- name: Install Node Exporter from binary
  hosts: all
  become: true

  vars:
    node_exporter_version: "1.9.1"
    node_exporter_user: "node_exporter"
    node_exporter_listen: "0.0.0.0:9100"
    node_exporter_bin_dir: "/usr/local/bin"
    node_exporter_service_path: "/etc/systemd/system/node_exporter.service"
    node_exporter_arch_map:
      x86_64: "amd64"
      aarch64: "arm64"
      armv7l: "armv7"
    node_exporter_arch: "{{ node_exporter_arch_map[ansible_architecture] | default('amd64') }}"

  tasks:
    - name: Debug detected architecture
      debug:
        msg: "Detected architecture: {{ ansible_architecture }} -> using {{ node_exporter_arch }} build"

    - name: Ensure node_exporter user exists
      user:
        name: "{{ node_exporter_user }}"
        shell: /usr/sbin/nologin
        system: true
        create_home: false

    - name: Download Node Exporter archive
      get_url:
        url: "https://github.com/prometheus/node_exporter/releases/download/v{{ node_exporter_version }}/node_exporter-{{ node_exporter_version }}.linux-{{ node_exporter_arch }}.tar.gz"
        dest: "/tmp/node_exporter.tar.gz"
        mode: "0644"

    - name: Extract Node Exporter binary
      unarchive:
        src: "/tmp/node_exporter.tar.gz"
        dest: "/tmp/"
        remote_src: true

    - name: Move Node Exporter binary into place
      command: mv /tmp/node_exporter-{{ node_exporter_version }}.linux-{{ node_exporter_arch }}/node_exporter {{ node_exporter_bin_dir }}/node_exporter

    - name: Set binary permissions
      file:
        path: "{{ node_exporter_bin_dir }}/node_exporter"
        mode: "0755"
        owner: root
        group: root

    - name: Create systemd service
      copy:
        dest: "{{ node_exporter_service_path }}"
        content: |
          [Unit]
          Description=Prometheus Node Exporter
          After=network.target

          [Service]
          User={{ node_exporter_user }}
          ExecStart={{ node_exporter_bin_dir }}/node_exporter --web.listen-address={{ node_exporter_listen }}
          Restart=always

          [Install]
          WantedBy=multi-user.target
      notify: Restart node_exporter

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

  handlers:
    - name: Restart node_exporter
      systemd:
        name: node_exporter
        state: restarted