#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$ROOT_DIR"

set -a
. ./.env
set +a

timestamp="$(date +"%Y%m%d_%H%M%S")"
backup_dir="${1:-$ROOT_DIR/backend/backups/backup_${timestamp}}"
mkdir -p "$backup_dir"

db_dump_path="$backup_dir/db.dump"
media_archive_path="$backup_dir/media.tar.gz"
meta_path="$backup_dir/backup_meta.env"
checksums_path="$backup_dir/SHA256SUMS"

docker compose exec -T db sh -lc "PGPASSWORD='$POSTGRES_PASSWORD' pg_dump -U '$POSTGRES_USER' -d '$POSTGRES_DB' -Fc --no-owner --no-privileges" > "$db_dump_path"
tar -C "$ROOT_DIR/backend" -czf "$media_archive_path" media

cat > "$meta_path" <<EOF
BACKUP_CREATED_AT=$timestamp
POSTGRES_DB=$POSTGRES_DB
POSTGRES_USER=$POSTGRES_USER
DB_DUMP_FILE=$(basename "$db_dump_path")
MEDIA_ARCHIVE_FILE=$(basename "$media_archive_path")
EOF

(
  cd "$backup_dir"
  shasum -a 256 "$(basename "$db_dump_path")" "$(basename "$media_archive_path")" > "$checksums_path"
)

printf '%s\n' "$backup_dir"