#!/usr/bin/env bash
# Copies Printhive's data out of Docker's named volumes into ./data, for the
# switch to host folders. Run it on the server, from the folder holding
# docker-compose.yml, with the stack stopped.
#
# It only copies: the named volumes are left exactly as they were, so if
# anything looks wrong you can put the old docker-compose.yml back and start
# again with nothing lost.
set -euo pipefail

# Same settings Compose uses, so the copy lands where the stack will look.
if [ -f .env ]; then
  DATA_DIR="${DATA_DIR:-$(grep -E '^DATA_DIR=' .env | tail -1 | cut -d= -f2-)}"
  PGDATA_DIR="${PGDATA_DIR:-$(grep -E '^PGDATA_DIR=' .env | tail -1 | cut -d= -f2-)}"
fi
DATA_DIR="${DATA_DIR:-./data}"
PGDATA_DIR="${PGDATA_DIR:-./data/pgdata}"
VOLUMES=(pgdata uploads thumbnails glb extracted)

# Where each volume's contents should end up.
target_for() {
  case "$1" in
    pgdata) echo "$PGDATA_DIR" ;;
    *) echo "$DATA_DIR/$1" ;;
  esac
}

# Compose names volumes "<project>_<name>", the project being this folder's name
# unless it's set elsewhere.
PROJECT="${COMPOSE_PROJECT_NAME:-$(basename "$(pwd)")}"

if docker compose ps --status running --quiet 2>/dev/null | grep -q .; then
  echo "Printhive is still running. Stop it first:  docker compose down" >&2
  exit 1
fi

echo "Project:  $PROJECT"
echo "Files:    $DATA_DIR"
echo "Database: $PGDATA_DIR"
echo

for name in "${VOLUMES[@]}"; do
  volume="${PROJECT}_${name}"
  target="$(target_for "$name")"

  if ! docker volume inspect "$volume" >/dev/null 2>&1; then
    echo "· $volume — no such volume, skipping (nothing to copy)"
    mkdir -p "$target"
    continue
  fi
  if [ -d "$target" ] && [ -n "$(ls -A "$target" 2>/dev/null)" ]; then
    echo "· $target already has files in it — skipping, so nothing is overwritten" >&2
    continue
  fi

  mkdir -p "$target"
  # -a keeps ownership and timestamps, which Postgres's data folder needs.
  docker run --rm \
    -v "$volume":/from:ro \
    -v "$(cd "$(dirname "$target")" && pwd)/$(basename "$target")":/to \
    alpine sh -c 'cp -a /from/. /to/'
  echo "· $volume → $target ($(du -sh "$target" | cut -f1))"
done

echo
echo "Done. Start it up again with:  docker compose up -d"
echo "Once you're happy, the old volumes can be removed with:"
for name in "${VOLUMES[@]}"; do echo "  docker volume rm ${PROJECT}_${name}"; done