#!/usr/bin/env sh
set -eu

BACKUP_DIR="${BACKUP_DIR:-./data/backups}"
RETENTION_DAYS="${BACKUP_RETENTION_DAYS:-14}"
UPLOAD_DIR="${UPLOAD_DIR:-/app/uploads}"
PROMPT_DIR="${PROMPT_DIR:-/app/prompts}"
DATABASE_DRIVER="${DATABASE__DRIVER:-postgres}"
DATABASE_HOST="${DATABASE__HOST:-postgres}"
DATABASE_PORT="${DATABASE__PORT:-5432}"
DATABASE_NAME="${DATABASE__DATABASE:-}"
DATABASE_USER="${DATABASE__USER:-}"
DATABASE_PASSWORD="${DATABASE__PASSWORD:-}"

timestamp="$(date -u +%Y%m%d-%H%M%S)"
postgres_file="postgres-${timestamp}.dump"
manifest_file="backup-${timestamp}.manifest"

mkdir -p "${BACKUP_DIR}"
if [ "${DATABASE_DRIVER}" != "postgres" ]; then
  echo "create_postgres_backup.sh requires DATABASE__DRIVER=postgres." >&2
  exit 1
fi
if [ -z "${DATABASE_NAME}" ] || [ -z "${DATABASE_USER}" ] || [ -z "${DATABASE_PASSWORD}" ]; then
  echo "DATABASE__DATABASE, DATABASE__USER, and DATABASE__PASSWORD must be set." >&2
  exit 1
fi
if ! command -v pg_dump >/dev/null 2>&1; then
  echo "pg_dump is not installed in this environment." >&2
  exit 1
fi
PGPASSWORD="${DATABASE_PASSWORD}" pg_dump \
  -h "${DATABASE_HOST}" \
  -p "${DATABASE_PORT}" \
  -U "${DATABASE_USER}" \
  -d "${DATABASE_NAME}" \
  -Fc \
  > "${BACKUP_DIR}/${postgres_file}"

cat > "${BACKUP_DIR}/${manifest_file}" <<EOF
created_at_utc=${timestamp}
postgres_dump=${postgres_file}
backup_dir=${BACKUP_DIR}
uploads_backup_dir=${BACKUP_DIR}/uploads
prompts_backup_dir=${BACKUP_DIR}/prompts
EOF

find "${BACKUP_DIR}" -type f \( \
  -name 'postgres-*.dump' -o \
  -name 'backup-*.manifest' \
\) -mtime +"${RETENTION_DAYS}" -delete

uploads_backup_dir="${BACKUP_DIR}/uploads"
mkdir -p "${uploads_backup_dir}"
if [ -d "${UPLOAD_DIR}" ]; then
  cp -an "${UPLOAD_DIR}/." "${uploads_backup_dir}/"
fi

prompts_backup_dir="${BACKUP_DIR}/prompts"
mkdir -p "${prompts_backup_dir}"
if [ -d "${PROMPT_DIR}" ]; then
  cp -a "${PROMPT_DIR}/." "${prompts_backup_dir}/"
fi

echo "Created backup set:"
echo "  ${BACKUP_DIR}/${postgres_file}"
echo "  ${BACKUP_DIR}/${manifest_file}"
echo "  ${uploads_backup_dir}/ (incremental uploads mirror)"
echo "  ${prompts_backup_dir}/ (prompts mirror)"