#!/usr/bin/env bash
# Restore one trusted application dump into a disposable, local-only PG16 server.
set -euo pipefail
umask 077
[[ $EUID == 0 && $# == 1 && -f $1 ]] || exit 64
dump=$(readlink -f "$1")
bin=/usr/lib/postgresql/16/bin
stage=$(mktemp -d /var/tmp/atlas-application-restore.XXXXXXXX)
started=$(date +%s)
cleanup() {
  if [[ -f $stage/data/postmaster.pid ]]; then
    runuser -u postgres -- "$bin/pg_ctl" -D "$stage/data" -m immediate -w stop >/dev/null 2>&1 || true
  fi
  rm -rf -- "$stage"
}
trap cleanup EXIT
chown postgres:postgres "$stage"
install -o postgres -g postgres -m 0600 "$dump" "$stage/input.dump"
exec 2>"$dump.restore-error.txt"
runuser -u postgres -- "$bin/initdb" -D "$stage/data" -A trust --no-locale >"$stage/init.log"
runuser -u postgres -- "$bin/pg_ctl" -D "$stage/data" -l "$stage/server.log" \
  -o "-k $stage -p 55433 -c listen_addresses=''" -w start >/dev/null
runuser -u postgres -- "$bin/createdb" -h "$stage" -p 55433 restore_check
timeout 1800 runuser -u postgres -- "$bin/pg_restore" --exit-on-error --no-owner --no-privileges \
  -h "$stage" -p 55433 -d restore_check "$stage/input.dump"
tables=$(runuser -u postgres -- "$bin/psql" -XAt -h "$stage" -p 55433 -d restore_check \
  -c "SELECT count(*) FROM pg_tables WHERE schemaname NOT IN ('pg_catalog','information_schema')")
[[ $tables =~ ^[0-9]+$ && $tables -gt 0 ]]
printf 'verified_utc=%s\nelapsed_seconds=%s\napplication_tables=%s\nmethod=isolated_pg16_restore_without_role_acl_replay\n' \
  "$(date -u +%FT%TZ)" "$(( $(date +%s) - started ))" "$tables" >"$dump.RESTORE_CHECK"
cat "$dump.RESTORE_CHECK"