name: Update contributors

on:
  push:
    branches: [main]
  schedule:
    # GitHub's contributors API is cached and lags a merge by up to ~24h, so a
    # weekly pass catches anyone the push-triggered run was too early to see.
    - cron: '17 4 * * 1'
  workflow_dispatch:

# Only one run at a time; a burst of merges must not race on README.md.
concurrency:
  group: update-contributors
  cancel-in-progress: false

jobs:
  update:
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - uses: actions/checkout@v4
        with:
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Regenerate the contributor wall
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: python3 tools/update-contributors.py

      - name: Commit if it changed
        run: |
          git config user.name "mukul975"
          git config user.email "mukuljangra5@gmail.com"
          git add README.md
          if git diff --staged --quiet; then
            echo "No new contributors."
            exit 0
          fi
          git commit -m "chore: update contributor wall"
          # Another workflow (update-index) may have pushed while this ran.
          git pull --rebase --autostash origin main
          git push