---
- name: Ensure hardware detection utilities are present
  ansible.builtin.apt:
    name:
      - pciutils
      - ubuntu-drivers-common
    state: present
    update_cache: true
  when: ansible_distribution == "Ubuntu"

- name: Ensure hardware detection utilities are present (non-Ubuntu)
  ansible.builtin.apt:
    name:
      - pciutils
    state: present
    update_cache: true
  when: ansible_distribution != "Ubuntu"

- name: Detect PCI devices
  ansible.builtin.command: lspci
  register: nvidia_runtime_lspci
  changed_when: false

- name: Set hardware detection fact
  ansible.builtin.set_fact:
    nvidia_runtime_has_gpu: "{{ 'NVIDIA' in nvidia_runtime_lspci.stdout }}"

- name: Stop when GPU is required but missing
  ansible.builtin.fail:
    msg: "No NVIDIA GPU detected on this host."
  when:
    - nvidia_runtime_require_gpu | bool
    - not nvidia_runtime_has_gpu | bool

- name: Detect recommended Ubuntu NVIDIA driver
  ansible.builtin.command: ubuntu-drivers devices
  register: nvidia_runtime_ubuntu_drivers
  changed_when: false
  failed_when: false
  when:
    - ansible_distribution == "Ubuntu"
    - nvidia_runtime_driver_package | length == 0

- name: Derive auto-selected driver package
  ansible.builtin.set_fact:
    nvidia_runtime_selected_driver: >-
      {{
        nvidia_runtime_driver_package
        if (nvidia_runtime_driver_package | length > 0)
        else (
          (nvidia_runtime_ubuntu_drivers.stdout | default(''))
          | regex_search('nvidia-driver-[0-9]+')
          | default('')
        )
      }}

- name: Validate selected driver package
  ansible.builtin.fail:
    msg: >-
      Could not determine an NVIDIA driver package automatically.
      Set nvidia_runtime_driver_package explicitly.
  when:
    - nvidia_runtime_install_driver | bool
    - nvidia_runtime_selected_driver | length == 0