#!/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}"

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

mkdir -p "${BACKUP_DIR}"
: "${POSTGRES_HOST:=postgres}"
: "${POSTGRES_PORT:=5432}"
if [ -z "${POSTGRES_DB:-}" ] || [ -z "${POSTGRES_USER:-}" ] || [ -z "${POSTGRES_PASSWORD:-}" ]; then
  echo "POSTGRES_DB, POSTGRES_USER, and POSTGRES_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="${POSTGRES_PASSWORD}" pg_dump \
  -h "${POSTGRES_HOST}" \
  -p "${POSTGRES_PORT}" \
  -U "${POSTGRES_USER}" \
  -d "${POSTGRES_DB}" \
  -Fc \
  > "${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}/documents" "${uploads_backup_dir}/photos"
if [ -f "${UPLOAD_DIR}/homepage.md" ] && [ ! -f "${uploads_backup_dir}/homepage.md" ]; then
  cp "${UPLOAD_DIR}/homepage.md" "${uploads_backup_dir}/homepage.md"
fi
if [ -d "${UPLOAD_DIR}/documents" ]; then
  cp -an "${UPLOAD_DIR}/documents/." "${uploads_backup_dir}/documents/"
fi
if [ -d "${UPLOAD_DIR}/photos" ]; then
  cp -an "${UPLOAD_DIR}/photos/." "${uploads_backup_dir}/photos/"
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)"