main.yml

---
- name: Split input into all pairs
  ansible.builtin.set_fact:
    pairs: "{{ day4_input | trim | split('\n') }}"

- name: Split pairs into the two assignments
  ansible.builtin.set_fact:
    assignments: "{{ assignments | default([]) + [item | split(',')] }}"
  loop: "{{ pairs }}"

- name: Split assignments into the four numbers
  ansible.builtin.set_fact:
    assignments_ranges: "{{ assignments_ranges | default([]) + [[item.0 | split('-'), item.1 | split('-')]] }}"
  loop: "{{ assignments }}"

- name: Get all numbers contained within assignment
  ansible.builtin.set_fact:
    assignment_nums: "{{ assignment_nums | default([]) + [[assignment_1 | split(',') | map('int'), assignment_2 | split(',') | map('int')]] }}"
  vars:
    assignment_1: "{% for i in range(item[0][0] | int, item[0][1] | int + 1) %}{{ i }}{% if i | int != item[0][1] | int %},{% endif %}{% endfor %}"
    assignment_2: "{% for i in range(item[1][0] | int, item[1][1] | int + 1) %}{{ i }}{% if i | int != item[1][1] | int %},{% endif %}{% endfor %}"
  loop: "{{ assignments_ranges }}"

- name: Add numbers to list if they fully overlap with another assignment
  tags: part1
  ansible.builtin.set_fact:
    overlap: "{{ overlap | default([]) + [intersect] }}"
  vars:
    intersect: "{{ item.0 | intersect(item.1) }}"
    fully_in_1: "{% if item.0 | length == item.0 | intersect(intersect) | length %}true{% else %}false{% endif %}"
    fully_in_2: "{% if item.1 | length == item.1 | intersect(intersect) | length %}true{% else %}false{% endif %}"
    result: "{% if fully_in_1 == 'true' or fully_in_2 == 'true' %}true{% else %}false{% endif %}"
  when: result == 'true'
  loop: "{{ assignment_nums }}"

- name: ANSWER TO PART 1 | Get the total number of overlapping numbers
  tags: part1
  ansible.builtin.debug:
    msg: "{{ overlap | length }}"

- name: Add numbers to list if they overlap at all
  tags: part2
  ansible.builtin.set_fact:
    overlap_2: "{{ overlap_2 | default([]) + [item] }}"
  vars:
    result: "{% if item.0 | intersect(item.1) | length > 0 %}true{% else %}false{% endif %}"
  when: result == 'true'
  loop: "{{ assignment_nums }}"

- name: ANSWER TO PART 2 | Get the total number of numbers that overlap at all
  tags: part2
  ansible.builtin.debug:
    msg: "{{ overlap_2 | length }}"