---
- name: build ping_map
  hosts: localhost
  become: no
  gather_facts: false

  tasks:

  - name: build ping_map
    ansible.builtin.set_fact:
      _ping_map: "{{ _ping_map | default({}) | combine ({entry: []}, recursive=True) }}"
    loop: "{{ inventory_hosts }}"
    loop_control:
      loop_var: entry
    vars:
      inventory_hosts: "{{ hostvars[inventory_hostname]['groups']['all'] }}"

  # - ansible.builtin.debug:
  #     msg:
  #       - "{{ _ping_map }}"

  - name: populate ping_map
    ansible.builtin.set_fact:
      _ping_map: "{{ _ping_map | default({}) | combine ({source: destination_list_append}, recursive=True) }}"
    loop: "{{ target_hosts|product(target_hosts) }}"
    loop_control:
      loop_var: entry
    vars:
      target_hosts: "{{ hostvars[inventory_hostname]['groups']['all'] }}"
      source: "{{ entry[0] }}"
      destination: "{{ entry[1] }}"
      destination_list: "{{ _ping_map[source] }}"
      destination_list_append: "{{ destination_list + [destination] }}"
    when: not entry[0] == entry[1]

  # - ansible.builtin.debug:
  #     msg:
  #       - "{{ _ping_map }}"

  - name: write global ping_map
    ansible.builtin.set_fact:
      _global_ping_map: "{{ _ping_map }}"
    delegate_to: localhost
    delegate_facts: true

- name: ping test
  hosts: all
  become: yes
  gather_facts: True

  tasks:

  - name: load global ping_map
    ansible.builtin.set_fact:
      _ping_map: "{{ hostvars['localhost']['_global_ping_map'] }}"
    when:
      - hostvars['localhost']['_global_ping_map'] is defined

  # - debug:
  #     msg:
  #       - "{{ _ping_map }}"

  - name: ping neighbours
    ansible.builtin.shell: |
      echo SOURCE {{ inventory_hostname }}
      echo DESTINATION {{ destination_target }}
      echo
      ping -Rn -c 1 {{ destination_ip }}
    loop: "{{ destination_targets }}"
    loop_control:
      loop_var: entry
    vars:
      destination_targets: "{{ _ping_map[inventory_hostname] }}"
      destination_target: "{{ entry }}"
      destination_ip: "{{ hostvars[destination_target]['ansible_default_ipv4']['address'] }}"
      source: "{{ inventory_hostname }}"
    register: _ping_results

  - name: print results
    ansible.builtin.debug:
      msg:
        - "{{ output }}"
    loop: "{{ _ping_results['results'] }}"
    loop_control:
      loop_var: idx
      label: "{{ destination }}"
    vars:
      destination: "{{ idx['entry'] }}"
      output: "{{ idx['stdout_lines'] }}"