#!/bin/sh
set -eu

if [ "$#" -ne 1 ]; then
  echo "Usage: $0 ABSOLUTE_BACKUP_DIRECTORY" >&2
  exit 2
fi

case "$1" in
  /*) ;;
  *) echo "Backup directory must be an absolute path" >&2; exit 2 ;;
esac

backup_root=${1%/}
stamp=$(date -u +%Y%m%dT%H%M%SZ)
target="$backup_root/$stamp"
if [ -e "$target" ]; then
  echo "Backup target already exists: $target" >&2
  exit 1
fi
mkdir -p "$target"
chmod 700 "$target"
export BACKUP_DIRECTORY="$backup_root"

env_file=${COMPOSE_ENV_FILE:-.env.production}
compose="docker compose --env-file $env_file -f compose.production.yaml"
$compose exec -T db sh -c 'pg_dump --format=custom --no-owner --no-acl -U "$POSTGRES_USER" -d "$POSTGRES_DB"' > "$target/postgres.dump"
$compose run --rm --entrypoint /bin/sh storage-tool -c 'mc alias set local http://minio:9000 "$S3_ACCESS_KEY" "$S3_SECRET_KEY" >/dev/null && mc stat "local/$S3_BUCKET" >/dev/null && mc mirror --overwrite "local/$S3_BUCKET" "/backup/'"$stamp"'/minio" && chmod -R a+rwX "/backup/'"$stamp"'/minio"'
tar -czf "$target/minio.tar.gz" -C "$target" minio
rm -rf "$target/minio"
(cd "$target" && sha256sum postgres.dump minio.tar.gz > SHA256SUMS)
chmod 600 "$target/postgres.dump" "$target/minio.tar.gz" "$target/SHA256SUMS"
echo "Backup created: $target"