name: Lint new PR

on:
    pull_request:
        types: [opened]

jobs:
    check-description:
        name: Check that PR has description
        runs-on: ubuntu-20.04

        steps:
            - name: Check if PR is shame-worthy
              id: is-shame-worthy
              run: |
                  FILTERED_BODY=$( \
                      sed -r -e \
                      '/^(\.\.\.)|(\*)|(#+ )|(- )|(<!--)|(👉)/d' \
                      <<< $RAW_BODY \
                  )
                  echo "::debug::Filtered PR body to $FILTERED_BODY"
                  if [[ -z "${FILTERED_BODY//[[:space:]]/}" ]]; then
                      echo "is-shame-worthy=true" >> $GITHUB_OUTPUT
                  else
                      echo "is-shame-worthy=false" >> $GITHUB_OUTPUT
                  fi
              env:
                  RAW_BODY: ${{ github.event.pull_request.body }}

            - name: Shame if PR has no description
              if: steps.is-shame-worthy.outputs.is-shame-worthy == 'true'
              run: |
                  SHAME_BODY="Hey @${{ github.actor }}! 👋\nThis pull request seems to contain no description. Please add useful context, rationale, and/or any other information that will help make sense of this change now and in the distant Mars-based future."
                  curl -s -u posthog-bot:${{ secrets.POSTHOG_BOT_GITHUB_TOKEN || secrets.GITHUB_TOKEN }} -X POST -d "{ \"body\": \"$SHAME_BODY\" }" "https://api.github.com/repos/${{ github.repository }}/issues/${{ github.event.pull_request.number }}/comments"