flake.nix for netpad-player

flake.nix

{
  description = "Netpad Player - A Nix flake for the Netpad Player application.";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/release-24.11"; # It's generally recommended to use a stable channel, but for accessing 'electron', unstable might be needed.  Adjust as necessary.
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          config = {
            allowUnfree = true;
          };
        };
        pkgname = "netpad-player";
        pkgver = "1.6.4";
        src = pkgs.fetchurl {
          url = "https://www.netpad.net.cn/download/NetpadPlayer-${pkgver}.exe";
          sha256 = "7b53d020786843c71e13b260fb7d5d60c483b6eed0271fb9b1a5a1aeda1f2092";
        };

        #The prepare step. Extracts the asar archive and removes unnecessary files.
        extractedApp = pkgs.stdenv.mkDerivation {
          name = "${pkgname}-extracted";
          version = pkgver;
          src = src;
          nativeBuildInputs = [ pkgs.asar pkgs.p7zip ];
          unpackPhase = ''
             mkdir -vp extracted
             7z x $src -oextracted # Use 7z to extract from the exe.
             7z x extracted/\$PLUGINSDIR/app-32.7z
             asar extract resources/app.asar ./app
          '';

           installPhase = ''
            mkdir -p $out
            cp -r ./app $out/
           # find $srcdir -name app.asar -exec asar e {} ./app \;   -> Above asar extract command.
            find $out -type f -path "*/darwin/*" -delete
            find $out -name "*.rar" -delete
            find $out -path "*/bin/*.js" -delete
            find $out -name "*.js.map" -delete
          '';
        };

        # The desktop file content, embedded directly.  This is cleaner than a separate file.
        desktopFileContent = ''
          [Desktop Entry]
          Version=1.0
          Type=Application
          Name=netpad-player
          Name[zh_CN]=网络画板离线播放器
          Comment=网络画板，用核心技术赋能智慧数学教育
          Exec=netpad-player
          Icon=netpad-player
          Terminal=false
          StartupNotify=false
          Categories=Application;
        '';


      in
      {
        packages = {
          default = pkgs.stdenv.mkDerivation {
            name = pkgname;
            version = pkgver;

            src = extractedApp;  # Use the extracted app as the source.


            nativeBuildInputs = [ pkgs.makeWrapper ]; # For creating the wrapper script.
            buildInputs = [ pkgs.electron-bin ]; # Provide electron for runtime.

              installPhase = ''
              mkdir -p $out/opt/${pkgname}
              cp -r $src/* $out/opt/${pkgname}/

              # Create a wrapper script to launch the application using electron.
              makeWrapper ${pkgs.electron-bin}/bin/electron $out/bin/${pkgname} \
                --add-flags "$out/opt/${pkgname}/app"

                # Create the desktop file.
              mkdir -p $out/share/applications
              echo "${desktopFileContent}" > $out/share/applications/${pkgname}.desktop

              find $out -name "icon.png" -print -exec install -Dm644 {} $out/share/pixmaps/${pkgname}.png \;

            '';


             meta = with pkgs.lib; {
              description = "网络画板，用核心技术赋能智慧数学教育";
              homepage = "https://www.netpad.net.cn/";
              license = licenses.unfree; #  'custom' is not a valid SPDX identifier, so use 'unfree'.
              platforms = platforms.all; #  'any' arch, so it should work on all platforms that support Electron.
              maintainers = [ "Asuka Minato <i at asukaminato dot eu dot org>" ]; # Maintainer info.
            };

          };
          # netpad-player = self.packages.${system}.default;

        };
      });
}