#!/bin/sh
set -eu

usage() {
  echo "usage: $0 --project-name NAME --input FILE --confirm-project NAME" >&2
  exit 2
}

project_name=
input=
confirm_project=
while [ "$#" -gt 0 ]; do
  case "$1" in
    --project-name) project_name=${2-}; shift 2 ;;
    --input) input=${2-}; shift 2 ;;
    --confirm-project) confirm_project=${2-}; shift 2 ;;
    *) usage ;;
  esac
done

[ -n "$project_name" ] && [ -n "$input" ] && [ -n "$confirm_project" ] || usage
[ "$confirm_project" = "$project_name" ] || {
  echo "restore confirmation must match --project-name exactly" >&2
  exit 2
}
[ -r "$input" ] || { echo "backup input is not readable" >&2; exit 2; }

resolve_volume() {
  names=$(docker volume ls \
    --filter "label=com.docker.compose.project=$project_name" \
    --filter "label=com.docker.compose.volume=qdrant-data" \
    --format '{{.Name}}')
  count=$(printf '%s\n' "$names" | sed '/^$/d' | wc -l | tr -d ' ')
  [ "$count" -eq 1 ] || {
    echo "expected exactly one qdrant-data volume for compose project $project_name" >&2
    exit 2
  }
  printf '%s\n' "$names" | sed -n '/./{p;q;}'
}

resolve_mountpoint() {
  mountpoint=$(docker volume inspect --format '{{ .Mountpoint }}' "$1")
  [ -n "$mountpoint" ] || { echo "docker did not return a qdrant-data mountpoint" >&2; exit 2; }
  case "$mountpoint" in
    /*) ;;
    *) echo "qdrant-data mountpoint is not absolute: $mountpoint" >&2; exit 2 ;;
  esac
  [ -d "$mountpoint" ] || { echo "qdrant-data mountpoint is not a directory: $mountpoint" >&2; exit 2; }
  printf '%s\n' "$mountpoint"
}

volume_name=$(resolve_volume)
mountpoint=$(resolve_mountpoint "$volume_name")
running_container=$(docker compose --project-name "$project_name" ps --status running -q qdrant)
restart_qdrant=0
staging_dir=
extract_dir=

cleanup() {
  status=$?
  if [ "$status" -ne 0 ] && [ -n "${staging_dir:-}" ] && [ -d "${staging_dir:-}" ]; then
    find "$mountpoint" -mindepth 1 -maxdepth 1 -exec rm -rf -- {} +
    find "$staging_dir" -mindepth 1 -maxdepth 1 -exec mv {} "$mountpoint"/ \;
  fi
  if [ -n "${staging_dir:-}" ] && [ -d "${staging_dir:-}" ]; then
    rm -rf "$staging_dir"
  fi
  if [ -n "${extract_dir:-}" ] && [ -d "${extract_dir:-}" ]; then
    rm -rf "$extract_dir"
  fi
  if [ "$restart_qdrant" -eq 1 ]; then
    docker compose --project-name "$project_name" start qdrant >/dev/null
  fi
  exit "$status"
}
trap cleanup EXIT HUP INT TERM

if [ -n "$running_container" ]; then
  docker compose --project-name "$project_name" stop qdrant >/dev/null
  restart_qdrant=1
fi

parent_dir=$(dirname "$mountpoint")
staging_dir=$(mktemp -d "$parent_dir/.qdrant-restore-staging.XXXXXX")
extract_dir=$(mktemp -d "${TMPDIR:-/tmp}/qdrant-restore.XXXXXX")
tar -C "$extract_dir" -xf "$input"

find "$mountpoint" -mindepth 1 -maxdepth 1 -exec mv {} "$staging_dir"/ \;
find "$extract_dir" -mindepth 1 -maxdepth 1 -exec mv {} "$mountpoint"/ \;

rm -rf "$staging_dir"
staging_dir=
rm -rf "$extract_dir"
extract_dir=
echo "Qdrant restore completed into $volume_name for compose project $project_name"