# ── Build ───────────────────────────────────────────────────
FROM rust:1-bookworm AS build
WORKDIR /app

# Cache deps: copy manifests, build a stub, then the real source.
COPY Cargo.toml Cargo.lock ./
RUN mkdir src && echo "fn main() {}" > src/main.rs \
    && cargo build --release \
    && rm -rf src

COPY . .
# Touch so cargo rebuilds with the real main.rs.
RUN touch src/main.rs && cargo build --release

# ── Runtime ─────────────────────────────────────────────────
FROM debian:bookworm-slim AS runtime
WORKDIR /app
RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates \
    && rm -rf /var/lib/apt/lists/*
COPY --from=build /app/target/release/shoplist-backend /usr/local/bin/shoplist-backend
EXPOSE 8080
CMD ["shoplist-backend"]