---
- name: Backup SlurmDBD MariaDB database
  hosts: slurm_controller
  become: true
  gather_facts: true

  vars:
    slurmdbd_backup_dir: /var/backups/slurmdbd
    local_fetch_dir: "{{ playbook_dir }}/../../artifacts/backups/slurmdbd"

  tasks:
    - name: Create remote backup directory
      ansible.builtin.file:
        path: "{{ slurmdbd_backup_dir }}"
        state: directory
        owner: root
        group: root
        mode: "0700"

    - name: Create local fetch directory on Ansible controller
      ansible.builtin.file:
        path: "{{ local_fetch_dir }}"
        state: directory
        owner: root
        group: root
        mode: "0700"
      delegate_to: localhost
      become: false

    - name: Validate MariaDB is running
      ansible.builtin.command:
        cmd: systemctl is-active mariadb
      changed_when: false

    - name: Validate SlurmDBD is running
      ansible.builtin.command:
        cmd: systemctl is-active slurmdbd
      changed_when: false

    - name: Validate Slurm accounting database exists
      ansible.builtin.shell: |
        set -euo pipefail
        mysql -N -B -e "SHOW DATABASES LIKE '{{ slurmdbd_storage_loc }}';" | grep -qx "{{ slurmdbd_storage_loc }}"
      args:
        executable: /bin/bash
      changed_when: false

    - name: Dump Slurm accounting database
      ansible.builtin.shell: |
        set -euo pipefail

        ts="$(date +%F-%H%M%S)"
        out="{{ slurmdbd_backup_dir }}/{{ slurmdbd_storage_loc }}-${ts}.sql.gz"

        mysqldump \
          --single-transaction \
          --routines \
          --events \
          --triggers \
          {{ slurmdbd_storage_loc }} | gzip -9 > "$out"

        chmod 0600 "$out"
        echo "$out"
      args:
        executable: /bin/bash
      register: db_dump
      changed_when: true

    - name: Validate backup file is non-empty
      ansible.builtin.stat:
        path: "{{ db_dump.stdout }}"
      register: backup_file

    - name: Fail if backup file is empty
      ansible.builtin.fail:
        msg: "Backup file is empty: {{ db_dump.stdout }}"
      when: backup_file.stat.size | int < 1024

    - name: Fetch DB backup to Ansible controller
      ansible.builtin.fetch:
        src: "{{ db_dump.stdout }}"
        dest: "{{ local_fetch_dir }}/"
        flat: true

    - name: Show DB backup result
      ansible.builtin.debug:
        msg:
          - "Remote backup: {{ db_dump.stdout }}"
          - "Backup size bytes: {{ backup_file.stat.size }}"
          - "Fetched to: {{ local_fetch_dir }}/"