FROM node:20-alpine AS builder
WORKDIR /app
COPY backend/package*.json backend/
# Use npm ci if a lockfile exists in backend, otherwise fall back to npm install
RUN sh -c 'if [ -f backend/package-lock.json ] || [ -f backend/npm-shrinkwrap.json ]; then npm ci --prefix backend --production; else npm install --prefix backend --production; fi'
COPY backend/ backend/
RUN npm run build --prefix backend

FROM node:20-alpine
WORKDIR /app
COPY --from=builder /app/backend/dist ./dist
COPY backend/package*.json ./
RUN npm ci --production --prefix /app
EXPOSE 4000
CMD ["node", "./dist/index.js"]