name: Cache maintenance

# GitHub keeps 10 GB of Actions caches per repository. The platform dependency
# trees are large (the Windows Tauri tree alone is ~1.6 GB), so unused scopes
# evict the caches the CI jobs restore - which silently turns every run into a
# cold build. This job keeps the budget visible and drops the scopes that can
# never be restored again: pull requests that are already closed or merged.
#
# It runs weekly and on demand. It never touches branch or tag scopes, so the
# caches the release path depends on are safe.
on:
  schedule:
    # Monday 03:17 UTC: after the weekend, before the working week.
    - cron: '17 3 * * 1'
  workflow_dispatch:

permissions:
  actions: write # required to delete caches
  contents: read

concurrency:
  group: cache-maintenance
  cancel-in-progress: false

jobs:
  report:
    name: Report and prune caches
    runs-on: ubuntu-latest
    timeout-minutes: 15
    steps:
      - uses: actions/checkout@v4
        with:
          submodules: false

      - name: Report cache usage and prune dead pull request scopes
        env:
          GH_TOKEN: ${{ github.token }}
          REPO: ${{ github.repository }}
          LIMIT_GB: '8'
        working-directory: openless-all/app
        run: bash scripts/ci-cache-usage.sh --prune --repo "$REPO" --limit-gb "$LIMIT_GB"