---
# ------------------------------------------------------------------------------
# FILE: roles/llm-inference-multimodel/tasks/discover.yml
# DESCRIPTION: Phase 0 — READ-ONLY fact gathering on how the existing Gemma
#              llama-server is actually managed on astro-orbiter TODAY.
#
#              Per plan §0/§4: "Service management: unverified — plan requires
#              confirming systemd unit exists before touching anything.
#              Do not assume." This file performs that confirmation. It makes
#              NO changes to the host — no `state: present/started/stopped`,
#              no file writes, no service actions. Every task here is either
#              a `_facts` module, a `command`/`shell` in check-safe read mode,
#              or a `stat`.
#
#              Outcomes recorded as facts for later phases/for a human to read
#              in the play recap — this file does not branch role behavior
#              on the result (that would be over-engineering a role meant to
#              run once); it surfaces what's true so a human confirms before
#              Phase 2 proceeds.
# ------------------------------------------------------------------------------

- name: Gather service facts (systemd unit inventory)
  ansible.builtin.service_facts:

- name: Determine whether a systemd unit matching the existing Gemma service exists
  ansible.builtin.set_fact:
    llm_existing_gemma_unit_found: "{{ (llm_existing_gemma_service_name_guess + '.service') in ansible_facts.services }}"

- name: Report existing Gemma systemd unit state (if found)
  ansible.builtin.debug:
    msg: >-
      Existing unit '{{ llm_existing_gemma_service_name_guess }}.service' found:
      state={{ ansible_facts.services[llm_existing_gemma_service_name_guess + '.service'].state | default('unknown') }},
      status={{ ansible_facts.services[llm_existing_gemma_service_name_guess + '.service'].status | default('unknown') }}
  when: llm_existing_gemma_unit_found

- name: WARNING — no systemd unit found matching the existing Gemma service
  ansible.builtin.debug:
    msg: >-
      No systemd unit named '{{ llm_existing_gemma_service_name_guess }}.service'
      was found via service_facts. This means the current single-model
      llama-server is likely run some other way (manual nohup, screen/tmux,
      or a differently-named unit). DO NOT PROCEED to Phase 2 assuming a
      clean rollback target exists. Before continuing: (1) check for any
      running llama-server process via `ansible -m command -a "pgrep -fa
      llama-server"`, (2) if found running ad hoc, codify it as a proper
      systemd unit FIRST (reusing roles/llm-inference's existing
      llama-server.service.j2 pattern) so plan §6's rollback story
      ("systemctl start llama-server-gemma to fully revert") is real and
      not aspirational. This is a human decision point, not something this
      role auto-remediates.
  when: not llm_existing_gemma_unit_found

- name: Check for any running llama-server process (read-only, no state change)
  ansible.builtin.command:
    cmd: pgrep -fa llama-server
  register: llm_existing_process_check
  changed_when: false
  failed_when: false   # pgrep exits 1 with no matches — not a failure condition here

- name: Report any llama-server process found running outside systemd
  ansible.builtin.debug:
    msg: "Running llama-server process(es): {{ llm_existing_process_check.stdout_lines }}"
  when: llm_existing_process_check.rc == 0

- name: Check current GPU VRAM utilization (baseline, before any changes)
  ansible.builtin.command:
    cmd: nvidia-smi --query-gpu=memory.used,memory.total --format=csv,noheader
  register: llm_baseline_vram
  changed_when: false
  failed_when: false

- name: Report baseline VRAM usage
  ansible.builtin.debug:
    msg: "Baseline GPU VRAM (before this role's changes): {{ llm_baseline_vram.stdout | default('nvidia-smi unavailable') }}"

- name: Check whether ports 8000/8001 are already bound (avoid port collision surprises)
  ansible.builtin.command:
    cmd: "ss -ltnp"
  register: llm_existing_listeners
  changed_when: false
  failed_when: false

- name: Report current listeners on 8000/8001
  ansible.builtin.debug:
    msg: "{{ llm_existing_listeners.stdout_lines | select('search', ':(8000|8001)\\s') | list }}"
  when: llm_existing_listeners.rc == 0