#!/usr/bin/env bash
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=00_env.sh
. "$SCRIPT_DIR/00_env.sh"

EXCLUDE_MOUNTED=false
EXCLUDE_EXISTING_NSD=false

usage() {
  printf 'Usage: %s [--exclude-mounted] [--exclude-existing-nsd]\n' "$(basename "$0")"
}

while [[ "$#" -gt 0 ]]; do
  case "$1" in
    --exclude-mounted)
      EXCLUDE_MOUNTED=true
      shift
      ;;
    --exclude-existing-nsd)
      EXCLUDE_EXISTING_NSD=true
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      critical "Unknown argument: $1"
      usage
      exit 2
      ;;
  esac
done

for cmd in lsblk findmnt; do
  require_cmd "$cmd" || exit 2
done

warning "Candidate devices are not automatically safe. Confirm every device with the storage and cluster teams before use."

existing_gpfs_devices=""
if [[ "$EXCLUDE_EXISTING_NSD" == "true" ]]; then
  if command -v mmlsnsd >/dev/null 2>&1; then
    existing_gpfs_devices="$(mmlsnsd 2>/dev/null || true)"
  elif command -v mmlsdisk >/dev/null 2>&1; then
    existing_gpfs_devices="$(mmlsdisk all 2>/dev/null || true)"
  else
    warning "mmlsnsd and mmlsdisk are unavailable; cannot exclude existing GPFS devices"
  fi
fi

section "Block device inventory"
lsblk -dpno NAME,TYPE,SIZE,MODEL,SERIAL,MOUNTPOINT 2>&1 | tee -a "$LOG_FILE"

section "Candidate devices"
found=0
while read -r name type size model serial mountpoint; do
  [[ "$type" == "disk" ]] || continue

  if [[ "$EXCLUDE_MOUNTED" == "true" ]]; then
    if [[ -n "${mountpoint:-}" ]] || findmnt -rn --source "$name" >/dev/null 2>&1; then
      continue
    fi
  fi

  if [[ "$EXCLUDE_EXISTING_NSD" == "true" ]] && [[ -n "$existing_gpfs_devices" ]]; then
    if printf '%s\n' "$existing_gpfs_devices" | grep -Fq "$name"; then
      continue
    fi
  fi

  printf 'OK: candidate=%s size=%s model=%s serial=%s mountpoint=%s\n' \
    "$name" "${size:-unknown}" "${model:-unknown}" "${serial:-unknown}" "${mountpoint:-none}" | tee -a "$LOG_FILE"
  found=1
done < <(lsblk -dpno NAME,TYPE,SIZE,MODEL,SERIAL,MOUNTPOINT)

if [[ "$found" -eq 0 ]]; then
  warning "No candidate devices found with the selected filters"
fi