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: https://github.com/DeterminateSystems/nix-installer-action@main
      - name: Setup Action cache for nix
        uses: https://github.com/DeterminateSystems/magic-nix-cache-action@main
        with:
          fail-mode: true

      - name: Update flake.lock
        id: update
        run: |
          nix flake update 2>&1 | awk '
            /^• Updated input/ {in_update = 1; print; next}
            in_update && !/^warning:/ {print}
            /^$/ {in_update = 0}
          ' | tee update.log
          echo "update_log=$(cat update.log)" >> $GITHUB_OUTPUT
          rm update.log

      - name: Create Pull Request
        id: create-pull-request
        uses: https://code.forgejo.org/peter-evans/create-pull-request@main
        with:
            token: ${{ secrets.FORGEJO_TOKEN_FOR_UPDATES  }}
            commit-message: Update `flake.lock`
            title: Update `flake.lock`
            body: |
              - The following Nix Flake inputs were updated

              ```
              ${{ steps.update.outputs.update_log }}
              ```
  
              Auto-generated by [update.yml][1] with the help of
              [create-pull-request][2]
  
              [1]: https://forgejo.stefka.eu/jiriks74/update-flake-lock
              [2]: https://github.com/peter-evans/create-pull-request
            branch: update-flake-lock
      - name: Print PR number
        run: echo Pull request number is ${{ steps.create-pull-request.outputs.pull-request-number }}.