name: Prune Unused Branches

permissions:
  contents: read

on:
  pull_request:
    paths:
     - .github/workflows/prune-branches.yml
     - .github/workflows/prune-unused-branches.py

jobs:
  prune-branches:
    name: Prune Branches
    if: github.repository_owner == 'llvm'
    runs-on: ubuntu-24.04
    permissions:
      contents: write
    steps:
      - name: Fetch LLVM sources
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          persist-credentials: true # Relies on persisted credentials to delete unused remote branches
          fetch-depth: 0
      - name: Install dependencies
        run: |
          pip install --require-hashes -r ./llvm/utils/git/requirements.txt
      - name: Run Script
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          mkdir patches
          python3 .github/workflows/prune-unused-branches.py .
      - name: Upload Patches
        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
        with:
          name: BranchDiffs
          retention-days: 90
          path: patches/*.patch
      - name: Upload Branch List
        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
        with:
          name: BranchList
          retention-days: 90
          path: branches.txt