#!/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"

usage() {
  printf 'Usage: %s --fs <filesystem>\n' "$(basename "$0")"
}

while [[ "$#" -gt 0 ]]; do
  case "$1" in
    --fs)
      FILESYSTEM="${2:-}"
      shift 2
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      critical "Unknown argument: $1"
      usage
      exit 2
      ;;
  esac
done

if [[ -z "$FILESYSTEM" ]]; then
  critical "Missing required --fs <filesystem>"
  usage
  exit 2
fi

missing=0
for cmd in mmgetstate mmlscluster mmlsfs mmlsdisk mmlsmount mmlsmgr df; do
  require_cmd "$cmd" || missing=1
done

if [[ "$missing" -ne 0 ]]; then
  exit 2
fi

issues=0

section "GPFS daemon state"
state_output="$(mmgetstate -a 2>&1 || true)"
printf '%s\n' "$state_output" | tee -a "$LOG_FILE"
if printf '%s\n' "$state_output" | awk 'NR > 1 && $0 !~ / active / { found=1 } END { exit found ? 0 : 1 }'; then
  warning "Not all GPFS nodes appear active"
fi

section "Target filesystem definition"
if mmlsfs "$FILESYSTEM" 2>&1 | tee -a "$LOG_FILE"; then
  ok "Filesystem exists: $FILESYSTEM"
else
  critical "Filesystem does not exist or cannot be queried: $FILESYSTEM"
  exit 1
fi

section "Target filesystem mount state"
mount_output="$(mmlsmount "$FILESYSTEM" 2>&1 || true)"
printf '%s\n' "$mount_output" | tee -a "$LOG_FILE"
if printf '%s\n' "$mount_output" | grep -Eiq 'not mounted|no file systems were found|not found'; then
  warning "Filesystem may not be mounted anywhere: $FILESYSTEM"
fi

section "Existing disks"
if ! mmlsdisk "$FILESYSTEM" 2>&1 | tee -a "$LOG_FILE"; then
  critical "Unable to list disks for filesystem: $FILESYSTEM"
  issues=1
fi

section "Filesystem capacity"
df -h 2>&1 | awk -v fs="$FILESYSTEM" 'NR == 1 || $0 ~ fs || $0 ~ /gpfs|mmfs/' | tee -a "$LOG_FILE"

section "Cluster health"
if command -v mmhealth >/dev/null 2>&1; then
  health_output="$(mmhealth cluster show 2>&1 || true)"
  printf '%s\n' "$health_output" | tee -a "$LOG_FILE"
  if printf '%s\n' "$health_output" | grep -Eiq 'degraded|failed|down|error|unhealthy'; then
    warning "Cluster health output indicates a degraded condition"
  fi
else
  warning "mmhealth command not available, skipping health check"
fi

section "Managers and quorum"
mmlsmgr 2>&1 | tee -a "$LOG_FILE" || {
  critical "Unable to query GPFS manager/quorum information"
  issues=1
}

if [[ "$issues" -eq 0 ]]; then
  ok "Precheck completed for filesystem: $FILESYSTEM"
  exit 0
fi

critical "Precheck found operational validation failures"
exit 1