# ── Build stage ────────────────────────────────────────────────────────────────
FROM golang:1.25-alpine AS builder

WORKDIR /build

# Cache dependency downloads separately from source compilation.
COPY go.mod go.sum ./
RUN go mod download

COPY . .

RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 \
    go build -ldflags="-s -w" -o /scraper ./cmd/scraper

# ── single-file binary stage ───────────────────────────────────────────────────
# Download the official pre-compiled single-file-cli binary (Deno-compiled,
# statically linked for Linux x86_64 glibc).  We pin to a specific version so
# image builds are reproducible; bump this ARG to upgrade.
FROM alpine:3.20 AS singlefile-downloader
ARG SINGLEFILE_VERSION=2.0.83
RUN apk add --no-cache wget ca-certificates && \
    wget -q -O /single-file \
      "https://github.com/gildas-lormeau/single-file-cli/releases/download/v${SINGLEFILE_VERSION}/single-file-x86_64-linux" && \
    chmod +x /single-file

# ── Runtime stage ──────────────────────────────────────────────────────────────
FROM alpine:3.20

# ca-certificates: HTTPS to novelfire.net
# gcompat: glibc compatibility shim so the glibc-linked single-file binary
#          runs on musl/Alpine without needing a full glibc image.
# libstdc++: required by the Deno runtime embedded in single-file
RUN apk add --no-cache ca-certificates tzdata gcompat libstdc++

WORKDIR /app

COPY --from=builder /scraper /app/scraper
COPY --from=singlefile-downloader /single-file /usr/local/bin/single-file

# Create the default static output directory.
RUN mkdir -p /app/static/books

# Non-root user.
RUN addgroup -S scraper && adduser -S scraper -G scraper
RUN chown -R scraper:scraper /app
USER scraper

# ── Configuration ─────────────────────────────────────────────────────────────
ENV BROWSERLESS_URL=http://browserless:3030
ENV BROWSERLESS_STRATEGY=content
ENV SCRAPER_WORKERS=0
ENV SCRAPER_STATIC_ROOT=/app/static/books
ENV SCRAPER_HTTP_ADDR=:8080
ENV SINGLEFILE_PATH=/usr/local/bin/single-file

EXPOSE 8080

# Default: run as an HTTP server. Override CMD to use "run" for one-shot.
ENTRYPOINT ["/app/scraper"]
CMD ["serve"]