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: ./server
      HLINT_BASE_URL: https://dl.haskellworks.io/binaries/hlint
      HLINT_VERSION: 3.1.6
      HLINT_ARCH: x86_64
      HLINT_OS: linux
      HLINT_URL: $HLINT_BASE_URL/hlint-${HLINT_VERSION}-${HLINT_ARCH}-${HLINT_OS}.tar.gz
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0

      - name: Download hlint
        working-directory: ${{env.working-directory}}
        run: |
          echo "Downloading from ${{env.HLINT_URL}}"
          curl "${{env.HLINT_URL}}" -o "./hlint-${{env.HLINT_VERSION}}-${{env.HLINT_ARCH}}-${{env.HLINT_OS}}.tar.gz"
          tar -zxvf "./hlint-${{env.HLINT_VERSION}}-${{env.HLINT_ARCH}}-${{env.HLINT_OS}}.tar.gz" -C "."

      - name: Run hlint
        shell: bash
        run: |
          CHANGED_HS_FILES=$(git diff --name-only origin/${{github.base_ref}}...${{github.sha}} -- "${{env.working-directory}}/*.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 ${{env.working-directory}}/hlint --no-exit-code --json --hint=${{env.working-directory}}/.hlint.yaml | jq -r "$JQ_SCRIPT" | tee $OUT
            test -z "$(grep -E '^::error' $OUT)"
          fi