#!/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"

BEFORE_FILE=""
exit_code=0

usage() {
  printf 'Usage: %s [--before-file <df_output_file>]\n' "$(basename "$0")"
}

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

require_cmd df || exit 1

section "Post-Cleanup Disk Space"
df -h 2>&1 | tee -a "$LOG_FILE"

section "Post-Cleanup Inodes"
df -i 2>&1 | tee -a "$LOG_FILE" || warning "Unable to collect inode usage"

section "Critical Filesystem Check"
while read -r fs size used avail pct mount; do
  percent="$(usage_percent_number "$pct")"
  if (( percent >= EMERGENCY_THRESHOLD )); then
    critical "$mount is still ${pct} full on $fs (size=$size used=$used avail=$avail)"
    exit_code=1
  elif (( percent >= CRIT_THRESHOLD )); then
    warning "$mount remains high at ${pct} on $fs"
  else
    ok "$mount is ${pct} full on $fs"
  fi
done < <(df -P -h | awk 'NR > 1 { print $1, $2, $3, $4, $5, $6 }')

if [[ -n "$BEFORE_FILE" ]]; then
  section "Before And After Comparison"
  if [[ ! -f "$BEFORE_FILE" ]]; then
    warning "Before file not found: $BEFORE_FILE"
  else
    awk '
      NR == FNR && FNR > 1 {
        before[$6] = $5
        next
      }
      FNR > 1 {
        mount = $6
        if (mount in before) {
          before_pct = before[mount]
          after_pct = $5
          gsub(/%/, "", before_pct)
          gsub(/%/, "", after_pct)

          if (after_pct < before_pct) {
            status = "OK"
            result = "improved"
          } else if (after_pct == before_pct) {
            status = "WARNING"
            result = "unchanged"
          } else {
            status = "WARNING"
            result = "increased"
          }

          printf "%s: %s before=%s after=%s (%s)\n", status, mount, before[mount], $5, result
        }
      }
    ' "$BEFORE_FILE" <(df -P -h) | tee -a "$LOG_FILE"
  fi
else
  warning "No --before-file supplied. Improvement comparison skipped."
fi

if [[ "$exit_code" -eq 0 ]]; then
  ok "Post-check completed without emergency-threshold filesystems."
else
  critical "One or more filesystems remain at or above ${EMERGENCY_THRESHOLD}%."
fi

exit "$exit_code"