name: Cleanup Cache

on:
  pull_request:
    types:
      - closed

jobs:
  cleanup:
    runs-on: ubuntu-latest
    steps:
      - name: Check out code
        uses: actions/checkout@v3
        
      - name: Cleanup
        run: |
          gh extension install actions/gh-actions-cache
          
          REPO=${{ github.repository }}
          BRANCH="refs/pull/${{ github.event.pull_request.number }}/merge"

          while true
          do
            cacheKeysForPR=$(gh actions-cache list -R $REPO -B $BRANCH -L 100 | cut -f 1 )

            if [ -z "$cacheKeysForPR" ]
            then
              break
            fi

            ## Setting this to not fail the workflow while deleting cache keys. 
            set +e
            for cacheKey in $cacheKeysForPR
            do
              gh actions-cache delete $cacheKey -R $REPO -B $BRANCH --confirm
            done
          done
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}