name: Update `flake.lock`
on:
  workflow_dispatch:
  schedule:
    - cron: '0 0 * * 0' # runs weekly on Sunday at 00:00

jobs:
  update_lockfile:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
      - name: Install nix
        uses: DeterminateSystems/nix-installer-action@main
      - name: Restore and cache Nix store
        uses: nix-community/cache-nix-action@v5
        with:
          # restore and save a cache using this key
          primary-key: nix-${{ runner.os }}-${{ hashFiles('**/*.nix') }}
          # if there's no cache hit, restore a cache by this prefix
          restore-prefixes-first-match: nix-${{ runner.os }}-
          # collect garbage until Nix store size (in bytes) is at most this number
          # before trying to save a new cache
          gc-max-store-size-linux: 1073741824
          # do purge caches
          purge: true
          # purge all versions of the cache
          purge-prefixes: cache-${{ runner.os }}-
          # created more than this number of seconds ago relative to the start of the `Post Restore` phase
          purge-created: 0
          # except the version with the `primary-key`, if it exists
          purge-primary-key: never
      - name: Update flake.lock
        uses: DeterminateSystems/update-flake-lock@main
        with:
          # inputs: dzgui dzgui-testing # We'll see whether I want to limit the updates to dzgui
          token: ${{ secrets.GH_TOKEN_FOR_UPDATES }}
          pr-title: "Update flake.lock"
          pr-assignees: jiriks74
          pr-labels: |
            flake.lock
            automated
      - name: Print PR number
        run: echo Pull request number is ${{ steps.update.outputs.pull-request-number }}.