{
  description = "APKs demonstrating class shadowing.";
  inputs = {
    nixpkgs.url = github:nixos/nixpkgs/nixos-unstable;
    flake-utils.url = github:numtide/flake-utils;
  };

  outputs = { self, nixpkgs, flake-utils }: 
    flake-utils.lib.eachDefaultSystem (system:
    let
      pkgs = import nixpkgs {
        system = system;
        config = {
          android_sdk.accept_license = true;
          allowUnfree = true;
        };
      };
      #pkgs = nixpkgs.legacyPackages.${system};
      jdk = pkgs.javaPackages.compiler.openjdk17;
      android-env = pkgs.androidenv.composeAndroidPackages {
        buildToolsVersions = [ "34.0.0" ];
        platformVersions = [ "34" ];
      };
      platforms = "${builtins.head android-env.platforms}/libexec/android-sdk/platforms/android-34";
      build-tools = "${builtins.head android-env.build-tools}/libexec/android-sdk/build-tools/34.0.0";
#      build-tools = pkgs.runCommandNoCC "build-tools-v34_0_0-unzip" {} ''
#        ${pkgs.unzip}/bin/unzip ${pkgs.androidenv.androidPkgs.all.packages.build-tools.v34_0_0} -d tmp
#        mkdir $out
#        mv tmp/android-14/* $out/
#        patchShebangs $out/d8
#      '';
#      platforms = pkgs.runCommandNoCC "platforms-v34_0_0-unzip" {} ''
#        ${pkgs.unzip}/bin/unzip ${pkgs.androidenv.androidPkgs.all.packages.platforms.v34} -d tmp
#        mkdir $out
#        mv tmp/android-34/* $out/
#      '';
      
    in rec {

      packages = {
        default = pkgs.stdenvNoCC.mkDerivation rec {
          name = "com-example-shadowing.apk";
          src = self;
          buildInputs = [ jdk android-env.androidsdk pkgs.which ];
          phases = ["unpackPhase" "buildPhase" "installPhase"];
          buildPhase = ''
            mkdir build

            ${jdk}/bin/javac -classpath ${platforms}/android.jar java/classes/com/example/shadowing/MainActivity.java -d build/
            file build/com/example/shadowing/MainActivity.class >> build/tools.txt
            echo $(which d8) --classpath ${platforms}/android.jar build/com/example/shadowing/MainActivity.class --output build/ >> build/tools.txt
            d8 --classpath ${platforms}/android.jar build/com/example/shadowing/MainActivity.class --output build/
            mkdir -p build/apk_files/

            cp build/classes.dex build/apk_files/
            # link classes.dex not working?
            # ${build-tools}/aapt2 link -v ---manifest AndroidManifest.xml -I ${platforms}/android.jar -o build/app.apk build/apk_files/
            ${build-tools}/aapt package -v -f -M AndroidManifest.xml -I ${platforms}/android.jar -F build/app.apk build/apk_files/
            ${build-tools}/zipalign -f 4 build/app.apk build/app.aligned.apk

            keytool -genkeypair -validity 1000 -dname "CN=SomeKey,O=SomeOne,C=FR" -keystore build/ToyKey.keystore -storepass 'P@ssw0rd!' -keypass 'P@ssw0rd!' -alias SignKey -keyalg RSA -v
            ${build-tools}/apksigner sign -ks build/ToyKey.keystore --v2-signing-enabled true --in build/app.aligned.apk --out build/app.signed.apk --ks-pass 'pass:P@ssw0rd!'
          '';
          installPhase = ''
            mkdir $out
            cp build/app.signed.apk $out/
            cp build/app.signed.apk.idsig $out/
          '';
        };
      };

      devShells.default = pkgs.mkShellNoCC {
          packages = [ jdk android-env.androidsdk ];
          #shellHook = ''
          #'';
      };
    })
  ;
}