---
- name: Check if node_exporter is installed
  stat:
    path: /usr/local/bin/node_exporter
  register: ne_bin

- name: Set architecture
  set_fact:
    ne_arch: "{{ 'arm64' if ansible_architecture == 'aarch64' else 'amd64' }}"

- name: Get latest node_exporter version
  uri:
    url: https://api.github.com/repos/prometheus/node_exporter/releases/latest
    return_content: yes
  register: ne_release
  when: not ne_bin.stat.exists

- name: Set node_exporter version
  set_fact:
    ne_version: "{{ ne_release.json.tag_name | regex_replace('^v', '') }}"
  when: not ne_bin.stat.exists

- name: Download node_exporter
  get_url:
    url: "https://github.com/prometheus/node_exporter/releases/download/v{{ ne_version }}/node_exporter-{{ ne_version }}.linux-{{ ne_arch }}.tar.gz"
    dest: /tmp/node_exporter.tar.gz
  when: not ne_bin.stat.exists

- name: Extract node_exporter
  unarchive:
    src: /tmp/node_exporter.tar.gz
    dest: /tmp/
    remote_src: yes
  when: not ne_bin.stat.exists

- name: Install node_exporter binary
  copy:
    src: "/tmp/node_exporter-{{ ne_version }}.linux-{{ ne_arch }}/node_exporter"
    dest: /usr/local/bin/node_exporter
    owner: root
    group: root
    mode: '0755'
    remote_src: yes
  when: not ne_bin.stat.exists
  notify: restart node_exporter

- name: Create node_exporter user
  user:
    name: node_exporter
    system: yes
    shell: /usr/sbin/nologin
    create_home: no

- name: Deploy node_exporter systemd service
  copy:
    content: |
      [Unit]
      Description=Prometheus Node Exporter
      After=network-online.target
      Wants=network-online.target

      [Service]
      User=node_exporter
      Group=node_exporter
      Type=simple
      ExecStart=/usr/local/bin/node_exporter --collector.textfile.directory=/var/lib/node_exporter/textfile
      Restart=on-failure
      RestartSec=5

      [Install]
      WantedBy=multi-user.target
    dest: /etc/systemd/system/node_exporter.service
    owner: root
    group: root
    mode: '0644'
  notify: restart node_exporter

- name: Create textfile collector directory
  file:
    path: /var/lib/node_exporter/textfile
    state: directory
    owner: node_exporter
    group: node_exporter
    mode: '0755'

- name: Deploy CPU temperature collector script
  copy:
    content: |
      #!/bin/bash
      TEMP=$(vcgencmd measure_temp 2>/dev/null | grep -oP '[0-9.]+')
      if [ -n "$TEMP" ]; then
        echo "# HELP node_cpu_temperature_celsius CPU temperature from vcgencmd"
        echo "# TYPE node_cpu_temperature_celsius gauge"
        echo "node_cpu_temperature_celsius $TEMP"
      fi > /var/lib/node_exporter/textfile/cpu_temp.prom
    dest: /usr/local/bin/collect-cpu-temp.sh
    mode: '0755'

- name: Schedule CPU temperature collection (every minute)
  cron:
    name: "node_exporter cpu temp"
    user: node_exporter
    job: "/usr/local/bin/collect-cpu-temp.sh"

- name: Run initial temperature collection
  command: /usr/local/bin/collect-cpu-temp.sh
  changed_when: false

- name: Enable and start node_exporter
  systemd:
    name: node_exporter
    enabled: yes
    state: started
    daemon_reload: yes

- name: Clean up download
  file:
    path: /tmp/node_exporter.tar.gz
    state: absent
  when: not ne_bin.stat.exists