feat: add nix flake

.github/workflows/nix.yml

@@ -0,0 +1,57 @@
+name: Check nix packages
+on:
+    pull_request:
+      paths:
+        - "./*.nix"
+        - ".github/workflows/nix.yml"
+        - "assets/**"
+        - "customize/**"
+    push:
+        branches: [master]
+        paths:
+          - "./*.nix"
+          - ".github/workflows/nix.yml"
+          - "assets/**"
+          - "customize/**"
+jobs:
+    flake:
+        name: Check flake
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v4
+            - name: Check Nix flake inputs
+              uses: DeterminateSystems/flake-checker-action@v5
+              with:
+                send-statistics: false
+                fail-mode: true
+            - name: Install Nix
+              uses: DeterminateSystems/nix-installer-action@v9
+            - name: Check repository
+              run: nix flake check
+    matrix:
+        name: Generate build matrix
+        runs-on: ubuntu-latest
+        outputs:
+            themes: ${{ steps.generate-matrix.outputs.themes }}
+        steps:
+            - uses: actions/checkout@v4
+            - name: Generate matrix
+              id: generate-matrix
+              run: |
+                THEMES=$(ls assets/backgrounds/ | sed 's/\.png$//g' | jq --raw-input | jq --slurp -c)
+                echo "themes=$THEMES" >> $GITHUB_OUTPUT
+    build:
+        name: Check nix build for theme ${{ matrix.theme }}
+        runs-on: ubuntu-latest
+        needs:
+            - matrix
+        strategy:
+            matrix: 
+                theme: ${{ fromJSON(needs.matrix.outputs.themes) }}
+        steps:
+            - uses: actions/checkout@v4
+            - name: Install Nix
+              uses: DeterminateSystems/nix-installer-action@v9
+            - name: Build package
+              run: nix build .#${{ matrix.theme }}-grub-theme
+

.gitignore

@@ -0,0 +1,4 @@
+.envrc
+.direnv
+.vscode
+result

build/default.nix

@@ -0,0 +1,28 @@
+{ stdenvNoCC, lib, theme }:
+let
+  themes = builtins.map (theme: (builtins.head (lib.strings.splitString "." theme))) (builtins.attrNames (builtins.readDir ./../assets/backgrounds));
+in
+assert builtins.any (x: x == theme) themes;
+
+stdenvNoCC.mkDerivation {
+  name = "distro-grub-themes";
+  src = ./../.;
+
+  installPhase = ''
+    mkdir -p $out
+    cp ./assets/backgrounds/${theme}.png $out/background.png
+    cp ./assets/splash_image.jpg $out/splash_image.jpg
+    cp -r ./assets/icons $out
+    cp -r ./assets/fonts/. $out
+    cp -r ./assets/menu/. $out
+    cp -r ./assets/theme.txt $out
+  '';
+
+  meta = with lib; {
+    homepage = "https://github.com/AdisonCavani/distro-grub-themes";
+    description = "A pack of GRUB2 themes for each Linux distribution";
+    license = licenses.gpl3;
+    maintainers = with maintainers; [ zakuciael ];
+    platforms = platforms.linux;
+  };
+}

build/module.nix

@@ -0,0 +1,28 @@
+{ pks, lib, config, ... }:
+with lib;
+let
+  cfg = config.distro-grub-themes;
+  themes = builtins.map (theme: (builtins.head (lib.strings.splitString "." theme))) (builtins.attrNames (builtins.readDir ./../assets/backgrounds));
+in
+{
+  options.distro-grub-themes = {
+    enable = mkEnableOption "Enable Distro Grub Theme";
+    theme = mkOption {
+      type = types.enum themes;
+      default = "nixos";
+      example = "arch-linux";
+      description = ''
+        Selected theme name.
+        IMPORTANT! Theme name must be the same as in assert/backgrounds directory without the extension
+      '';
+    };
+  };
+
+  config = mkIf (cfg.enable)
+    {
+      boot.loader.grub = {
+        theme = pkgs.callPackage ./default.nix { theme = cfg.theme; };
+        splashImage = ./assets/splash_image.jpg;
+      };
+    };
+}

docs/Installation.mdx

@@ -84,6 +84,84 @@ sudo eopkg install grub-customizer
   To revert back to the orignal KDE Neon theme, open GRUB Customizer, and in the Appearance settings tab, change the theme dropdown back to breeze.
 </Callout>
 
+## Installation via Nix Flakes
+### Prerequisites
+- Nix 2.4 or later
+- Experimental features `nix-command` and `flakes` enabled.
+  - You can achive that by setting the following options and rebuilding your system.
+
+    ```nix:configuration.nix
+    nix = {
+      package = pkgs.nixFlakes;
+      extraOptions = ''
+        experimental-features = nix-command flakes
+      '';
+    };
+    ```
+
+### NixOS module
+To use this theme as a NixOS module, a bare-minimum configuration would be as follows:
+```nix:flake.nix
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    distro-grub-themes.url = "github:AdisonCavani/distro-grub-themes";
+  };
+  outputs = { self, nixpkgs, ... }@inputs: {
+    nixosConfigurations."default" = nixpkgs.lib.nixosSystem rec {
+      system = "x86_64-linux";
+      modules = [
+        ./configuration.nix
+        inputs.distro-grub-themes.nixosModules.${system}.default
+      ];
+    };
+  };
+}
+```
+
+```nix:configuration.nix 
+{ config, pkgs, lib, ... }: {
+  distro-grub-themes = {
+    enable = true;
+    theme = "<theme_name>";
+  };
+}
+```
+
+### Standalone setup
+To use this theme in a standalone setup, a bare-minimum configuration would be as follows:
+```nix:flake.nix
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    distro-grub-themes.url = "github:AdisonCavani/distro-grub-themes";
+  };
+  outputs = { self, nixpkgs, ... }@inputs: {
+    nixosConfigurations."default" = nixpkgs.lib.nixosSystem rec {
+      system = "x86_64-linux";
+
+      specialArgs = {
+        # Pass system and inputs to the configuration.nix file
+        inherit system inputs;
+      };
+
+      modules = [
+        ./configuration.nix
+      ];
+    };
+  };
+}
+```
+```nix:configuration.nix
+{ config, pkgs, lib, inputs, system, ... }: {
+
+  boot.loader.grub = rec {
+    theme = inputs.distro-grub-themes.packages.${system}.<theme_name>-grub-theme;
+    splashImage = "${theme}/splash_image.jpg";
+  };
+}
+```
+
 ## Manual Installation
 
 In order to clone the repository from GitHub, you have to install Git, via the `git` package.  

flake.nix

@@ -0,0 +1,40 @@
+{
+  description = "A pack of GRUB2 themes for each Linux distribution";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    { self, nixpkgs, flake-utils }:
+    let
+      systems = [ "aarch64-linux" "i686-linux" "x86_64-linux" ];
+    in
+    flake-utils.lib.eachSystem systems (
+      system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        themeNames = builtins.attrNames (builtins.readDir ./assets/backgrounds);
+        themePackages = builtins.listToAttrs (builtins.map
+          (theme:
+            let name = (builtins.head (pkgs.lib.strings.splitString "." theme)); in {
+              name = name + "-grub-theme";
+              value = pkgs.callPackage ./build/default.nix { theme = name; };
+            })
+          themeNames);
+      in
+      {
+        packages = {
+          default = pkgs.callPackage ./build/default.nix { theme = "nixos"; };
+        } // themePackages;
+
+        devShells.default = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [ nixd nixpkgs-fmt act jq ];
+        };
+
+        nixosModules.default = ./build/module.nix;
+      }
+    );
+}
+