FROM --platform=$BUILDPLATFORM tonistiigi/xx:1.6.1 AS xx

FROM --platform=$BUILDPLATFORM golang:alpine as gobuild

RUN apk add clang lld

COPY --from=xx / /

ARG TARGETPLATFORM
ARG BUILD_TAGS
ARG GOPROXY
ARG TARGETOS
ARG TARGETARCH
ARG LDFLAGS

ENV CGO_ENABLED=1

# install build tools.
RUN xx-apk add --no-cache gcc g++ musl-dev git

WORKDIR /src

# download modules.
COPY src/go.mod src/go.sum .
RUN --mount=type=cache,target=/go/pkg \
  go mod download

# build Hugo.
COPY src .
RUN --mount=type=cache,target=/go/pkg \
  --mount=type=cache,target=/root/.cache/go-build,id=go-pkg-$TARGETPLATFORM \
  if [[ -z "$BUILD_TAGS" ]]; \
  then \
    xx-go build -ldflags="$LDFLAGS" -o /usr/bin/hugo; \
  else \
    xx-go build -ldflags="$LDFLAGS" -tags $BUILD_TAGS -o /usr/bin/hugo; \
  fi

FROM alpine as dart-sass

ARG TARGETARCH

RUN apk add jq curl
RUN curl -s https://api.github.com/repos/sass/dart-sass/releases/latest | \
    jq -r --arg REGEXP "^.+-linux-${TARGETARCH/amd64/x64}-musl.tar.gz$" '.assets[].browser_download_url | match($REGEXP) | .string' | \
    xargs -n1 curl -L -o dart-sass.tar.gz
RUN tar -C /opt -xzf dart-sass.tar.gz

FROM golang:alpine as builder

COPY --from=gobuild /usr/bin/hugo /usr/bin/hugo