name: Auto-merge Dependabot patch PRs

# Strategy:
#   - PATCH updates (x.y.Z) → auto-merge once CI passes (bugfix only, zero risk)
#   - MINOR updates (x.Y.z) → manual review required (kept open as PR)
#   - MAJOR updates         → blocked entirely by dependabot.yml (ignore list)

on:
  pull_request:
    branches: [main]

permissions:
  contents: write
  pull-requests: write

jobs:
  automerge:
    runs-on: ubuntu-latest
    if: github.actor == 'dependabot[bot]'
    steps:
      - name: Fetch Dependabot metadata
        id: meta
        uses: dependabot/fetch-metadata@v2
        with:
          github-token: "${{ secrets.GITHUB_TOKEN }}"

      - name: Auto-merge patch updates
        if: steps.meta.outputs.update-type == 'version-update:semver-patch'
        run: gh pr merge --auto --squash "$PR_URL"
        env:
          PR_URL: ${{ github.event.pull_request.html_url }}
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}