#!/usr/bin/env bash
#
# One-command backup of a Provenance deployment: the Postgres database and the
# MinIO object store, into a single timestamped bundle under ./backups/.
#
#   ./backup.sh                 # write backups/provenance-backup-<UTC>.tar
#   BACKUP_RETAIN_DAYS=30 ./backup.sh   # also prune bundles older than 30 days
#
# Run it from the host where `docker compose` manages the stack (i.e. this
# deploy/ directory). Restore steps are in BACKUP.md.
set -euo pipefail

cd "$(dirname "$0")"  # the deploy/ directory (where docker-compose.yml lives)

# Config comes from the compose .env (same file the stack uses); fall back to
# the compose defaults so a vanilla stack still backs up.
if [ -f .env ]; then set -a; . ./.env; set +a; fi
PGUSER="${POSTGRES_USER:-provenance}"
PGDB="${POSTGRES_DB:-provenance}"

dc() { docker compose "$@"; }

ts="$(date -u +%Y%m%dT%H%M%SZ)"
work="backups/.work-$ts"
mkdir -p "$work" backups

cleanup() { rm -rf "$work"; }
trap cleanup EXIT

echo "→ Dumping Postgres database '$PGDB'…"
dc exec -T postgres pg_dump -U "$PGUSER" -d "$PGDB" --no-owner --clean --if-exists \
  | gzip > "$work/db.sql.gz"

echo "→ Archiving MinIO object store…"
# Tar MinIO's data directory straight from the container (objects + bucket
# metadata). Restored by extracting back into the miniodata volume.
dc exec -T minio tar czf - -C /data . > "$work/minio-data.tar.gz"

cat > "$work/MANIFEST.txt" <<EOF
Provenance backup
created:   $ts
database:  $PGDB  (pg_dump --clean --if-exists, gzip)
objects:   MinIO /data (tar.gz)
restore:   see deploy/BACKUP.md
EOF

bundle="backups/provenance-backup-$ts.tar"
# Contents are already gzipped, so the outer archive is a plain tar.
tar cf "$bundle" -C "$work" db.sql.gz minio-data.tar.gz MANIFEST.txt

echo "✓ Backup written: $bundle ($(du -h "$bundle" | cut -f1))"

if [ -n "${BACKUP_RETAIN_DAYS:-}" ]; then
  echo "→ Pruning bundles older than ${BACKUP_RETAIN_DAYS} days…"
  find backups -maxdepth 1 -name 'provenance-backup-*.tar' -type f \
    -mtime "+${BACKUP_RETAIN_DAYS}" -print -delete
fi