## Multi-stage Dockerfile for Next.js app (suitable for Hugging Face Spaces Docker runtime)
# - Builder stage installs deps and builds the Next app
# - Runner stage copies build artifacts and runs `npm run start` on $PORT (default 3000)

FROM node:18-bullseye-slim AS builder
WORKDIR /app

# install OS build deps required by some native node modules and package manager
# copy lockfile first to leverage Docker layer caching
COPY package*.json ./
COPY pnpm-lock.yaml ./

# Install minimal build tools for native modules (node-gyp) and install pnpm.
# Using the repo's `pnpm-lock.yaml` keeps installs deterministic on Spaces.
ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get update \
	&& apt-get install -y --no-install-recommends ca-certificates python3 build-essential git curl \
	&& rm -rf /var/lib/apt/lists/* \
	&& npm install -g pnpm@latest \
	&& pnpm install --frozen-lockfile

# copy source and build
COPY . ./
RUN npm run build

FROM node:18-bullseye-slim AS runner
WORKDIR /app

ENV NODE_ENV=production

# minimal packages for certificates (if needed by model download / https)
RUN apt-get update && apt-get install -y ca-certificates --no-install-recommends && rm -rf /var/lib/apt/lists/*

# copy runtime artifacts from builder
COPY --from=builder /app/package*.json ./
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/.next ./.next
COPY --from=builder /app/public ./public
COPY --from=builder /app/next.config.mjs ./next.config.mjs

# Expose a common port (informational). Hugging Face Spaces will inject $PORT at runtime
# and the CMD below ensures Next listens on that port. Do not hardcode PORT here.
EXPOSE 3000

# If you use private/gated HF models, set HF_TOKEN in the Space secrets and expose here
# e.g. in Space settings: add secret HF_TOKEN with your token

# Ensure `next start` uses the $PORT provided by the Spaces runtime. We use a shell
# wrapper so the environment variable is expanded at container runtime.
CMD ["sh", "-c", "npm run start -- -p ${PORT:-3000}"]