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

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
# shellcheck disable=SC1091
source "$SCRIPT_DIR/pd_backup_lib.sh"

metrics_dir="${RESTORE_VERIFY_METRICS_DIR:-/mnt/tank/docker/metrics/node-exporter}"
metrics_file="$metrics_dir/pd_restore_verification.prom"
start_epoch="$(date +%s)"
status=1

mkdir -p "$metrics_dir"

previous_success_epoch() {
  if [[ -f "$metrics_file" ]]; then
    awk '/^pd_restore_verification_last_success_timestamp_seconds /{print $2}' "$metrics_file" | tail -n 1
  else
    echo 0
  fi
}

write_metrics() {
  local end_epoch duration last_success tmp
  end_epoch="$(date +%s)"
  duration="$((end_epoch - start_epoch))"
  last_success="$(previous_success_epoch)"
  if [[ "$status" -eq 0 ]]; then
    last_success="$end_epoch"
  fi
  tmp="${metrics_file}.tmp"
  cat > "$tmp" <<EOF
# HELP pd_restore_verification_success Last PD restore verification result (1=success, 0=failure).
# TYPE pd_restore_verification_success gauge
pd_restore_verification_success $(( status == 0 ? 1 : 0 ))
# HELP pd_restore_verification_last_run_timestamp_seconds Unix timestamp of the last PD restore verification run.
# TYPE pd_restore_verification_last_run_timestamp_seconds gauge
pd_restore_verification_last_run_timestamp_seconds $end_epoch
# HELP pd_restore_verification_last_success_timestamp_seconds Unix timestamp of the last successful PD restore verification run.
# TYPE pd_restore_verification_last_success_timestamp_seconds gauge
pd_restore_verification_last_success_timestamp_seconds $last_success
# HELP pd_restore_verification_duration_seconds Duration of the last PD restore verification run in seconds.
# TYPE pd_restore_verification_duration_seconds gauge
pd_restore_verification_duration_seconds $duration
EOF
  mv "$tmp" "$metrics_file"
}

trap write_metrics EXIT

"$SCRIPT_DIR/pd_restore_verify_postgres.sh"
"$SCRIPT_DIR/pd_restore_verify_appdata.sh"

status=0
echo "PD restore verification run complete."