# ptsd_reacquire_attempt.yml — DHCP reacquire verification + CASE A cleanup (standalone)
# Purpose:
#   1) Re-run Phase 0 connectivity to DEV2 (same logic as main playbook)
#   2) Verify migrated DHCP state:
#        - ppp0 is absent
#        - eth0.4000 exists AND has IPv4
#   3) If CASE A confirmed (DHCP ok, no PPP), perform minimal cleanup step:
#        - detect pending reboot process; if found, kill it
#      Maintain cumulative cleanup report and print at end.
#
# Notes:
#   - Does NOT respect /tmp/ptsd.inprogress (verification runs while migration is in progress).
#   - Does NOT do DEV1 teardown cleanup here (no tunnel/IP removal); this is intentional.

- name: "PTSD DHCP Reacquire Attempt | Phase 0 | Connectivity + wrapper + DHCP state check + CASE A cleanup"
  hosts: all
  gather_facts: no

  vars:
    pathprefix: "PATH=/sbin:/usr/sbin:/bin:/usr/bin:$PATH; "

    dev1_user: "root"
    dev1_pass: "wavewave"

    dev2_host: "192.168.1.1"
    dev2_port: 22

    dev2_side_ip: "192.168.1.11/24"
    dev2_side_ip_addr: "{{ dev2_side_ip.split('/')[0] }}"
    dev1_iface: "br-wan"

    arping_iface: "eth0"

    dev2_ssh_user: "root"
    dev2_passfiles:
      - "basicpass"
      - "basicpass2"

    ssh_opts_common: >-
      -o PreferredAuthentications=password
      -o PubkeyAuthentication=no
      -o StrictHostKeyChecking=no
      -o UserKnownHostsFile=/dev/null
      -o NumberOfPasswordPrompts=1
      -o ConnectTimeout=30
      -o ConnectionAttempts=1
      -o LogLevel=ERROR

    debugging: true
    ssh_timeout: 30

  pre_tasks:
    - name: Initialize passfile facts defensively (avoid undefined vars later)
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_passfile_used_direct: "NONE"
        dev2_passfile_used_tunnel: "NONE"
        dev2_passfile_used_lldp4: "NONE"
        dev2_passfile_used_lldp6: "NONE"
      changed_when: false

    - name: Read DEV1 hostname (busybox-safe)
      ansible.builtin.raw: >
        {{ pathprefix }}
        (cat /proc/sys/kernel/hostname 2>/dev/null || echo "")
      register: dev1_host_read
      changed_when: false

    - name: Stop early if connected DEV1 hostname != inventory (guard)
      ansible.builtin.meta: end_host
      when: (dev1_host_read.stdout | trim | length > 0) and
            ((dev1_host_read.stdout | trim) != (inventory_hostname | string))

  tasks:
    # ============================ PHASE 0: LLDP DISCOVERY (IPv4 + IPv6) ============================
    - name: Compute hostname digits key for LLDP lookup (DEV2)
      ansible.builtin.set_fact:
        dev2_lldp_digits: "{{ (inventory_hostname | string) | regex_replace('[^0-9]', '') }}"
      changed_when: false

    - name: Discover DEV2 candidate IPv4 via LLDP on DEV1 (best-effort)
      ansible.builtin.raw: >
        {{ pathprefix }}
        DIGITS="{{ dev2_lldp_digits }}";
        cat /var/run/lldp_server.json 2>/dev/null \
          | grep "${DIGITS}" -A 10 \
          | grep address \
          | grep -vE 'subtype|ipv6' \
          | awk -F'"' '{ print $4 }' \
          | head -n1
      register: dev2_lldp_ip_raw
      changed_when: false
      failed_when: false

    - name: Discover DEV2 candidate IPv6 via LLDP on DEV1 (best-effort)
      ansible.builtin.raw: >
        {{ pathprefix }}
        DIGITS="{{ dev2_lldp_digits }}";
        cat /var/run/lldp_server.json 2>/dev/null \
          | grep "${DIGITS}" -A 15 \
          | grep 'address_ipv6' \
          | awk -F'"' '{ print $4 }' \
          | head -n1
      register: dev2_lldp_ip6_raw
      changed_when: false
      failed_when: false

    - name: Capture LLDP-derived DEV2 IP facts
      ansible.builtin.set_fact:
        lldp_dev2_ip: "{{ (dev2_lldp_ip_raw.stdout | default('')) | trim }}"
        lldp_dev2_ip6: "{{ (dev2_lldp_ip6_raw.stdout | default('')) | trim }}"
      changed_when: false

    - name: Classify LLDP IPv4 candidate
      delegate_to: localhost
      ansible.builtin.set_fact:
        lldp_ip_class: >-
          {% set ip = (lldp_dev2_ip | default('')) %}
          {% if ip == '' %}none
          {% elif ip.startswith('10.') %}10
          {% elif ip.startswith('192.168.') %}192_168
          {% else %}other{% endif %}
      changed_when: false

    - name: Debug LLDP candidates
      when: debugging | bool
      delegate_to: localhost
      ansible.builtin.debug:
        msg:
          - "LLDP digits={{ dev2_lldp_digits | default('') }}"
          - "LLDP IPv4 candidate={{ lldp_dev2_ip | default('<none>') }}"
          - "LLDP IPv4 class={{ lldp_ip_class | default('none') }}"
          - "LLDP IPv6 candidate={{ lldp_dev2_ip6 | default('<none>') }}"

    # ============================ PHASE 0: PRIMARY PATH DECISION ============================
    - name: Override dev2_host from LLDP when candidate is 192.168.x.x
      when: (lldp_ip_class | trim) == "192_168" and (lldp_dev2_ip | trim | length > 0)
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_host: "{{ lldp_dev2_ip | trim }}"
      changed_when: false

    - name: Set connection method initial (direct_lldp if 10.x else tunnel)
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_conn_method: "{{ 'direct_lldp' if ((lldp_ip_class | trim) == '10') else 'tunnel' }}"
      changed_when: false

    # ============================ PHASE 0: DIRECT LLDP IPv4 AUTH (10.x) ============================
    - name: Try DEV2 login via direct LLDP IPv4 (10.x) with basicpass
      when: dev2_conn_method == "direct_lldp"
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        HOST="{{ lldp_dev2_ip }}"
        sshpass -f basicpass ssh {{ ssh_opts_common }} \
          -o AddressFamily=inet \
          "{{ dev2_ssh_user }}@${HOST}" echo OK >/dev/null 2>&1
      args: { executable: /bin/bash }
      register: dev2_lldp_try_basicpass
      changed_when: false
      ignore_errors: true

    - name: Select basicpass for direct LLDP if succeeded
      when: dev2_conn_method == "direct_lldp" and dev2_lldp_try_basicpass.rc == 0
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_passfile_used_direct: "basicpass"
      changed_when: false

    - name: Try DEV2 login via direct LLDP IPv4 (10.x) with basicpass2 (only if first failed)
      when: dev2_conn_method == "direct_lldp" and (dev2_passfile_used_direct == "NONE")
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        HOST="{{ lldp_dev2_ip }}"
        sshpass -f basicpass2 ssh {{ ssh_opts_common }} \
          -o AddressFamily=inet \
          "{{ dev2_ssh_user }}@${HOST}" echo OK >/dev/null 2>&1
      args: { executable: /bin/bash }
      register: dev2_lldp_try_basicpass2
      changed_when: false
      ignore_errors: true

    - name: Select basicpass2 for direct LLDP if succeeded
      when: dev2_conn_method == "direct_lldp" and dev2_passfile_used_direct == "NONE" and dev2_lldp_try_basicpass2.rc == 0
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_passfile_used_direct: "basicpass2"
      changed_when: false

    # ============================ PHASE 0: TUNNEL PREP (DEV1 temp IP + ARP + tunnel) ============================
    - name: Add temporary IP on DEV1 (tolerate 'File exists')
      when: dev2_conn_method == "tunnel"
      ansible.builtin.raw: >
        {{ pathprefix }}
        ip a add {{ dev2_side_ip }} dev {{ dev1_iface }}
      register: add_ip
      changed_when: add_ip.rc == 0
      failed_when: >
        add_ip.rc != 0
        and ('File exists' not in (add_ip.stdout | default('')))
        and ('File exists' not in (add_ip.stderr | default('')))

    - name: Discover DEV2 MAC via bridge fdb on DEV1 (best-effort)
      when: dev2_conn_method == "tunnel"
      ansible.builtin.raw: >
        {{ pathprefix }}
        bridge fdb show {{ dev1_iface }} | grep eth0 | grep -v permanent | grep master | awk '{print $1}' | head -n1
      register: dev2_mac_scan
      changed_when: false
      failed_when: false

    - name: Capture discovered DEV2 MAC (if any)
      when: dev2_conn_method == "tunnel"
      ansible.builtin.set_fact:
        dev2_mac: "{{ (dev2_mac_scan.stdout | default('') ) | trim }}"
      changed_when: false

    - name: Clear existing ARP entry for DEV2 on DEV1 (best-effort)
      when: dev2_conn_method == "tunnel"
      ansible.builtin.raw: >
        {{ pathprefix }}
        ip neigh del {{ dev2_host }} dev {{ dev1_iface }} 2>/dev/null || true
      changed_when: false
      failed_when: false

    - name: Add static ARP entry on DEV1 (if MAC discovered; tolerate 'File exists')
      when: dev2_conn_method == "tunnel" and (dev2_mac | default('') | length > 0)
      ansible.builtin.raw: >
        {{ pathprefix }}
        ip neigh add {{ dev2_host }} lladdr {{ dev2_mac }} dev {{ dev1_iface }} nud permanent
      register: dev2_arp_add
      changed_when: dev2_arp_add.rc == 0
      failed_when: >
        dev2_arp_add.rc != 0
        and ('File exists' not in (dev2_arp_add.stdout | default('')))
        and ('File exists' not in (dev2_arp_add.stderr | default('')))

    - name: Refresh ARP (best-effort)
      when: dev2_conn_method == "tunnel"
      ansible.builtin.raw: >
        {{ pathprefix }}
        arping -U -I {{ arping_iface }} {{ dev2_side_ip_addr }} -c 3
      changed_when: false
      failed_when: false

    - name: Pick a free local TCP port for the tunnel (controller side)
      when: dev2_conn_method == "tunnel"
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        pick() {
          for i in $(seq 1 25); do
            p="$(shuf -i 20000-39999 -n 1)"
            if command -v ss >/dev/null 2>&1; then
              if ! ss -ltn | awk '{print $4}' | grep -qE "(:|\.)${p}$"; then
                echo "$p"; return 0
              fi
            else
              if ! nc -z 127.0.0.1 "$p" >/dev/null 2>&1; then
                echo "$p"; return 0
              fi
            fi
          done
          return 1
        }
        pick
      args: { executable: /bin/bash }
      register: pick_port
      changed_when: false

    - name: Stop if no free local port was found
      when: dev2_conn_method == "tunnel" and (pick_port.stdout | trim | length) == 0
      ansible.builtin.meta: end_host

    - name: Create control dir for SSH ControlMaster
      when: dev2_conn_method == "tunnel"
      delegate_to: localhost
      ansible.builtin.shell: "mktemp -d"
      args: { executable: /bin/bash }
      register: mktemp_dir
      changed_when: false

    - name: Record chosen local port and build ControlMaster socket path
      when: dev2_conn_method == "tunnel"
      delegate_to: localhost
      ansible.builtin.set_fact:
        _local_port: "{{ pick_port.stdout | trim }}"
        _ctrl_dir: "{{ mktemp_dir.stdout | trim }}"
        _ctrl_sock: "{{ (mktemp_dir.stdout | trim) }}/ssh_tunnel_ctl"
      changed_when: false

    - name: Start SSH ControlMaster and forward 127.0.0.1:local_port → DEV2:22 via DEV1
      when: dev2_conn_method == "tunnel"
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        USER="{{ dev1_user }}"
        HOST="{{ ansible_host | default(inventory_hostname) }}"
        sshpass -p '{{ dev1_pass }}' ssh -f -N {{ ssh_opts_common }} \
          -M -S "{{ _ctrl_sock }}" \
          -L "127.0.0.1:{{ _local_port }}:{{ dev2_host }}:{{ dev2_port }}" \
          "${USER}@${HOST}"
      args: { executable: /bin/bash }
      register: start_tunnel
      changed_when: true

    - name: Probe TCP reachability to DEV2 through the tunnel (nc)
      when: dev2_conn_method == "tunnel"
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        nc -z -w5 127.0.0.1 "{{ _local_port }}"
      args: { executable: /bin/bash }
      register: nc_probe
      changed_when: false
      ignore_errors: true

    - name: Stop if tunnel TCP probe failed
      when: dev2_conn_method == "tunnel" and nc_probe.rc != 0
      ansible.builtin.meta: end_host

    - name: Pick DEV2 password for root (tunnel) try basicpass
      when: dev2_conn_method == "tunnel"
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        PORT="{{ _local_port }}"
        sshpass -f basicpass ssh {{ ssh_opts_common }} \
          -o AddressFamily=inet \
          -p "$PORT" root@127.0.0.1 echo OK >/dev/null 2>&1
      args: { executable: /bin/bash }
      register: dev2_try_basicpass
      changed_when: false
      ignore_errors: true

    - name: Select basicpass if tunnel login succeeded
      when: dev2_conn_method == "tunnel" and dev2_try_basicpass.rc == 0
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_passfile_used_tunnel: "basicpass"
      changed_when: false

    - name: Try DEV2 login through tunnel with basicpass2 (only if first failed)
      when: dev2_conn_method == "tunnel" and (dev2_passfile_used_tunnel == "NONE")
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        PORT="{{ _local_port }}"
        sshpass -f basicpass2 ssh {{ ssh_opts_common }} \
          -o AddressFamily=inet \
          -p "$PORT" root@127.0.0.1 echo OK >/dev/null 2>&1
      args: { executable: /bin/bash }
      register: dev2_try_basicpass2
      changed_when: false
      ignore_errors: true

    - name: Select basicpass2 if tunnel login succeeded
      when: dev2_conn_method == "tunnel" and dev2_passfile_used_tunnel == "NONE" and dev2_try_basicpass2.rc == 0
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_passfile_used_tunnel: "basicpass2"
      changed_when: false

    # ============================ PHASE 0: SAFETY GUARD (MAC CHECK) ============================
    - name: Read remote eth0 MAC via tunnel (guard, sanitized)
      when:
        - dev2_conn_method == "tunnel"
        - (dev2_passfile_used_tunnel | default('NONE')) != "NONE"
        - (dev2_mac | default('') | length) > 0
      delegate_to: localhost
      ansible.builtin.shell: |
        PORT="{{ _local_port }}"
        sshpass -f "{{ dev2_passfile_used_tunnel }}" ssh {{ ssh_opts_common }} \
          -p "$PORT" "{{ dev2_ssh_user }}@127.0.0.1" \
          "cat /sys/class/net/eth0/address 2>/dev/null || ip link show eth0 2>/dev/null" 2>&1
      args: { executable: /bin/bash }
      register: dev2_eth0_mac_raw
      changed_when: false
      failed_when: false

    - name: Normalize remote eth0 MAC (extract last MAC-like token)
      when:
        - dev2_conn_method == "tunnel"
        - (dev2_passfile_used_tunnel | default('NONE')) != "NONE"
        - (dev2_mac | default('') | length) > 0
      delegate_to: localhost
      ansible.builtin.set_fact:
        remote_eth0_mac: >-
          {{
            (
              (dev2_eth0_mac_raw.stdout | default('') | regex_replace('\r','')) ~ "\n" ~
              (dev2_eth0_mac_raw.stderr | default('') | regex_replace('\r',''))
            )
            | regex_findall('([0-9a-fA-F]{2}(?::[0-9a-fA-F]{2}){5})')
            | last
            | default('')
            | lower
          }}
      changed_when: false

    - name: Abort if remote eth0 MAC != discovered DEV2 MAC
      when:
        - dev2_conn_method == "tunnel"
        - (dev2_passfile_used_tunnel | default('NONE')) != "NONE"
        - (dev2_mac | default('') | length) > 0
        - (remote_eth0_mac | default('') | length) > 0
        - (remote_eth0_mac | lower) != (dev2_mac | lower)
      ansible.builtin.fail:
        msg: >-
          Safety stop: tunnel reached wrong device.
          expected_dev2_mac={{ dev2_mac }}, remote_eth0_mac={{ remote_eth0_mac }}

    # ============================ PHASE 0: FALLBACKS (only if tunnel auth failed) ============================
    - name: Try DEV2 login via LLDP IPv4 10.x (fallback if tunnel auth failed)
      when:
        - dev2_conn_method == "tunnel"
        - dev2_passfile_used_tunnel == "NONE"
        - (lldp_dev2_ip | default('')) is match('^10\\.')
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        HOST="{{ lldp_dev2_ip }}"
        for f in {{ dev2_passfiles | join(' ') }}; do
          if timeout 20s sshpass -f "$f" ssh {{ ssh_opts_common }} \
              -o AddressFamily=inet \
              -o ConnectTimeout=10 \
              "{{ dev2_ssh_user }}@${HOST}" echo OK >/dev/null 2>&1; then
            echo "$f"; exit 0
          fi
        done
        echo "NONE"; exit 1
      args: { executable: /bin/bash }
      register: dev2_auth_lldp4
      changed_when: false
      failed_when: false
      ignore_errors: true

    - name: Record LLDP IPv4 fallback decision
      when:
        - dev2_conn_method == "tunnel"
        - dev2_passfile_used_tunnel == "NONE"
        - (lldp_dev2_ip | default('')) is match('^10\\.')
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_passfile_used_lldp4: "{{ (dev2_auth_lldp4.rc == 0) | ternary((dev2_auth_lldp4.stdout | trim), 'NONE') }}"
      changed_when: false

    - name: Copy DEV2 passfiles to DEV1 for IPv6 nested SSH (last resort)
      when:
        - dev2_conn_method == "tunnel"
        - dev2_passfile_used_tunnel == "NONE"
        - dev2_passfile_used_lldp4 == "NONE"
        - (lldp_dev2_ip6 | default('') | length) > 0
      ansible.builtin.copy:
        src: "{{ item }}"
        dest: "/tmp/{{ item }}"
        mode: "0600"
      loop: "{{ dev2_passfiles }}"
      ignore_errors: true

    - name: Try DEV2 login via LLDP IPv6 (nested SSH through DEV1; last resort)
      when:
        - dev2_conn_method == "tunnel"
        - dev2_passfile_used_tunnel == "NONE"
        - dev2_passfile_used_lldp4 == "NONE"
        - (lldp_dev2_ip6 | default('') | length) > 0
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        IP6="{{ lldp_dev2_ip6 }}"
        for f in {{ dev2_passfiles | join(' ') }}; do
          if sshpass -p '{{ dev1_pass }}' ssh {{ ssh_opts_common }} \
              "{{ dev1_user }}@{{ ansible_host|default(inventory_hostname) }}" \
              "timeout {{ ssh_timeout }}s sshpass -f '/tmp/${f}' ssh \
                 -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=ERROR \
                 -o PubkeyAuthentication=no \
                 -o PreferredAuthentications=password -o NumberOfPasswordPrompts=1 \
                 -o ConnectTimeout={{ ssh_timeout }} \
                 '{{ dev2_ssh_user }}@\[${IP6}%{{ dev1_iface }}\]' 'echo OK' " \
              >/dev/null 2>&1; then
            echo "$f"; exit 0
          fi
        done
        echo "NONE"; exit 1
      args: { executable: /bin/bash }
      register: dev2_auth_lldp6
      changed_when: false
      failed_when: false
      ignore_errors: true

    - name: Record LLDP IPv6 fallback decision
      when:
        - dev2_conn_method == "tunnel"
        - dev2_passfile_used_tunnel == "NONE"
        - dev2_passfile_used_lldp4 == "NONE"
        - (lldp_dev2_ip6 | default('') | length) > 0
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_passfile_used_lldp6: "{{ (dev2_auth_lldp6.rc == 0) | ternary((dev2_auth_lldp6.stdout | trim), 'NONE') }}"
      changed_when: false

    # ============================ PHASE 0: FINAL DECISION + WRAPPER FACTS ============================
    - name: Decide final DEV2 connection mode (direct_lldp > tunnel > lldp4 > lldp6)
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_conn_final: >-
          {%- if dev2_conn_method == 'direct_lldp' and (dev2_passfile_used_direct | default('NONE')) != 'NONE' -%}
            direct_lldp
          {%- elif dev2_conn_method == 'tunnel' and (dev2_passfile_used_tunnel | default('NONE')) != 'NONE' -%}
            tunnel
          {%- elif (dev2_passfile_used_lldp4 | default('NONE')) != 'NONE' -%}
            lldp4_fallback
          {%- elif (dev2_passfile_used_lldp6 | default('NONE')) != 'NONE' -%}
            lldp6_via_dev1
          {%- else -%}
            none
          {%- endif -%}
      changed_when: false

    - name: Abort if all DEV2 connection methods failed
      when: dev2_conn_final == "none"
      ansible.builtin.fail:
        msg: >
          DEV2 unreachable: tunnel auth={{ dev2_passfile_used_tunnel | default('n/a') }},
          direct auth={{ dev2_passfile_used_direct | default('n/a') }},
          lldp4 auth={{ dev2_passfile_used_lldp4 | default('n/a') }},
          lldp6 auth={{ dev2_passfile_used_lldp6 | default('n/a') }}.

    - name: Debug final connectivity decision
      when: debugging | bool
      delegate_to: localhost
      ansible.builtin.debug:
        msg:
          - "dev2_conn_final={{ dev2_conn_final }}"
          - "tunnel passfile={{ dev2_passfile_used_tunnel | default('n/a') }}"
          - "direct passfile={{ dev2_passfile_used_direct | default('n/a') }}"
          - "lldp4 passfile={{ dev2_passfile_used_lldp4 | default('n/a') }}"
          - "lldp6 passfile={{ dev2_passfile_used_lldp6 | default('n/a') }}"
          - "tunnel target={{ dev2_host }}:{{ dev2_port }} (forwarded to 127.0.0.1:{{ _local_port | default('na') }})"
          - "lldp ipv4={{ lldp_dev2_ip | default('') }}"
          - "lldp ipv6={{ lldp_dev2_ip6 | default('') }}"

    - name: Build DEV2 exec wrapper (controller-side) for verification commands
      delegate_to: localhost
      ansible.builtin.set_fact:
        dev2_exec_cmd: |
          set -e
          MODE="{{ dev2_conn_final }}"
          if [ -z "${DEV2_CMD:-}" ]; then
            echo "ERROR: DEV2_CMD is empty" >&2
            exit 2
          fi

          case "$MODE" in
            tunnel)
              PORT="{{ _local_port | default('') }}"
              PASS="{{ dev2_passfile_used_tunnel }}"
              sshpass -f "$PASS" ssh {{ ssh_opts_common }} \
                -o AddressFamily=inet \
                -p "$PORT" "{{ dev2_ssh_user }}@127.0.0.1" \
                "{{ pathprefix }} ${DEV2_CMD}" 2>&1
              ;;
            direct_lldp)
              HOST="{{ lldp_dev2_ip }}"
              PASS="{{ dev2_passfile_used_direct }}"
              sshpass -f "$PASS" ssh {{ ssh_opts_common }} \
                -o AddressFamily=inet \
                "{{ dev2_ssh_user }}@${HOST}" \
                "{{ pathprefix }} ${DEV2_CMD}" 2>&1
              ;;
            lldp4_fallback)
              HOST="{{ lldp_dev2_ip }}"
              PASS="{{ dev2_passfile_used_lldp4 }}"
              sshpass -f "$PASS" ssh {{ ssh_opts_common }} \
                -o AddressFamily=inet \
                "{{ dev2_ssh_user }}@${HOST}" \
                "{{ pathprefix }} ${DEV2_CMD}" 2>&1
              ;;
            lldp6_via_dev1)
              IP6="{{ lldp_dev2_ip6 }}"
              F="{{ dev2_passfile_used_lldp6 }}"
              sshpass -p "{{ dev1_pass }}" ssh {{ ssh_opts_common }} \
                "{{ dev1_user }}@{{ ansible_host | default(inventory_hostname) }}" \
                "sshpass -f '/tmp/${F}' ssh \
                   -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=ERROR \
                   -o PubkeyAuthentication=no \
                   -o PreferredAuthentications=password -o NumberOfPasswordPrompts=1 \
                   -o ConnectTimeout={{ ssh_timeout }} \
                   '{{ dev2_ssh_user }}@\[${IP6}%{{ dev1_iface }}\]' \
                   '{{ pathprefix }} '"${DEV2_CMD}" 2>&1"
              ;;
            *)
              echo "ERROR: unknown MODE=$MODE" >&2
              exit 3
              ;;
          esac
      changed_when: false

    # ============================ VERIFY: DHCP MIGRATION STATE ============================
    - name: VERIFY | DEV2 check: ppp0 exists?
      delegate_to: localhost
      ansible.builtin.shell: |
        export DEV2_CMD="ip link show ppp0 >/dev/null 2>&1 && echo YES || echo NO"
        {{ dev2_exec_cmd }}
      args: { executable: /bin/bash }
      register: v_ppp0_exists
      changed_when: false
      failed_when: false

    - name: VERIFY | DEV2 check: eth0.4000 exists?
      delegate_to: localhost
      ansible.builtin.shell: |
        export DEV2_CMD="ip link show eth0.4000 >/dev/null 2>&1 && echo YES || echo NO"
        {{ dev2_exec_cmd }}
      args: { executable: /bin/bash }
      register: v_eth04000_exists
      changed_when: false
      failed_when: false

    - name: VERIFY | DEV2 check: eth0.4000 has IPv4?
      delegate_to: localhost
      ansible.builtin.shell: |
        export DEV2_CMD="ip -4 addr show dev eth0.4000 2>/dev/null | grep -m1 'inet ' >/dev/null 2>&1 && echo YES || echo NO"
        {{ dev2_exec_cmd }}
      args: { executable: /bin/bash }
      register: v_eth04000_has_ipv4
      changed_when: false
      failed_when: false

    - name: VERIFY | Summarize DHCP migration state
      delegate_to: localhost
      ansible.builtin.set_fact:
        ppp0_exists: "{{ (v_ppp0_exists.stdout | default('') | trim) == 'YES' }}"
        eth04000_exists: "{{ (v_eth04000_exists.stdout | default('') | trim) == 'YES' }}"
        eth04000_has_ipv4: "{{ (v_eth04000_has_ipv4.stdout | default('') | trim) == 'YES' }}"
        dhcp_migrated_ok: >-
          {{
            ((v_ppp0_exists.stdout | default('') | trim) != 'YES')
            and
            ((v_eth04000_exists.stdout | default('') | trim) == 'YES')
            and
            ((v_eth04000_has_ipv4.stdout | default('') | trim) == 'YES')
          }}
      changed_when: false

    - name: VERIFY | Result: DHCP migrated (SUCCESS) or not (graceful stop)
      delegate_to: localhost
      ansible.builtin.debug:
        msg:
          - "DHCP reacquire check via dev2_conn_final={{ dev2_conn_final }}"
          - "ppp0_exists={{ ppp0_exists }}"
          - "eth0.4000_exists={{ eth04000_exists }}"
          - "eth0.4000_has_ipv4={{ eth04000_has_ipv4 }}"
          - "dhcp_migrated_ok={{ dhcp_migrated_ok }}"
      changed_when: false

    - name: VERIFY | Graceful stop if DHCP migration state is not confirmed
      when: not (dhcp_migrated_ok | bool)
      delegate_to: localhost
      ansible.builtin.debug:
        msg:
          - "Graceful stop: DHCP migration state is not confirmed (not CASE A)."
          - "ppp0_exists={{ ppp0_exists }}"
          - "eth0.4000_exists={{ eth04000_exists }}"
          - "eth0.4000_has_ipv4={{ eth04000_has_ipv4 }}"
          - "dev2_conn_final={{ dev2_conn_final }}"
      changed_when: false

    - name: VERIFY | End host if DHCP migration state is not confirmed
      when: not (dhcp_migrated_ok | bool)
      ansible.builtin.meta: end_host

    # ============================ CASE A CLEANUP: CANCEL PENDING REBOOT ============================
    - name: CASE A | Initialize cumulative cleanup report
      when: dhcp_migrated_ok | bool
      delegate_to: localhost
      ansible.builtin.set_fact:
        cleanup_report: "case A observed"
      changed_when: false

    - name: "CASE A | DEV2 detect pending reboot processes (best-effort)"
      when: dhcp_migrated_ok | bool
      delegate_to: localhost
      ansible.builtin.shell: |
        # BusyBox-friendly: look for delayed reboot patterns.
        export DEV2_CMD="ps w 2>/dev/null | grep -E '[r]eboot( |$)|[n]ohup reboot' || true"
        {{ dev2_exec_cmd }}
      args: { executable: /bin/bash }
      register: reboot_ps
      changed_when: false
      failed_when: false

    - name: "CASE A | DEV2 cancel pending reboot if found (kill reboot PIDs)"
      when: dhcp_migrated_ok | bool
      delegate_to: localhost
      ansible.builtin.shell: |
        set -e
        # Extract PID from BusyBox ps output: assume PID is the first column.
        # Only target lines that clearly include "reboot" or "nohup reboot".
        PIDS="$(printf '%s\n' "{{ reboot_ps.stdout | default('') | regex_replace('\r','') }}" \
          | grep -E '(^| )reboot( |$)|nohup reboot' \
          | awk '{print $1}' \
          | grep -E '^[0-9]+$' \
          | sort -u || true)"

        if [ -z "$PIDS" ]; then
          echo "NONE"
          exit 0
        fi

        # Try TERM then KILL.
        for p in $PIDS; do
          kill "$p" 2>/dev/null || true
        done
        sleep 1
        for p in $PIDS; do
          kill -9 "$p" 2>/dev/null || true
        done

        echo "$PIDS"
      args: { executable: /bin/bash }
      register: reboot_kill
      changed_when: false
      failed_when: false

    - name: CASE A | Append reboot cancellation result to cleanup report
      when: dhcp_migrated_ok | bool
      delegate_to: localhost
      ansible.builtin.set_fact:
        cleanup_report: >-
          {{
            cleanup_report ~
            (
              ('; pending reboot found, cancelled (pids=' ~ (reboot_kill.stdout | trim) ~ ')')
              if ((reboot_kill.stdout | default('') | trim) not in ['','NONE'])
              else
              '; no pending reboot found'
            )
          }}
      changed_when: false

    - name: CASE A | Final cumulative cleanup report
      when: dhcp_migrated_ok | bool
      delegate_to: localhost
      ansible.builtin.debug:
        msg:
          - "{{ cleanup_report }}"
      changed_when: false