name: Build Pi NixOS Image
on:
  push:
    paths:
      - 'pi-imgs/**'
      - '.forgejo/workflows/build-pi-img.yml'

jobs:
  sync:
    runs-on: debian-latest-arm
    steps:
      - name: Checkout code
        uses: actions/checkout@v3.5.3
        with:
          ref: trunk

      - name: "Cache Nix store"
        uses: actions/cache@v3.0.8
        id: nix-cache
        with:
          path: /tmp/nixcache
          key: "pi-nix-cache-v1"

      - name: Install prerequisites
        run: apt update && apt install -y sudo zstd
      - name: Install Nix
        uses: https://github.com/cachix/install-nix-action@v22
        with:
          extra_nix_config: "experimental-features = nix-command flakes"
          nix_path: nixpkgs=channel:nixos-23.05
      - name: Remove access_tokens
        run: sed -i '/^access-tokens/d' /etc/nix/nix.conf

      - name: "Import Nix store cache"
        if: "steps.nix-cache.outputs.cache-hit == 'true'"
        run: "nix-store --import < /tmp/nixcache"

      - name: Build image
        run: nix build .#packages.aarch64-linux.raspberry-pi

      - uses: https://github.com/actions/upload-artifact@v3.1.2
        with:
          name: nixos-pi-23.05-${{ env.GITHUB_SHA }}.img
          path: result/sd-image/*.img

      - name: "Export Nix store cache"
        if: "steps.nix-cache.outputs.cache-hit != 'true'"
        run: "nix-store --export $(find /nix/store -maxdepth 1 -name '*-*') > /tmp/nixcache"