---
- name: Install and Configure Elasticsearch 9
  hosts: elasticsearch # Target your hosts here (e.g., from your inventory file)
  become: true
  vars:
    # UPDATED: Set to a specific version 9 release for predictable deployments.
    es_version: "9.0.0" # Change to the specific ES9 version you want to deploy
    es_cluster_name: "cluster-v9"
    es_node_name: "{{ ansible_hostname }}"
    es_network_host: "{{ ansible_default_ipv4.address }}" # Binds to the primary private IP
    es_heap_size: "{{ (ansible_memtotal_mb * 0.5) | int }}m" # Use 50% of total RAM. For 32GB RAM, this sets ~16GB.

    # --- For multi-node clusters, override these in your inventory ---
    es_seed_hosts: ["{{ es_network_host }}"]
    es_initial_master_nodes: ["{{ es_node_name }}"]

  tasks:
    - name: "BLOCK: System Preparation"
      block:
        - name: Update APT package cache
          ansible.builtin.apt:
            update_cache: true
            cache_valid_time: 3600

        - name: Install prerequisite packages
          ansible.builtin.apt:
            name:
              - apt-transport-https
              - ca-certificates
              - gnupg
              # UPDATED: Elasticsearch 9 requires Java 21+
              - openjdk-21-jdk
            state: present

    - name: "BLOCK: System Tuning for Elasticsearch"
      block:
        - name: Set vm.max_map_count for Elasticsearch
          ansible.posix.sysctl:
            name: vm.max_map_count
            value: "262144"
            state: present
            reload: true

        - name: Set Elasticsearch user memory limit
          community.general.pam_limits:
            domain: "elasticsearch"
            limit_type: "-"
            limit_item: "memlock"
            value: "unlimited"
            comment: "Allow memory locking"

        - name: Set Elasticsearch user file descriptor limit
          community.general.pam_limits:
            domain: "elasticsearch"
            limit_type: "-"
            limit_item: "nofile"
            value: "65536"
            comment: "Set max open files"

    - name: "BLOCK: Install Elasticsearch"
      block:
        - name: Download Elasticsearch GPG key
          ansible.builtin.get_url:
            url: "https://artifacts.elastic.co/GPG-KEY-elasticsearch"
            dest: "/tmp/GPG-KEY-elasticsearch"
            mode: '0644'

        - name: De-armor the GPG key
          ansible.builtin.command:
            cmd: "gpg --dearmor -o /etc/apt/trusted.gpg.d/elasticsearch.gpg /tmp/GPG-KEY-elasticsearch"
            creates: "/etc/apt/trusted.gpg.d/elasticsearch.gpg"

        - name: Add Elasticsearch 9.x APT repository
          # UPDATED: Repository path changed from 8.x to 9.x
          ansible.builtin.apt_repository:
            repo: "deb https://artifacts.elastic.co/packages/9.x/apt stable main"
            state: present
            filename: elastic-9.x

        - name: Install Elasticsearch package
          ansible.builtin.apt:
            name: "elasticsearch={{ es_version }}"
            state: present
            update_cache: true

    - name: "BLOCK: Configure Elasticsearch"
      block:
        - name: Configure elasticsearch.yml
          ansible.builtin.template:
            src: templates/elasticsearch.yml.j2
            dest: /etc/elasticsearch/elasticsearch.yml
            owner: root
            group: elasticsearch
            mode: '0660'
          notify: Restart Elasticsearch

        - name: Configure JVM heap size
          ansible.builtin.template:
            src: templates/jvm.options.j2
            dest: /etc/elasticsearch/jvm.options.d/heap_size.options
            owner: root
            group: root
            mode: '0644'
          notify: Restart Elasticsearch

    - name: Flush handlers to apply config changes before starting the service
      ansible.builtin.meta: flush_handlers

    - name: Enable and ensure Elasticsearch service is started
      ansible.builtin.systemd:
        name: elasticsearch
        state: started
        enabled: true
        daemon_reload: true

    - name: Wait for Elasticsearch to start up on port 9200
      ansible.builtin.wait_for:
        host: "{{ es_network_host }}"
        port: 9200
        delay: 10
        timeout: 120
      delegate_to: localhost

  handlers:
    - name: Restart Elasticsearch
      ansible.builtin.systemd:
        name: elasticsearch
        state: restarted