flake.nix

{
  description = "A flake with pre-commit hooks";

  inputs = {
    flake-parts.url = "github:hercules-ci/flake-parts";
    flake-parts.inputs.nixpkgs-lib.follows = "nixpkgs";
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable-small";
    pre-commit-hooks-nix.url = "github:cachix/pre-commit-hooks.nix";
    pre-commit-hooks-nix.inputs.nixpkgs.follows = "nixpkgs";

    antora-ui.url = "git+https://gitlab.com/hercules-ci/antora-hercules-ci-theme";
    antora-ui.inputs.nixpkgs.follows = "nixpkgs";
    antora-ui.inputs.flake-parts.follows = "flake-parts";
  };

  outputs = inputs@{ self, flake-parts, hercules-ci-effects, ... }:
    flake-parts.lib.mkFlake
      { inherit inputs; }
      ({ lib, withSystem, ... }: {
        imports = [
          inputs.hercules-ci-effects.flakeModule
          inputs.pre-commit-hooks-nix.flakeModule
        ];
        systems = [ "x86_64-linux" ];
        hercules-ci.flake-update = {
          enable = true;
          when = {
            dayOfMonth = 5;
          };
        };
        perSystem = { config, self', inputs', pkgs, ... }:
          let
            linkGeneratedFiles = ''
              set-link ${inputs'.antora-ui.packages.antora-ui} ui-bundle
            '';
          in
          {
            packages.antora = pkgs.callPackage ./antora/package.nix { };
            packages.antora-ui = inputs'.antora-ui.packages.antora-ui;
            pre-commit.settings.hooks.nixpkgs-fmt.enable = true;
            pre-commit.settings.excludes = [
              # The snippets didn't improve. May try again later.
              "docs/modules/ROOT/partials/snippets"
            ];
            devShells.default = pkgs.mkShell {
              nativeBuildInputs = [
                config.packages.antora
                pkgs.inotify-tools
                pkgs.netlify-cli
                pkgs.nixpkgs-fmt
                pkgs.yarn
              ];
              NODE_PATH = config.packages.antora.node_modules;
              shellHook = ''
                ${config.pre-commit.shellHook}

                # Set up generated symlinks (GC roots pattern from hercules-ci-frontend)
                set-link() {
                  echo "Adding root for $2"
                  nix-store -r --add-root "$2" "$1" >/dev/null
                }
                ${linkGeneratedFiles}

                echo
                echo 1>&2 "antora $(antora --version)"
                cat 1>&2 <<EOF

                Welcome to the docs.hercules-ci.com shell

                Commands:
                  live-rebuild        Performs a local build whenever watched files change.
                  open-browser        Opens the homepage in a browser

                EOF
                last_status() {
                  local r=$?
                  if [[ $r = 0 ]]; then
                    echo ok
                  elif [[ $r = 1 ]]; then
                    echo FAILED
                  else
                    echo "FAILED ($r)"
                  fi
                }
                live-rebuild() {
                  (
                    echo 1>&2 "Press ENTER to force a rebuild."
                    inotifywait -mr . ../hercules-ci-effects ../arion ../hercules-ci-agent -e MODIFY \
                      | grep --line-buffered -E 'adoc|hbs|(lib/.*\.js)' &
                    cleanup() {
                      kill %%
                    }
                    trap cleanup EXIT
                    echo first build for good measure
                    cat
                    ) | while read ln; do
                        echo 1>&2 "antora starting..."
                        antora antora-playbook-local.yml --stacktrace
                        echo 1>&2 "antora finished ($(last_status)) at $(date +%T)";
                      done
                }

                open-browser() {
                  xdg-open public/index.html
                }
              '';

              LANG = "en_US.utf8";
            };
          };
        herculesCI = { config, ... }:
          let
            inherit (config.repo) branch;
            isProd = branch == "master";
            deploy = withSystem "x86_64-linux" ({ config, pkgs, hci-effects, ... }:
              hci-effects.netlifyDeploy {
                siteId = "48f50b78-b03a-4f2b-bc57-8e043b0f569f";
                secretName = "default-netlify";
                productionDeployment = isProd;
                content = "./public";
                src = ./.;
                nativeBuildInputs = [
                  config.packages.antora
                  pkgs.tree
                  pkgs.git
                  pkgs.nix
                ];
                # TODO package the extension properly
                NODE_PATH = config.packages.antora.node_modules;
                preEffect = ''
                  mkdir -p public
                  mkdir -p ~/.config/nix
                  echo >>~/.config/nix/nix.conf experimental-features = flakes nix-command
                  git config --global user.email "no-reply@hercules-ci.com"
                  git config --global user.name CI
                  git config --global init.defaultBranch master
                  git init .
                  git remote add origin https://github.com/hercules-ci/docs.hercules-ci.com
                  git add -N .
                  git commit -m init .
                  git checkout -B ${lib.escapeShellArg branch}

                  # Set up UI bundle
                  ln -sfn ${config.packages.antora-ui} ui-bundle

                  checklog() {
                    tee $TMPDIR/err
                    ! grep -E 'ERROR'
                  }
                  export CI=true;
                  export FORCE_SHOW_EDIT_PAGE_LINK=true;
                  antora --fetch ./antora-playbook.yml --stacktrace 2>&1 | checklog;
                  rm -rf public
                  antora --url https://docs.hercules-ci.com --html-url-extension-style=indexify --redirect-facility=netlify ./antora-playbook.yml 2>&1 | checklog;
                  cat <./_redirects >>./public/_redirects
                '' + lib.optionalString (!isProd) ''
                  { echo 'User-agent: *'
                    echo 'Disallow: /'
                  } >public/robots.txt
                '';
                extraDeployArgs = [
                  # "--debug"
                ] ++ lib.optionals (!isProd) [
                  "--alias"
                  branch
                ];
              }
            );
          in
          {
            onPush.default = {
              outputs = {
                effects.netlifyDeploy = deploy;
              };
            };
            onSchedule.scheduled-deploy = {
              outputs.effects.netlifyDeploy = deploy;
              when.hour = [ 0 6 12 18 ];
            };
          };
      });
}