#!/usr/bin/env bash
# Nightly backup: a dated dump of the database, and a mirror of the model files.
#
# Run it from anywhere — it finds the folder holding docker-compose.yml itself.
# Printhive keeps running throughout; pg_dump takes a consistent snapshot.
#
#   ./tools/backup.sh
#
# Settings (in .env beside docker-compose.yml, or the environment):
#   BACKUP_DIR  where backups go        (default: ./backups)
#   UPLOADS_DIR the model files          (default: asked of the running container)
#   KEEP_DAYS   dumps to keep, in days  (default: 14)
set -euo pipefail

cd "$(dirname "$0")/.."

# A setting from the environment, else from .env, else the fallback. Tolerates
# "export NAME=", quotes, spaces and Windows line endings.
setting() { # name, fallback
  local from_env="${!1:-}"
  if [ -n "$from_env" ]; then echo "$from_env"; return; fi
  if [ -f .env ]; then
    local line
    line="$(tr -d '\r' < .env \
      | grep -E "^[[:space:]]*(export[[:space:]]+)?$1[[:space:]]*=" \
      | tail -1 | cut -d= -f2- \
      | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' -e 's/^"\(.*\)"$/\1/' -e "s/^'\(.*\)'$/\1/")"
    if [ -n "$line" ]; then echo "$line"; return; fi
  fi
  echo "$2"
}

BACKUP_DIR="$(setting BACKUP_DIR ./backups)"
KEEP_DAYS="$(setting KEEP_DAYS 14)"
stamp="$(date +%Y-%m-%d)"

# Where the model files really are: ask the running container, rather than
# trusting a setting that may have drifted from how the stack was deployed.
UPLOADS_DIR="${UPLOADS_DIR:-}"
if [ -z "$UPLOADS_DIR" ]; then
  UPLOADS_DIR="$(docker inspect printhive-app \
    --format '{{range .Mounts}}{{if eq .Destination "/app/uploads"}}{{.Source}}{{end}}{{end}}' 2>/dev/null || true)"
fi
if [ -z "$UPLOADS_DIR" ]; then
  echo "$(date '+%F %T') FAILED: couldn’t find where /app/uploads comes from — is printhive-app running?" >&2
  exit 1
fi

echo "$(date '+%F %T') files: $UPLOADS_DIR → backups: $BACKUP_DIR"

# A path the container can see but this machine can't (a stack manager deploying
# from inside a container does that) would back up nothing at all.
if [ ! -d "$UPLOADS_DIR" ]; then
  echo "$(date '+%F %T') FAILED: $UPLOADS_DIR isn’t reachable from here — set UPLOADS_DIR to its path on this machine" >&2
  exit 1
fi
if [ -z "$(ls -A "$UPLOADS_DIR" 2>/dev/null)" ]; then
  echo "$(date '+%F %T') FAILED: $UPLOADS_DIR is empty — refusing to mirror nothing over a good backup" >&2
  exit 1
fi

mkdir -p "$BACKUP_DIR/db"

# --- the database -----------------------------------------------------------
# Written to a .part file first, so an interrupted run never leaves behind
# something that looks like a good backup.
# An empty library where backups already exist means something is wrong with
# the stack, not that you deleted everything: don't write that over good ones.
models="$(docker compose exec -T db psql -U printhive -d printhive -tAc 'select count(*) from models' 2>/dev/null | tr -d '[:space:]' || true)"
if [ "$models" = "0" ] && ls "$BACKUP_DIR"/db/printhive-*.dump >/dev/null 2>&1; then
  echo "$(date '+%F %T') FAILED: the database has no models, but older backups do — leaving them alone" >&2
  exit 1
fi

dump="$BACKUP_DIR/db/printhive-$stamp.dump"

# Dumped inside the container and read back there — a dump that can't be listed
# is no backup at all, and pg_restore can only list a real file, not a pipe.
if ! docker compose exec -T db sh -c \
    'pg_dump -U printhive -Fc printhive > /tmp/printhive.dump && pg_restore -l /tmp/printhive.dump > /dev/null'; then
  echo "$(date '+%F %T') FAILED: couldn’t dump the database — keeping the old backups" >&2
  docker compose exec -T db rm -f /tmp/printhive.dump || true
  exit 1
fi
docker compose exec -T db cat /tmp/printhive.dump > "$dump.part"
docker compose exec -T db rm -f /tmp/printhive.dump || true

if [ ! -s "$dump.part" ]; then
  echo "$(date '+%F %T') FAILED: the dump came out empty — keeping the old backups" >&2
  rm -f "$dump.part"
  exit 1
fi
mv "$dump.part" "$dump"
echo "$(date '+%F %T') database → $dump ($(du -h "$dump" | cut -f1))"

# Older dumps go, so the folder doesn't grow for ever.
find "$BACKUP_DIR/db" -name 'printhive-*.dump' -type f -mtime "+$KEEP_DAYS" -delete

# --- the model files --------------------------------------------------------
# A mirror, not a history: it matches what's there now, deletions included.
# Thumbnails, previews and extracted archives are left out — they rebuild.
rsync -a --delete "$UPLOADS_DIR/" "$BACKUP_DIR/uploads/"
echo "$(date '+%F %T') files    → $BACKUP_DIR/uploads ($(du -sh "$BACKUP_DIR/uploads" | cut -f1))"