---
# playbooks/preflight/gather_hardware_facts.yml
#
# Purpose:
#   Gather comprehensive hardware specifications from Proxmox hosts for
#   capacity planning and topology analysis (e.g., Docker Swarm 3-node cluster)
#
# Usage:
#   ansible-playbook -i inventory/hosts.ini playbooks/preflight/gather_hardware_facts.yml \
#     -e "target_hosts=proxmox_cluster" \
#     -e "output_file=hardware_comparison_$(date +%Y%m%d).yml"
#
# Modules Explained:
#   - ansible.builtin.gather_facts: Collects system facts (CPU, RAM, network, OS)
#     WHY: Native, zero-install, idempotent. Beats shell commands because it's structured.
#   - ansible.builtin.setup: Explicit fact-gathering (redundant but explicit docs)
#   - ansible.builtin.command: For Proxmox-specific queries (pvesh, pveversion)
#     WHY: Cleaner than shell for simple commands; no shell interpretation risk
#   - ansible.builtin.copy: Save structured YAML report locally
#     WHY: Idempotent, checksummed, handles permissions correctly
#
# Idempotency:
#   All tasks are read-only (gather facts, query status). No state changes.
#   Safe to run multiple times without side effects.
#
# Safety Notes:
#   - Does NOT modify Proxmox configuration or cluster state
#   - Requires root SSH access (standard Proxmox assumption)
#   - Network scanning is passive (no stress-testing)

- name: "Gather Hardware Facts from Proxmox Hosts"
  hosts: "{{ target_hosts | default('proxmox_cluster') }}"
  gather_facts: true
  become: true
  vars:
    output_dir: "{{ playbook_dir }}/../../outputs"
    output_file: "{{ output_dir }}/hardware_facts_{{ ansible_date_time.iso8601_basic_short }}.yml"

  pre_tasks:
    - name: "Validate target hosts are Proxmox nodes"
      ansible.builtin.assert:
        that:
          - inventory_hostname.startswith('pve')
        fail_msg: "This playbook is for Proxmox nodes (pve*). Target: {{ inventory_hostname }}"
      tags:
        - validate

    - name: "Ensure output directory exists"
      ansible.builtin.file:
        path: "{{ output_dir }}"
        state: directory
        mode: '0755'
      delegate_to: localhost
      run_once: true
      tags:
        - setup

  tasks:
    # -------------------------------------------------------------------------
    # SECTION 1: SYSTEM & OS FACTS
    # -------------------------------------------------------------------------

    - name: "1.1 Gather all facts (native Ansible)"
      ansible.builtin.setup:
      tags:
        - facts
        - always

    - name: "1.2 Extract CPU model and frequencies"
      ansible.builtin.set_fact:
        hw_cpu_model: "{{ ansible_processor | first | default('unknown') }}"
        hw_cpu_cores: "{{ ansible_processor_vcpus | default('unknown') }}"
        hw_cpu_cores_per_socket: "{{ ansible_processor_cores | default('unknown') }}"
        hw_cpu_count: "{{ ansible_processor_count | default(1) }}"
      tags:
        - facts
        - cpu

    - name: "1.3 Query CPU frequency (max freq)"
      ansible.builtin.shell: "grep 'cpu MHz' /proc/cpuinfo | head -1"
      register: _cpu_freq_output
      changed_when: false
      failed_when: false
      tags:
        - facts
        - cpu

    - name: "1.4 Parse CPU frequency"
      ansible.builtin.set_fact:
        hw_cpu_freq_mhz: "{{ (_cpu_freq_output.stdout | regex_search(':\\s+([0-9.]+)') | regex_replace('[^0-9.]', '')).split('.')[0] | float if _cpu_freq_output.stdout else 'unknown' }}"
      tags:
        - facts
        - cpu

    - name: "1.5 Extract RAM information"
      ansible.builtin.set_fact:
        hw_ram_total_mb: "{{ ansible_memtotal_mb | default('unknown') }}"
        hw_ram_free_mb: "{{ ansible_memfree_mb | default('unknown') }}"
      tags:
        - facts
        - ram

    - name: "1.6 Extract OS and kernel"
      ansible.builtin.set_fact:
        hw_os_family: "{{ ansible_os_family }}"
        hw_os_distro: "{{ ansible_distribution }}"
        hw_os_release: "{{ ansible_distribution_release }}"
        hw_kernel: "{{ ansible_kernel }}"
        hw_uptime_seconds: "{{ ansible_uptime_seconds }}"
      tags:
        - facts
        - os

    # -------------------------------------------------------------------------
    # SECTION 2: STORAGE FACTS
    # -------------------------------------------------------------------------

    - name: "2.1 Gather disk information"
      ansible.builtin.set_fact:
        hw_disks: "{{ ansible_devices | default({}) | dict2items | map(attribute='key') | list }}"
      tags:
        - facts
        - storage

    - name: "2.2 Gather mount points and usage"
      ansible.builtin.shell: |
        df -h | tail -n +2 | awk '{print $1 " (" $4 " available of " $2 ")"}'
      register: _mount_output
      changed_when: false
      tags:
        - facts
        - storage

    - name: "2.3 Parse mount data"
      ansible.builtin.set_fact:
        hw_mounts: "{{ _mount_output.stdout_lines | default([]) }}"
      tags:
        - facts
        - storage

    # -------------------------------------------------------------------------
    # SECTION 3: NETWORK FACTS
    # -------------------------------------------------------------------------

    - name: "3.1 Gather network interface details"
      ansible.builtin.set_fact:
        hw_network_interfaces: "{{ ansible_interfaces | default([]) }}"
      tags:
        - facts
        - network

    # -----------------------------------------------------------------------
    # SECTION 4: PROXMOX-SPECIFIC FACTS
    # -----------------------------------------------------------------------

    - name: "4.1 Query Proxmox version"
      ansible.builtin.command: "pveversion"
      register: _pveversion_output
      changed_when: false
      tags:
        - facts
        - proxmox

    - name: "4.2 Parse Proxmox version"
      ansible.builtin.set_fact:
        hw_proxmox_version: "{{ _pveversion_output.stdout | regex_search('proxmox-ve\\s+([0-9.]+)') | regex_replace('[^0-9.]', '') }}"
        hw_pveversion_full: "{{ _pveversion_output.stdout }}"
      tags:
        - facts
        - proxmox

    - name: "4.3 Query Proxmox cluster status"
      ansible.builtin.command: "pvesh get /cluster/resources --output-format json"
      register: _cluster_resources
      changed_when: false
      failed_when: false
      tags:
        - facts
        - proxmox

    - name: "4.4 Count VMs and containers on this host"
      ansible.builtin.set_fact:
        hw_vm_count: "{{ (_cluster_resources.stdout | from_json | selectattr('node', 'equalto', inventory_hostname) | selectattr('type', 'match', 'qemu|lxc') | list | length) if _cluster_resources.rc == 0 else 'unknown' }}"
      tags:
        - facts
        - proxmox

    - name: "4.5 Query Proxmox cluster info"
      ansible.builtin.command: "pvesh get /cluster/status --output-format json"
      register: _cluster_status
      changed_when: false
      failed_when: false
      tags:
        - facts
        - proxmox

    - name: "4.6 Parse cluster membership"
      ansible.builtin.set_fact:
        hw_cluster_name: "{{ (_cluster_status.stdout | from_json | first).cluster | default('not-clustered') if _cluster_status.rc == 0 and (_cluster_status.stdout | from_json | length) > 0 else 'not-clustered' }}"
        hw_cluster_nodes: "{{ (_cluster_status.stdout | from_json | map(attribute='name') | list) if _cluster_status.rc == 0 else [] }}"
      tags:
        - facts
        - proxmox

    - name: "4.7 Check if node is clustered"
      ansible.builtin.set_fact:
        hw_is_clustered: "{{ inventory_hostname in hw_cluster_nodes }}"
      tags:
        - facts
        - proxmox

    # -----------------------------------------------------------------------
    # SECTION 5: SYSTEM LOAD & CAPACITY
    # -----------------------------------------------------------------------

    - name: "5.1 Gather system load"
      ansible.builtin.set_fact:
        hw_load_1min: "{{ ansible_load | default([0, 0, 0]) | first }}"
        hw_load_5min: "{{ (ansible_load | default([0, 0, 0]))[1] }}"
        hw_load_15min: "{{ (ansible_load | default([0, 0, 0]))[2] }}"
      tags:
        - facts
        - load

    - name: "5.2 Calculate CPU usage percentage"
      ansible.builtin.set_fact:
        hw_cpu_load_percent: "{{ ((hw_load_1min | float / hw_cpu_cores | int) * 100) | int if hw_load_1min != 0 else 0 }}"
      tags:
        - facts
        - load

  post_tasks:
    - name: "Build hardware summary fact"
      ansible.builtin.set_fact:
        hardware_summary:
          hostname: "{{ inventory_hostname }}"
          ip_address: "{{ ansible_default_ipv4.address }}"
          fqdn: "{{ ansible_fqdn }}"
          timestamp: "{{ ansible_date_time.iso8601 }}"
          
          system:
            os: "{{ hw_os_distro }} {{ hw_os_release }}"
            kernel: "{{ hw_kernel }}"
            uptime_days: "{{ (hw_uptime_seconds / 86400) | int }}"
          
          cpu:
            model: "{{ hw_cpu_model }}"
            sockets: "{{ hw_cpu_count }}"
            cores_per_socket: "{{ hw_cpu_cores_per_socket }}"
            total_cores: "{{ hw_cpu_cores }}"
            max_frequency_mhz: "{{ hw_cpu_freq_mhz | int if hw_cpu_freq_mhz != 'unknown' else 'unknown' }}"
            current_1min_load: "{{ hw_load_1min }}"
            cpu_load_percent: "{{ hw_cpu_load_percent }}%"
          
          memory:
            total_mb: "{{ hw_ram_total_mb }}"
            total_gb: "{{ (hw_ram_total_mb | int / 1024) | int if hw_ram_total_mb != 'unknown' else 'unknown' }}"
            free_mb: "{{ hw_ram_free_mb }}"
            free_gb: "{{ (hw_ram_free_mb | int / 1024) | int if hw_ram_free_mb != 'unknown' else 'unknown' }}"
          
          storage:
            disks_detected: "{{ hw_disks | length }}"
            disk_list: "{{ hw_disks }}"
            mounts_summary: "{{ hw_mounts }}"
          
          network:
            interfaces_count: "{{ hw_network_interfaces | length }}"
            interface_list: "{{ hw_network_interfaces }}"
          
          proxmox:
            version: "{{ hw_proxmox_version }}"
            version_full: "{{ hw_pveversion_full }}"
            cluster_name: "{{ hw_cluster_name | default('not-clustered') }}"
            is_clustered: "{{ hw_is_clustered }}"
            cluster_members: "{{ hw_cluster_nodes | default([]) }}"
            vms_and_containers: "{{ hw_vm_count }}"
      tags:
        - summary
        - always

    - name: "Display hardware summary"
      ansible.builtin.debug:
        msg: "{{ hardware_summary }}"
      tags:
        - summary
        - always

    - name: "Collect all hardware facts for report"
      ansible.builtin.set_fact:
        all_hardware_facts: "{{ all_hardware_facts | default({}) | combine({inventory_hostname: hardware_summary}) }}"
      tags:
        - report

    - name: "Write hardware comparison report"
      ansible.builtin.copy:
        content: |
          ---
          # Hardware Facts Report
          # Generated: {{ ansible_date_time.iso8601 }}
          # Hosts Analyzed: {{ groups[target_hosts | default('proxmox_cluster')] | length }}
          #
          # Usage:
          #   This report compares hardware specifications for Docker Swarm topology planning.
          #   See README in documentation/architecture/ for capacity analysis.

          {{ all_hardware_facts | to_nice_yaml }}
        dest: "{{ output_file }}"
        mode: '0644'
      delegate_to: localhost
      run_once: true
      tags:
        - report

    - name: "Report output file location"
      ansible.builtin.debug:
        msg: "✓ Hardware facts saved to: {{ output_file }}"
      delegate_to: localhost
      run_once: true
      tags:
        - report