---
# cezen-backend role: installs the Nexus One AI FastAPI management API

- name: Install system Python deps
  apt:
    name:
      - python3-pip
      - python3-venv
      - python3.11
      - python3.11-venv
      - libmupdf-dev      # required by pymupdf (Document Intelligence)
      - mupdf-tools
      - ffmpeg            # required by faster-whisper audio transcription
    state: present
    update_cache: yes

- name: Create backend directory
  file:
    path: /opt/cezen/backend
    state: directory
    owner: "{{ cezen_user }}"
    group: "{{ cezen_user }}"
    mode: "0755"

- name: Create data directory (JWT secret + SQLite DB)
  file:
    path: /opt/cezen/data
    state: directory
    owner: "{{ cezen_user }}"
    group: "{{ cezen_user }}"
    mode: "0750"

- name: Check for captured license file
  stat:
    path: /opt/cezen/license.json
  register: cezen_license_file

- name: Allow backend service to read captured license
  file:
    path: /opt/cezen/license.json
    owner: root
    group: "{{ cezen_user }}"
    mode: "0640"
  when: cezen_license_file.stat.exists

- name: Copy FastAPI application
  copy:
    src: main.py
    dest: /opt/cezen/backend/main.py
    owner: "{{ cezen_user }}"
    group: "{{ cezen_user }}"
    mode: "0644"
  notify: Restart cezen-api

- name: Copy QLoRA training runner
  copy:
    src: train_qlora.py
    dest: /opt/cezen/backend/train_qlora.py
    owner: "{{ cezen_user }}"
    group: "{{ cezen_user }}"
    mode: "0755"

- name: Copy RAG ingest worker
  copy:
    src: rag_ingest.py
    dest: /opt/cezen/backend/rag_ingest.py
    owner: "{{ cezen_user }}"
    group: "{{ cezen_user }}"
    mode: "0755"
  notify: Restart cezen-api

- name: Copy requirements.txt
  copy:
    src: requirements.txt
    dest: /opt/cezen/backend/requirements.txt
    owner: "{{ cezen_user }}"
    group: "{{ cezen_user }}"
    mode: "0644"

- name: Create Python virtual environment (Python 3.11)
  become_user: "{{ cezen_user }}"
  command: python3.11 -m venv /opt/cezen/backend/venv
  args:
    creates: /opt/cezen/backend/venv/bin/activate

- name: Install Python dependencies
  become_user: "{{ cezen_user }}"
  pip:
    requirements: /opt/cezen/backend/requirements.txt
    virtualenv: /opt/cezen/backend/venv
  notify: Restart cezen-api

- name: Install Pro/Max fine-tuning dependencies
  become_user: "{{ cezen_user }}"
  pip:
    name:
      - torch
      - transformers
      - datasets
      - peft
      - bitsandbytes
      - accelerate
      - trl
      - sentencepiece
    virtualenv: /opt/cezen/backend/venv
  retries: 3
  delay: 15
  when: (tier | default('basic')) in ['pro', 'max']

- name: Install Max multi-GPU training dependencies
  become_user: "{{ cezen_user }}"
  pip:
    name:
      - deepspeed
    virtualenv: /opt/cezen/backend/venv
  retries: 3
  delay: 15
  when: (tier | default('basic')) == 'max'

- name: Install systemd service unit
  copy:
    src: cezen-api.service
    dest: /etc/systemd/system/cezen-api.service
    owner: root
    group: root
    mode: "0644"
  notify:
    - Reload systemd
    - Restart cezen-api

- name: Enable and start cezen-api service
  systemd:
    name: cezen-api
    enabled: yes
    state: started
    daemon_reload: yes