ci.yml

name: CI

on:
  push:
    branches: ["main"]
  pull_request:
    branches: ["main"]

jobs:
  checks:
    runs-on: ubuntu-latest
    steps:
      - name: checkout
        uses: actions/checkout@v4

      - name: Install Nix
        uses: cachix/install-nix-action@v24

      - name: Nix Format Check
        run: nix fmt -- . --check

      - name: Nix Syntax Check
        run: nix flake check

  build-plan:
    # Save some computation. If the checks fail, don't build.
    needs: checks
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.set-matrix.outputs.matrix }}
    steps:
      - name: checkout
        uses: actions/checkout@v4

      - name: Install Nix
        uses: cachix/install-nix-action@v24
        with:
          extra_nix_config: |
            trusted-public-keys = public:O6JLD0yXzaJDPiQW1meVu32JIDViuaPtGDfjlOopU7o= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
            substituters = https://hercules.servers.lowrisc.org/nix-cache/public/ https://cache.nixos.org/

      - name: Build and Cache Attic
        if: github.event_name != 'pull_request'
        run: |
          nix profile install github:zhaofengli/attic#attic
          attic login --set-default lowrisc https://hercules.servers.lowrisc.org/nix-cache/ ${{ secrets.NIX_CACHE_TOKEN }}
          attic push public $(which attic)

      - name: Generate Build Matrix
        id: set-matrix
        run: |
          matrix="$(nix eval --json .#githubActions.matrix)"
          echo "matrix=$matrix" >> $GITHUB_OUTPUT

  build:
    needs: build-plan
    runs-on: ${{ matrix.os }}
    strategy:
      matrix: ${{fromJSON(needs.build-plan.outputs.matrix)}}
    steps:
      - name: checkout
        uses: actions/checkout@v4

      - name: Install Nix
        uses: cachix/install-nix-action@v24
        with:
          extra_nix_config: |
            trusted-public-keys = public:O6JLD0yXzaJDPiQW1meVu32JIDViuaPtGDfjlOopU7o= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
            substituters = https://hercules.servers.lowrisc.org/nix-cache/public/ https://cache.nixos.org/

      - name: Setup Cache
        if: github.event_name != 'pull_request'
        run: |
          nix profile install github:zhaofengli/attic#attic
          attic login --set-default lowrisc https://hercules.servers.lowrisc.org/nix-cache/ ${{ secrets.NIX_CACHE_TOKEN }}

      - name: Build
        run: nix build ".#${{ matrix.attr }}"

      - name: Upload Cache
        if: github.event_name != 'pull_request'
        run: |
          attic push public result/