name: Nightly rustfmt
on:
  schedule:
    - cron: "0 0 * * *" # runs daily at 00:00 UTC
  workflow_dispatch: # allows manual triggering

permissions: {}

jobs:
  format:
    name: Nightly rustfmt
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    steps:
      - uses: actions/checkout@v4
        with:
          ref: main
      - name: Get flake hash
        id: flake-hash
        run: echo "hash=$(sha256sum flake.lock | cut -d' ' -f1 | cut -c1-8)" >> $GITHUB_OUTPUT
      - name: Install Nix
        uses: DeterminateSystems/nix-installer-action@v17
      - name: Nix Cache
        uses: DeterminateSystems/magic-nix-cache-action@main
        with:
          diagnostic-endpoint: ""
          use-flakehub: false
      - name: Rust Cache
        uses: Swatinem/rust-cache@v2
        with:
          shared-key: "nightly-${{ steps.flake-hash.outputs.hash }}"
      - name: Run Nightly rustfmt
        run: |
          nix develop -i -L .#nightly --command bash -c '
            # Force use of Nix-provided rustfmt
            export RUSTFMT=$(command -v rustfmt)
            cargo fmt
          '
          # Manually remove trailing whitespace
          find . -name '*.rs' -type f -exec sed -E -i 's/[[:space:]]+$//' {} +
      - name: Get the current date
        run: echo "date=$(date +'%Y-%m-%d')" >> $GITHUB_ENV
      - name: Create Pull Request
        uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e # v7.0.8
        env:
          PRE_COMMIT_ALLOW_NO_CONFIG: 1
        with:
          token: ${{ secrets.BACKPORT_TOKEN }}
          author: Fmt Bot <bot@cashudevkit.org>
          title: Automated nightly rustfmt (${{ env.date }})
          body: |
            Automated nightly `rustfmt` changes by [create-pull-request](https://github.com/peter-evans/create-pull-request) GitHub action
          commit-message: ${{ env.date }} automated rustfmt nightly
          labels: rustfmt
          branch: automated-rustfmt-${{ env.date }}