#!/usr/bin/env bash
set -o errexit
set -o nounset
set -o pipefail

section() {
  printf '\n== %s ==\n' "$1"
}

run_optional() {
  local description="$1"
  shift

  if "$@"; then
    return 0
  fi
  printf 'WARNING: %s failed\n' "$description"
  return 0
}

section "Operating system"
if [[ -r /etc/os-release ]]; then
  run_optional "OS release report" cat /etc/os-release
else
  printf 'WARNING: /etc/os-release is unavailable\n'
fi
run_optional "kernel report" uname -a

section "Host"
run_optional "hostname report" hostname
run_optional "uptime report" uptime

section "CPU and virtualization"
if command -v lscpu >/dev/null 2>&1; then
  run_optional "CPU report" lscpu
  printf '\nVirtualization flags:\n'
  lscpu | grep -E 'Virtualization|Hypervisor vendor' || \
    printf 'INFO: no virtualization summary reported by lscpu\n'
else
  printf 'WARNING: lscpu is unavailable\n'
fi
if grep -Eqm1 '(^|[[:space:]])(vmx|svm)([[:space:]]|$)' /proc/cpuinfo; then
  printf 'OK: CPU virtualization flags detected\n'
else
  printf 'WARNING: CPU virtualization flags were not detected\n'
fi

section "Memory"
if command -v free >/dev/null 2>&1; then
  run_optional "memory report" free -h
else
  run_optional "memory report" cat /proc/meminfo
fi

section "Disks"
if command -v lsblk >/dev/null 2>&1; then
  run_optional "block device report" lsblk -o NAME,TYPE,SIZE,FSTYPE,MOUNTPOINTS,MODEL
else
  printf 'WARNING: lsblk is unavailable\n'
fi
run_optional "filesystem report" df -hT

section "Network"
if command -v ip >/dev/null 2>&1; then
  run_optional "network interface report" ip -brief address
  run_optional "route report" ip route
else
  printf 'WARNING: ip is unavailable\n'
fi

section "Firmware and Secure Boot"
if [[ -d /sys/firmware/efi ]]; then
  printf 'OK: boot mode is UEFI\n'
else
  printf 'INFO: boot mode appears to be legacy BIOS\n'
fi
if command -v mokutil >/dev/null 2>&1; then
  run_optional "Secure Boot report" mokutil --sb-state
else
  printf 'INFO: mokutil is unavailable; Secure Boot state not queried\n'
fi

section "IOMMU"
if [[ -r /proc/cmdline ]]; then
  printf 'Kernel command line:\n'
  cat /proc/cmdline
  if grep -Eq '(^|[[:space:]])(intel_iommu=on|amd_iommu=on|iommu=)' /proc/cmdline; then
    printf 'OK: IOMMU-related kernel arguments detected\n'
  else
    printf 'INFO: no explicit IOMMU kernel argument detected\n'
  fi
fi
if command -v dmesg >/dev/null 2>&1; then
  dmesg 2>/dev/null | grep -Ei 'DMAR|IOMMU|AMD-Vi' | tail -n 30 || \
    printf 'INFO: no readable IOMMU hints found in dmesg\n'
fi

section "NVIDIA hardware"
if command -v lspci >/dev/null 2>&1; then
  lspci -nn | grep -i nvidia || printf 'INFO: no NVIDIA PCI devices detected\n'
else
  printf 'INFO: lspci is unavailable\n'
fi

section "Existing platform components"
for command_name in docker virsh cockpit-bridge; do
  if command -v "$command_name" >/dev/null 2>&1; then
    printf 'OK: %s is installed at %s\n' "$command_name" "$(command -v "$command_name")"
  else
    printf 'INFO: %s is not installed\n' "$command_name"
  fi
done
if command -v systemctl >/dev/null 2>&1; then
  for unit in docker.service libvirtd.service cockpit.socket; do
    if systemctl cat "$unit" >/dev/null 2>&1; then
      state="$(systemctl is-active "$unit" 2>/dev/null || true)"
      printf 'INFO: %-20s state=%s\n' "$unit" "${state:-unknown}"
    else
      printf 'INFO: %s is not installed\n' "$unit"
    fi
  done
fi

printf '\nOK: preflight completed without modifying the host\n'