name: server lint
on:
  label:
  pull_request:
    paths:
      - "server/**"

jobs:
  hlint:
    runs-on: ubuntu-20.04
    if: "!contains(github.event.pull_request.labels.*.name, 'ignore-server-hlint-checks') && github.event.label.name != 'ignore-server-hlint-checks'"
    env:
      working-directory: .
      HLINT_BASE_URL: https://github.com/ndmitchell/hlint/releases/download
      HLINT_ARCH: x86_64
      HLINT_OS: linux

    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0

      - name: Download hlint
        run: |
          HLINT_VERSION="$(jq -r '.hlint' ./server/VERSIONS.json)"
          HLINT_URL="${{env.HLINT_BASE_URL}}/v${HLINT_VERSION}/hlint-${HLINT_VERSION}-${{env.HLINT_ARCH}}-${{env.HLINT_OS}}.tar.gz"
          echo "Downloading from ${HLINT_URL}"
          curl --fail --location --output "./hlint.tar.gz" "${HLINT_URL}"
          tar xvf \
            hlint.tar.gz \
            --directory='.' \
            --strip-components=1 \
            "hlint-${HLINT_VERSION}/hlint"

      - name: Run hlint
        shell: bash
        run: |
          CHANGED_HS_FILES=$(git diff --name-only origin/${{github.base_ref}}...${{github.sha}} -- "./*.hs" | xargs -i -d '\n' sh -c 'ls -d {} 2>/dev/null || true')
          echo "$CHANGED_HS_FILES"
          JQ_SCRIPT='.[] | "::" + (if (.severity=="Warning" or .severity=="Error") then "error" else "warning" end) + " file=\(.file),line=\(.startLine),col=\(.startColumn)::\(.severity):" + " \(.hint)%0AFound:%0A  \(.from | gsub("\n";"%0A  "))%0A" + try ("Perhaps:%0A  " + (.to | gsub("\n";"%0A  ")) + "%0A") catch "" + try (if .note | length > 0 then "Note:%0A  " + (.note | join("\n") | gsub("\n";"%0A  ")) else "" end) catch ""'
          if [[ "$CHANGED_HS_FILES" ]]
          then
            OUT=$(mktemp)
            echo "$CHANGED_HS_FILES" | xargs ${{env.working-directory}}/hlint --no-exit-code --json --hint=./.hlint.yaml | jq -r "$JQ_SCRIPT" | tee $OUT
            test -z "$(grep -E '^::error' $OUT)"
          fi