---
# Konfiguracja replikacji PostgreSQL
# Ta rola uruchamia się na replica (pg2)
# Tworzy użytkownika replicator i base backup z primary

# --- Auto-detect PostgreSQL version na primary ---
- name: Detect PostgreSQL version on primary
  shell: "ls -d /etc/postgresql/*/ | head -1 | xargs basename"
  register: pg_version_detect
  changed_when: false
  delegate_to: pg1
  run_once: true

- name: Set PostgreSQL variables from detection
  set_fact:
    pg_version: "{{ pg_version_detect.stdout | trim }}"
    pg_cluster: "main"
    pg_data: "/var/lib/postgresql/{{ pg_version_detect.stdout | trim }}/main"
    pg_bin_path: "/usr/lib/postgresql/{{ pg_version_detect.stdout | trim }}/bin"

- name: Wait for PostgreSQL on primary to be ready
  wait_for:
    host: pg1
    port: 5432
    timeout: 300
  delegate_to: pg1

# --- Utworzenie użytkownika replicator na primary ---
- name: Create replicator user on primary
  postgresql_user:
    name: replicator
    password: "{{ replicator_password }}"
    role_attr_flags: REPLICATION,LOGIN
    login_unix_socket_directory: /var/run/postgresql
    db: postgres
  become: true
  become_user: postgres
  delegate_to: pg1

# --- Przygotowanie replica ---
- name: Stop PostgreSQL on replica
  systemd:
    name: postgresql
    state: stopped

- name: Remove existing cluster data on replica
  file:
    path: "{{ pg_data }}"
    state: absent

# --- Base backup z primary ---
- name: Create replication slot on primary
  postgresql_query:
    db: postgres
    query: "SELECT pg_create_physical_replication_slot('pg2_slot')"
    login_unix_socket_directory: /var/run/postgresql
  become: true
  become_user: postgres
  delegate_to: pg1
  ignore_errors: true

- name: Perform base backup from primary to replica
  shell: |
    pg_basebackup \
      -h pg1 \
      -D {{ pg_data }} \
      -U replicator \
      -Fp \
      -Xs \
      -P \
      -R \
      -S pg2_slot
  become: true
  become_user: postgres
  register: basebackup_result

- name: Fix permissions on data directory
  file:
    path: "{{ pg_data }}"
    owner: postgres
    group: postgres
    mode: "0700"
    recurse: yes
  become: true

- name: Configure replication settings
  lineinfile:
    path: "{{ pg_data }}/standby.signal"
    line: ""
    create: yes
    owner: postgres
    group: postgres
    mode: "0644"

# --- Uruchomienie replica ---
- name: Start PostgreSQL on replica
  systemd:
    name: postgresql
    state: started
    enabled: yes

- name: Wait for PostgreSQL replica to be ready
  wait_for:
    path: "/var/run/postgresql/.s.PGSQL.5432"
    timeout: 60
    state: present

- name: Verify replication on primary
  postgresql_query:
    db: postgres
    query: "SELECT application_name, client_addr, state FROM pg_stat_replication"
    login_unix_socket_directory: /var/run/postgresql
  become: true
  become_user: postgres
  delegate_to: pg1
  register: replication_status

- name: Display replication status
  debug:
    msg: "{{ replication_status.query_result }}"