clean_branches.yml

name: Cleanup old nightly branches

on:
  schedule:
    - cron: "0 3 * * *"   # runs daily at 3am UTC
  workflow_dispatch:

permissions:
  contents: write

jobs:
  cleanup:
    runs-on: ubuntu-latest

    steps:
      - name: Check out repo
        uses: actions/checkout@v4

      - name: Install GitHub CLI
        run: |
          sudo apt-get update
          sudo apt-get install gh -y

      - name: Delete nightly branches older than 7 days
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          set -e

          CUTOFF_DATE=$(date -d "7 days ago" +%s)
          echo "Cutoff timestamp: $CUTOFF_DATE"

          # paginate through all branches
          gh api repos/${{ github.repository }}/branches --paginate -q '.[].name' | while read branch; do
            if [[ "$branch" == nightly/* ]]; then
              echo "Checking $branch..."

              # skip if PR is open for this branch
              PR_COUNT=$(gh pr list --head "$branch" --state open --json number -q 'length')
              if [ "$PR_COUNT" -gt 0 ]; then
                echo "Skipping $branch (open PR exists)"
                continue
              fi

              # get last commit date
              COMMIT_DATE=$(gh api repos/${{ github.repository }}/commits/$branch -q '.commit.committer.date')
              COMMIT_TS=$(date -d "$COMMIT_DATE" +%s)

              if [ "$COMMIT_TS" -lt "$CUTOFF_DATE" ]; then
                echo "Deleting $branch (last commit: $COMMIT_DATE)"
                git push origin --delete "$branch"
              else
                echo "Keeping $branch (recent)"
              fi
            fi
          done