---
- name: Tailscale Health Check (Homelab)
  hosts: active            # or "all" if you want to check everything
  gather_facts: yes
  become: false

  vars:
    tailscale_bin: "/usr/bin/tailscale"
    tailscale_service: "tailscaled"

  tasks:

    - name: Verify Tailscale binary exists
      stat:
        path: "{{ tailscale_bin }}"
      register: ts_bin
      ignore_errors: true

    - name: Skip host if Tailscale not installed
      meta: end_host
      when: not ts_bin.stat.exists

    - name: Get Tailscale CLI version
      command: "{{ tailscale_bin }} version"
      register: ts_version
      changed_when: false
      failed_when: false

    - name: Get Tailscale status (JSON)
      command: "{{ tailscale_bin }} status --json"
      register: ts_status
      changed_when: false
      failed_when: false

    - name: Parse Tailscale JSON
      set_fact:
        ts_parsed: "{{ ts_status.stdout | from_json }}"
      when: ts_status.rc == 0 and (ts_status.stdout | length) > 0 and ts_status.stdout is search('{')

    - name: Extract important fields
      set_fact:
        ts_backend_state: "{{ ts_parsed.BackendState | default('unknown') }}"
        ts_ips: "{{ ts_parsed.Self.TailscaleIPs | default([]) }}"
        ts_hostname: "{{ ts_parsed.Self.HostName | default(inventory_hostname) }}"
      when: ts_parsed is defined

    - name: Report healthy nodes
      debug:
        msg: >-
          HEALTHY: {{ ts_hostname }}
          version={{ ts_version.stdout | default('n/a') }},
          backend={{ ts_backend_state }},
          ips={{ ts_ips }}
      when:
        - ts_parsed is defined
        - ts_backend_state == "Running"
        - ts_ips | length > 0

    - name: Report unhealthy or unreachable nodes
      debug:
        msg: >-
          UNHEALTHY: {{ inventory_hostname }}
          rc={{ ts_status.rc }},
          backend={{ ts_backend_state | default('n/a') }},
          ips={{ ts_ips | default([]) }},
          version={{ ts_version.stdout | default('n/a') }}
      when: ts_parsed is not defined or ts_backend_state != "Running"

    - name: Always print concise summary
      debug:
        msg: >-
          Host={{ inventory_hostname }},
          Version={{ ts_version.stdout | default('n/a') }},
          Backend={{ ts_backend_state | default('unknown') }},
          IPs={{ ts_ips | default([]) }}