name: Backport PR on Label

on:
  pull_request_target:
    types:
      - labeled

# Permissions needed for the korthout/backport-action to create branches and PRs
permissions:
  contents: write
  pull-requests: write

jobs:
  backport:
    name: Create Backport PR
    runs-on: ubuntu-latest
    if: |
      github.event.pull_request.merged == true && startsWith(github.event.label.name, 'backport-')
    steps:
      - uses: actions/checkout@v5
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          token: ${{ steps.app-token.outputs.token }}

      - name: Backport Action
        uses: korthout/backport-action@v3
        with:
          # Regex pattern for labels that should trigger a backport AND extracts the target branch
          # from the name (e.g. v0.x or v0.x.y; we use zerover). This action will ONLY proceed if
          # the label that triggered the workflow fully matches this pattern.
          # Example matching labels: "backport-v0.1", "backport-v0.10.1"
          # Example non-matching labels: "backport-foo", "backport-v1.0"
          label_pattern: '^backport-(v0\.\d+(\.\d+)?)$'