---
- name: 检查现有 PGDATA
  ansible.builtin.stat:
    path: "{{ pg_data_root }}/{{ pg_instance }}/data/PG_VERSION"
  register: pg_existing_version
- name: 检查本项目所有权标记
  ansible.builtin.stat:
    path: "{{ pg_data_root }}/{{ pg_instance }}/.homelab-owned"
  register: pg_owned_marker
- name: 拒绝接管未知现有实例
  ansible.builtin.assert:
    that: not pg_existing_version.stat.exists or pg_owned_marker.stat.exists
    fail_msg: 发现未登记 PGDATA，停止；导入和恢复必须使用独立流程。
- name: 核对已登记实例
  when: pg_owned_marker.stat.exists
  block:
    - name: 读取实例标记
      ansible.builtin.slurp:
        src: "{{ pg_data_root }}/{{ pg_instance }}/.homelab-owned"
      register: pg_marker_content
    - name: 验证实例身份
      ansible.builtin.assert:
        that: (pg_marker_content.content | b64decode | trim) == ('shared-postgresql/' ~ pg_instance)
- name: 核对已有实例主版本，禁止隐式升级
  when: pg_existing_version.stat.exists
  block:
    - name: 读取 PG_VERSION
      ansible.builtin.slurp:
        src: "{{ pg_data_root }}/{{ pg_instance }}/data/PG_VERSION"
      register: pg_existing_version_content
    - name: 主版本必须匹配
      ansible.builtin.assert:
        that: (pg_existing_version_content.content | b64decode | trim) == (pg_major | string)