---
- name: Configure Borgmatic backup with deterministic offset
  hosts: all
  become: true

  vars:
    borgmatic_bin: /usr/local/bin/borgmatic
    backup_hour: 2                # Base hour to run backups
    backup_window: 1800           # 30 min window (in seconds)
    borgmatic_config_dir: /etc/borgmatic

  tasks:
    - name: Ensure Borg and dependencies are present
      package:
        name:
          - borgbackup
          - python3-pip
        state: present

    - name: Ensure borgmatic is installed via pip
      pip:
        name: borgmatic
        executable: pip3

    - name: Create borgmatic config directory
      file:
        path: "{{ borgmatic_config_dir }}"
        state: directory
        owner: root
        group: root
        mode: '0755'

    - name: Generate deterministic backup offset
      set_fact:
        backup_offset: >-
          {{ (inventory_hostname | hash('md5') | int(base=16)) % backup_window }}

    - name: Split offset into minutes and seconds
      set_fact:
        backup_offset_minutes: "{{ backup_offset // 60 }}"
        backup_offset_seconds: "{{ backup_offset % 60 }}"

    - name: Deploy borgmatic config
      template:
        src: templates/borg/borgmatic-config.yaml.j2
        dest: "{{ borgmatic_config_dir }}/config.yaml"
        owner: root
        group: root
        mode: '0600'

    - name: Create cron job for borgmatic with offset
      cron:
        name: "Nightly borgmatic backup"
        user: root
        hour: "{{ backup_hour }}"
        minute: "{{ backup_offset_minutes }}"
        job: "sleep {{ backup_offset_seconds }} && {{ borgmatic_bin }} --verbosity 1"