name: publish-release-artifacts

on:
  release:
    types:
      - created

jobs:
  publish-release-artifacts:
    runs-on: ubuntu-latest
    if: startsWith(github.ref, 'refs/tags/')

    steps:
      - name: Checkout
        uses: actions/checkout@v2

      - name: Archive
        env:
          RELEASE_SIGNING_KEY: ${{ secrets.RELEASE_SIGNING_KEY }}
          RELEASE_SIGNING_KEY_PASSPHRASE: ${{ secrets.RELEASE_SIGNING_KEY_PASSPHRASE }}
        run: |
          # compute file name
          export TAG="$(echo "$GITHUB_REF" | sed -n 's_^refs/tags/__p')"
          if [ -z "$TAG" ]; then
            echo "action must be run on a tag. GITHUB_REF is not a tag: $GITHUB_REF"
            exit 1
          fi
          # Attempt to extract "1.2.3" from "v1.2.3" to maintain artifact name backwards compat.
          # Otherwise, degrade to using full tag.
          export VERSION="$(echo "$TAG" | sed 's_^v\([0-9]\+\.[0-9]\+\.[0-9]\+\)$_\1_')"
          export ZSTD_VERSION="zstd-$VERSION"

          # archive
          git archive $TAG \
              --prefix $ZSTD_VERSION/ \
              --format tar \
              -o $ZSTD_VERSION.tar

          # Do the rest of the work in a sub-dir so we can glob everything we want to publish.
          mkdir artifacts/
          mv $ZSTD_VERSION.tar artifacts/
          cd artifacts/

          # compress
          zstd -k -19 $ZSTD_VERSION.tar
          gzip -k  -9 $ZSTD_VERSION.tar

          # we only publish the compressed tarballs
          rm $ZSTD_VERSION.tar

          # hash
          sha256sum $ZSTD_VERSION.tar.zst > $ZSTD_VERSION.tar.zst.sha256
          sha256sum $ZSTD_VERSION.tar.gz  > $ZSTD_VERSION.tar.gz.sha256

          # sign
          if [ -n "$RELEASE_SIGNING_KEY" ]; then
            export GPG_BATCH_OPTS="--batch --no-use-agent --pinentry-mode loopback --no-tty --yes"
            echo "$RELEASE_SIGNING_KEY" | gpg $GPG_BATCH_OPTS --import
            gpg $GPG_BATCH_OPTS --armor --sign --sign-with signing@zstd.net --detach-sig --passphrase "$RELEASE_SIGNING_KEY_PASSPHRASE" --output $ZSTD_VERSION.tar.zst.sig $ZSTD_VERSION.tar.zst
            gpg $GPG_BATCH_OPTS --armor --sign --sign-with signing@zstd.net --detach-sig --passphrase "$RELEASE_SIGNING_KEY_PASSPHRASE" --output $ZSTD_VERSION.tar.gz.sig  $ZSTD_VERSION.tar.gz
          fi

      - name: Publish
        uses: skx/github-action-publish-binaries@release-1.3
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          args: artifacts/*
