FROM node:18-alpine

WORKDIR /app

# Copy package files
COPY backend/package*.json ./

# Install dependencies
RUN npm install --production --no-audit --no-fund && \
    if [ ! -d node_modules/express ]; then echo "ERROR: express not installed" && exit 1; fi

# Copy application code
COPY backend/src ./src
COPY frontend ./frontend

EXPOSE 4001

CMD ["node", "src/server.js"]