name: Check flake
on:
  push:
    branches: [main]
    path:
      - ./**.nix
      - ./flake.lock
  pull_request:
  schedule:
    - cron: 5 4 * * 5 # At 04:05 on Friday.

jobs:
  check:
    runs-on: ubuntu-22.04
    steps:
      - uses: actions/checkout@v4
      - uses: DeterminateSystems/nix-installer-action@v9
      - if: ${{ github.event_name != 'pull_request' }} # Do not cache pull requests
        uses: DeterminateSystems/magic-nix-cache-action@v3
      - name: Run `nix flake check`
        run: nix flake check
  lockfile:
    runs-on: ubuntu-22.04
    needs: check
    if: ${{ github.event_name == 'schedule' }} # only run when scheduled
    steps:
      - uses: actions/checkout@v4
      - uses: DeterminateSystems/nix-installer-action@v9
      - uses: DeterminateSystems/update-flake-lock@v20
      - name: Run `nix flake check`
        run: nix flake check
  build-documentation:
    runs-on: ubuntu-latest
    if: ${{ github.event_name != 'schedule' }} # only run when not scheduled
    steps:
    - uses: actions/checkout@v4
    - uses: DeterminateSystems/nix-installer-action@v9
    - uses: DeterminateSystems/magic-nix-cache-action@v3
    - name: Build documentation
      run: nix build .#docs --print-build-logs
    - name: Upload artifact
      uses: actions/upload-pages-artifact@v1
      with:
        path: ./result
  deploy:
    runs-on: ubuntu-latest
    needs: build-documentation
    if: ${{ github.ref == 'main' }} # only run on main branch
    permissions:
      pages: write
      id-token: write
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    steps:
      - name: Deploy to GitHub Pages
        id: deployment
        uses: actions/deploy-pages@v2