---
# =============================================================================
# Configure Swap on Systems Without It
# =============================================================================
# This playbook creates and enables a swap file on systems that don't have
# swap configured, bringing them into CLAUDE.md compliance.
#
# Usage:
#   ansible-playbook playbooks/configure_swap.yml
#   ansible-playbook playbooks/configure_swap.yml --limit pihole
#
# Tags:
#   - swap: All swap-related tasks
#   - validate: Validation tasks only
# =============================================================================

- name: Configure Swap on Systems Without Adequate Swap
  hosts: all
  become: yes
  gather_facts: yes

  vars:
    swap_file_path: /swapfile
    swap_size_mb: 2048  # 2GB - CLAUDE.md compliant
    swap_minimum_mb: 512  # Only configure if less than this

  tasks:
    - name: Check current swap configuration
      command: swapon --show --bytes
      register: current_swap
      changed_when: false
      failed_when: false
      tags: [swap, validate]

    - name: Parse current swap size
      set_fact:
        current_swap_mb: >-
          {% if current_swap.stdout_lines | length > 1 %}
          {{ (current_swap.stdout_lines[1].split()[2] | int / 1024 / 1024) | int }}
          {% else %}
          0
          {% endif %}
      tags: [swap]

    - name: Display current swap status
      debug:
        msg:
          - "Current swap size: {{ current_swap_mb }} MB"
          - "Target swap size: {{ swap_size_mb }} MB"
          - "Will configure swap: {{ current_swap_mb | int < swap_minimum_mb }}"
      tags: [swap]

    - name: Configure swap if needed
      block:
        - name: Check if swap file already exists
          stat:
            path: "{{ swap_file_path }}"
          register: swap_file_stat

        - name: Check available disk space
          shell: df -BM {{ swap_file_path | dirname }} | tail -1 | awk '{print $4}' | sed 's/M//'
          register: available_space
          changed_when: false

        - name: Verify sufficient disk space
          assert:
            that:
              - available_space.stdout | int > swap_size_mb | int
            fail_msg: "Insufficient disk space. Available: {{ available_space.stdout }}MB, Required: {{ swap_size_mb }}MB"
            success_msg: "Sufficient disk space available: {{ available_space.stdout }}MB"

        - name: Create swap file
          command: dd if=/dev/zero of={{ swap_file_path }} bs=1M count={{ swap_size_mb }}
          args:
            creates: "{{ swap_file_path }}"
          register: swap_file_created
          tags: [swap]

        - name: Set correct permissions on swap file
          file:
            path: "{{ swap_file_path }}"
            mode: '0600'
            owner: root
            group: root
          tags: [swap]

        - name: Format swap file
          command: mkswap {{ swap_file_path }}
          when: swap_file_created is changed
          register: swap_formatted
          tags: [swap]

        - name: Enable swap file
          command: swapon {{ swap_file_path }}
          when:
            - swap_file_path not in current_swap.stdout
            - swap_formatted is succeeded or swap_file_stat.stat.exists
          register: swap_enabled
          tags: [swap]

        - name: Check if swap is in fstab
          lineinfile:
            path: /etc/fstab
            regexp: "^{{ swap_file_path }}"
            state: absent
          check_mode: yes
          register: fstab_check
          changed_when: false
          tags: [swap]

        - name: Add swap to fstab for persistence
          lineinfile:
            path: /etc/fstab
            line: "{{ swap_file_path }} none swap sw 0 0"
            state: present
            backup: yes
          when: fstab_check is not changed
          tags: [swap]

        - name: Verify swap is active
          command: swapon --show
          register: final_swap
          changed_when: false
          tags: [swap, validate]

        - name: Get swap usage statistics
          command: free -h
          register: swap_stats
          changed_when: false
          tags: [swap, validate]

        - name: Display swap configuration success
          debug:
            msg:
              - "=== Swap Configuration Complete ==="
              - "Swap file: {{ swap_file_path }}"
              - "Size: {{ swap_size_mb }} MB"
              - "Active swaps:"
              - "{{ final_swap.stdout_lines }}"
              - ""
              - "Memory status:"
              - "{{ swap_stats.stdout_lines }}"
          tags: [swap]

      rescue:
        - name: Swap configuration failed - cleanup
          debug:
            msg:
              - "=== Swap Configuration Failed ==="
              - "Error occurred during swap configuration"
              - "Attempting cleanup..."

        - name: Disable swap file if partially configured
          command: swapoff {{ swap_file_path }}
          failed_when: false
          tags: [swap]

        - name: Remove incomplete swap file
          file:
            path: "{{ swap_file_path }}"
            state: absent
          when: swap_file_created is changed
          failed_when: false
          tags: [swap]

        - name: Fail with error message
          fail:
            msg: |
              Swap configuration failed. Please check:
              1. Sufficient disk space ({{ swap_size_mb }}MB required)
              2. Permissions to create {{ swap_file_path }}
              3. System logs: journalctl -xe

      when: current_swap_mb | int < swap_minimum_mb

    - name: Swap already configured adequately
      debug:
        msg:
          - "Swap is already configured with {{ current_swap_mb }}MB"
          - "No action needed (minimum: {{ swap_minimum_mb }}MB)"
      when: current_swap_mb | int >= swap_minimum_mb
      tags: [swap, validate]

    - name: Update system swappiness (optional optimization)
      sysctl:
        name: vm.swappiness
        value: '10'
        state: present
        reload: yes
      when: current_swap_mb | int >= swap_minimum_mb or swap_enabled is changed
      tags: [swap]