---
- name: Roll back native PostgreSQL delivery instances
  hosts: "{{ target_hosts }}"
  become: true
  gather_facts: false
  any_errors_fatal: true
  vars:
    postgresql_instance_plan: "{{ postgresql_instances[inventory_hostname] | default({}) }}"
    postgresql_instance_id: "{{ postgresql_instance_plan.instance_id | default('') }}"
    postgresql_data_root: /data/postgresql
    postgresql_instance_root: "{{ postgresql_data_root }}/{{ postgresql_instance_id }}"
    postgresql_data_dir: "{{ postgresql_instance_plan.data_dir | default('') }}"
    postgresql_config_dir: "{{ postgresql_instance_plan.config_dir | default('') }}"
    postgresql_log_dir: "{{ postgresql_instance_plan.log_dir | default('') }}"
    postgresql_systemd_unit: "{{ postgresql_instance_plan.systemd_unit | default('') }}"
    postgresql_dropin_dir: "/etc/systemd/system/{{ postgresql_systemd_unit }}.d"
    postgresql_run_dir: "/run/postgresql-xinfra/{{ postgresql_instance_id }}"

  pre_tasks:
    - name: Validate PostgreSQL rollback target
      ansible.builtin.assert:
        that:
          - postgresql_instance_plan is mapping
          - postgresql_instance_id is match('^[a-z0-9][a-z0-9-]{0,62}$')
          - postgresql_instance_root == '/data/postgresql/' + postgresql_instance_id
          - postgresql_data_dir == postgresql_instance_root + '/data'
          - postgresql_config_dir == postgresql_instance_root + '/conf'
          - postgresql_log_dir == postgresql_instance_root + '/log'
          - postgresql_systemd_unit == 'postgresql-xinfra@' + postgresql_instance_id + '.service'
          - postgresql_instance_root != '/data/postgresql'
          - "'..' not in postgresql_instance_root"
        fail_msg: "Rollback target is outside the native PostgreSQL delivery layout"
        quiet: true

  tasks:
    - name: Stop the PostgreSQL delivery instance when present
      ansible.builtin.systemd_service:
        name: "{{ postgresql_systemd_unit }}"
        state: stopped
        enabled: false
      failed_when: false

    - name: Reset the PostgreSQL instance failure state
      ansible.builtin.command:
        argv:
          - systemctl
          - reset-failed
          - "{{ postgresql_systemd_unit }}"
      changed_when: false
      failed_when: false

    - name: Remove the PostgreSQL instance systemd drop-in
      ansible.builtin.file:
        path: "{{ postgresql_dropin_dir }}"
        state: absent

    - name: Remove the PostgreSQL instance data, configuration, and logs
      ansible.builtin.file:
        path: "{{ postgresql_instance_root }}"
        state: absent

    - name: Remove the PostgreSQL instance runtime directory
      ansible.builtin.file:
        path: "{{ postgresql_run_dir }}"
        state: absent

    - name: Reload systemd after removing the instance drop-in
      ansible.builtin.systemd_service:
        daemon_reload: true

    - name: Confirm PostgreSQL instance artifacts are gone
      ansible.builtin.stat:
        path: "{{ item }}"
      loop:
        - "{{ postgresql_dropin_dir }}"
        - "{{ postgresql_instance_root }}"
        - "{{ postgresql_run_dir }}"
      register: postgresql_rollback_artifacts

    - name: Assert all PostgreSQL instance artifacts are gone
      ansible.builtin.assert:
        that:
          - not item.stat.exists
        fail_msg: "PostgreSQL rollback left an instance artifact on the target host"
        quiet: true
      loop: "{{ postgresql_rollback_artifacts.results }}"