main.yml

---
- name: Loop over every character for 4 characters
  tags: part1
  ansible.builtin.set_fact:
    packet_pos: "{{ item + 1 }}"
  vars:
    prev_4: "{{ [day6_input[item - 3], day6_input[item - 2], day6_input[item - 1], day6_input[item]] }}"
  when: packet_pos is not defined and prev_4 | unique | length == 4
  loop: "{{ range(3, day6_input | trim | length) | list }}"

- name: ANSWER TO PART 1 | Return the position of the packet
  tags: part1
  ansible.builtin.debug:
    msg: "{{ packet_pos }}"

- name: Loop over every character for 14 characters
  tags: part2
  ansible.builtin.set_fact:
    msg_pos: "{{ item + 1 }}"
  vars:
    # not gonna bother making this prettier tbh
    prev_14: "{{ [day6_input[item - 13], day6_input[item - 12], day6_input[item - 11], day6_input[item - 10], day6_input[item - 9], day6_input[item - 8], day6_input[item - 7], day6_input[item - 6], day6_input[item - 5], day6_input[item - 4], day6_input[item - 3], day6_input[item - 2], day6_input[item - 1], day6_input[item]] }}"
  when: msg_pos is not defined and prev_14 | unique | length == 14
  loop: "{{ range(3, day6_input | trim | length) | list }}"

- name: ANSWER TO PART 2 | Return the position of the message
  tags: part2
  ansible.builtin.debug:
    msg: "{{ msg_pos }}"

...