ rucksack_compartments }}"

- name: Return the characters
  tags: part1
  ansible.builtin.debug:
    msg: "{{ rucksack_characters | join('') }}"

- name: Loop through all letters in the alphabet and set their priorities
  ansible.builtin.set_fact:
    rucksack_priorities: "{{ rucksack_priorities | default({}) | combine({item: index + 1}) }}"
  loop: "{{ 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' | list }}"
  loop_control:
    index_var: index

- name: Get the total priorities of all double letters
  tags: part1
  ansible.builtin.set_fact:
    rucksack_total_priorities: "{{ rucksack_total_priorities | default(0) | int + rucksack_priorities[item] | int }}"
  loop: "{{ rucksack_characters }}"

- name: ANSWER TO PART 1 | Return the total priorities of all double letters
  tags: part1
  ansible.builtin.debug:
    msg: "{{ rucksack_total_priorities }}"

- name: Split the elves into groups of three
  tags: part2
  ansible.builtin.set_fact:
    rucksack_groups: "{{ rucksack_groups | default([]) + [item] }}"
  loop: "{{ rucksacks | list | batch(3) }}"

- name: Get letter that occurs in all three elves
  tags: part2
  ansible.builtin.set_fact:
    rucksack_characters: "{{ rucksack_characters | default([]) + [item.0 | list | intersect(item.1 | list) | intersect(item.2 | list) | first] }}"
  loop: "{{ rucksack_groups }}"

- name: Return the characters from each group
  tags: part2
  ansible.builtin.debug:
    msg: "{{ rucksack_characters | join('') }}"

- name: Get the total priorities of all triple letters
  tags: part2
  ansible.builtin.set_fact:
    rucksack_total_priorities: "{{ rucksack_total_priorities | default(0) | int + rucksack_priorities[item] | int }}"
  loop: "{{ rucksack_characters }}"

- name: ANSWER TO PART 2 | Return the total priorities of all triple letters
  tags: part2
  ansible.builtin.debug:
    msg: "{{ rucksack_total_priorities }}"