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

namespace='{{ matrix_healthcheck_namespace }}'
backup_root='{{ matrix_healthcheck_backup_path }}'
max_backup_age_seconds=$(({{ matrix_healthcheck_backup_max_age_hours }} * 3600))
warn_percent='{{ matrix_healthcheck_warn_percent }}'
critical_percent='{{ matrix_healthcheck_critical_percent }}'
status=ok
messages=()

set_status() {
  local next="$1"
  case "$next" in
    critical) status=critical ;;
    warning) [[ "$status" != critical ]] && status=warning ;;
  esac
}

if ! k3s kubectl get namespace "$namespace" >/dev/null 2>&1; then
  set_status critical
  messages+=("namespace $namespace is unavailable")
else
  unready=$(k3s kubectl -n "$namespace" get pods --no-headers 2>/dev/null | awk '$2 !~ /^[0-9]+\/[0-9]+$/ || $3 != "Running" {print $1}')
  if [[ -n "$unready" ]]; then
    set_status critical
    messages+=("unready pods: ${unready//$'\n'/, }")
  fi
fi

usage=$(df -P / | awk 'NR == 2 {gsub(/%/, "", $5); print $5}')
if (( usage >= critical_percent )); then
  set_status critical
  messages+=("root filesystem usage ${usage}%")
elif (( usage >= warn_percent )); then
  set_status warning
  messages+=("root filesystem usage ${usage}%")
fi

latest=$(find "$backup_root" -mindepth 1 -maxdepth 1 -type d -name '20*Z' -printf '%T@ %p\n' 2>/dev/null | sort -nr | awk 'NR == 1 {print $1, $2}')
if [[ -z "$latest" ]]; then
  set_status critical
  messages+=("no Matrix backup exists")
else
  latest_epoch=${latest%% *}
  latest_path=${latest#* }
  age=$(( $(date +%s) - ${latest_epoch%.*} ))
  if (( age > max_backup_age_seconds )); then
    set_status critical
    messages+=("latest Matrix backup is ${age}s old")
  elif [[ ! -f "$latest_path/SHA256SUMS" || ! -f "$latest_path/manifest.json" ]]; then
    set_status critical
    messages+=("latest Matrix backup is incomplete")
  fi
fi

printf '{"service":"matrix_k3s","status":"%s","messages":[' "$status"
for i in "${!messages[@]}"; do
  (( i > 0 )) && printf ','
  printf '"%s"' "${messages[$i]//\"/\\\"}"
done
printf '],"root_usage_percent":%s}\n' "$usage"