labeler.yml

---
name: "Pull Request Labeler"
'on':
  pull_request_target:
    types: [opened, synchronize, reopened, edited]
permissions: read-all

jobs:
  labeler:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    outputs:
      labels: ${{ steps.labeler.outputs.all-labels }}
    steps:
      - name: Label the PR
        id: labeler
        uses: actions/labeler@v5
        with:
          repo-token: ${{ secrets.GITHUB_TOKEN }}
          sync-labels: true
  title-prefix-checker:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    needs: labeler
    steps:
      - name: Check the PR title prefix
        id: check-prefix
        env:
          title: ${{ github.event.pull_request.title }}
          labels: ${{ needs.labeler.outputs.labels }}
        shell: python
        run: |
          import os
          import re
          import sys
          title = os.environ['title']
          labels = os.environ['labels']
          tags = {
              "infrastructure": "Infrastructure",
              "common": "Common",
              "alice3": "ALICE3",
              "pwgcf": "PWGCF",
              "pwgdq": "PWGDQ",
              "pwgem": "PWGEM",
              "pwghf": "PWGHF",
              "pwgje": "PWGJE",
              "pwglf": "PWGLF",
              "pwgud": "PWGUD",
              "dpg": "DPG",
              "trigger": "Trigger",
              "tutorial": "Tutorial",
          }
          print(f'PR title: "{title}"')
          print(f'PR labels: "{labels}"')
          tags_relevant = [tags[label] for label in tags if label in labels.split(",")]
          print("Relevant title tags:", ",".join(tags_relevant))
          passed = True
          prefix_good = ",".join(tags_relevant)
          prefix_good = f"[{prefix_good}] "
          print(f"Generated prefix: {prefix_good}")
          replace_title = 0
          title_new = title
          # If there is a prefix which contains a known tag, check it for correct tags, and reformat it if needed.
          # If there is a prefix which does not contain any known tag, add the tag prefix.
          # If there is no prefix, add the tag prefix.
          if match := re.match(r"\[?(\w[\w, /\+-]+)[\]:]+ ", title):
              prefix_title = match.group(1)
              words_prefix_title = prefix_title.replace(",", " ").replace("/", " ").split()
              title_stripped = title[len(match.group()) :]
              print(f'PR title prefix: "{prefix_title}" -> tags: {words_prefix_title}')
              print(f'Stripped PR title: "{title_stripped}"')
              if any(tag in words_prefix_title for tag in tags.values()):
                  for tag in tags.values():
                      if tag in tags_relevant and tag not in words_prefix_title:
                          print(f'::error::Relevant tag "{tag}" not found in the prefix of the PR title.')
                          passed = False
                      if tag not in tags_relevant and tag in words_prefix_title:
                          print(f'::error::Irrelevant tag "{tag}" found in the prefix of the PR title.')
                          passed = False
                  # Format a valid prefix.
                  if passed:
                      prefix_good = ",".join(w for w in prefix_title.replace(",", " ").split() if w)
                      prefix_good = f"[{prefix_good}] "
                      print(f"::notice::Reformatted prefix: {prefix_good}")
                      if match.group() != prefix_good:
                          replace_title = 1
                          title_new = prefix_good + title_stripped
              else:
                  print("::warning::No known tags found in the prefix.")
                  if tags_relevant:
                      replace_title = 1
                      title_new = prefix_good + title
          else:
              print("::warning::No valid prefix found in the PR title.")
              if tags_relevant:
                  replace_title = 1
                  title_new = prefix_good + title
          if not passed:
              print("::error::Problems were found in the PR title prefix.")
              print('::notice::Use the form "tags: title" or "[tags] title".')
              sys.exit(1)
          if replace_title:
              print("::warning::The PR title prefix with tags needs to be added or adjusted.")
              print(f'::warning::New title: "{title_new}".')
          else:
              print("::notice::The PR title prefix is fine.")
          with open(os.environ["GITHUB_OUTPUT"], "a", encoding="utf-8") as fh:
              print(f"replace={replace_title}", file=fh)
              print(f"title={title_new}", file=fh)
      - name: Fix the PR title prefix
        if: ${{ steps.check-prefix.outputs.replace == 1 }}
        uses: the-wright-jamie/Update-PR-Info-Action@v1.1.0
        with:
          repo-token: "${{ secrets.GITHUB_TOKEN }}"
          base-branch-regex: master
          error-on-fail: false
          title-template: "${{ steps.check-prefix.outputs.title }}"
          title-update-action: replace