name: Nightly Candidate

on:
  pull_request:
    branches: [main]

permissions:
  contents: read

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: Detect nightly pin changes
        id: nightly
        env:
          BASE_SHA: ${{ github.event.pull_request.base.sha }}
          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
        run: |
          if git diff --quiet "$BASE_SHA" "$HEAD_SHA" -- nightly.nix; then
            echo "changed=false" >>"$GITHUB_OUTPUT"
          else
            echo "changed=true" >>"$GITHUB_OUTPUT"
          fi
      - if: steps.nightly.outputs.changed == 'true'
        uses: DeterminateSystems/nix-installer-action@v13
      - name: Build nightly compatibility suite
        if: steps.nightly.outputs.changed == 'true'
        run: nix build .#legacyPackages.x86_64-linux.nightlyChecks.all --accept-flake-config