flake.nix

{
  description = "Reproducible Flutter and Android development environment for Fidget Toys";

  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

  outputs = { nixpkgs, ... }:
    let
      supportedSystems = [ "x86_64-linux" "aarch64-linux" ];
      forEachSystem = nixpkgs.lib.genAttrs supportedSystems;
    in
    {
      devShells = forEachSystem (system:
        let
          pkgs = import nixpkgs {
            inherit system;
            config = {
              allowUnfree = true;
              android_sdk.accept_license = true;
            };
          };
          androidComposition = pkgs.androidenv.composeAndroidPackages {
            platformVersions = [ "36" ];
            buildToolsVersions = [ "36.0.0" ];
            includeEmulator = false;
            includeSystemImages = false;
            includeNDK = true;
            ndkVersions = [ "28.2.13676358" ];
            # Flutter's sdkmanager check evaluates every current Android SDK
            # repository license family, not only the installed packages.
            # These are accepted declaratively under android_sdk.accept_license.
            extraLicenses = [
              "android-googletv-license"
              "android-googlexr-license"
              "android-sdk-arm-dbt-license"
              "android-sdk-preview-license"
              "google-gdk-license"
              "mips-android-sysimage-license"
            ];
          };
          androidSdk = androidComposition.androidsdk;
        in
        {
          default = pkgs.mkShell {
            packages = with pkgs; [
              flutter
              jdk17
              androidSdk
              avahi
              git
              just
              python3
              imagemagick
              curl
              unzip
              xz
              zip
            ];

            ANDROID_HOME = "${androidSdk}/libexec/android-sdk";
            ANDROID_SDK_ROOT = "${androidSdk}/libexec/android-sdk";
            ANDROID_NDK_ROOT = "${androidSdk}/libexec/android-sdk/ndk/28.2.13676358";
            JAVA_HOME = pkgs.jdk17.home;
            GRADLE_OPTS = "-Dorg.gradle.project.android.aapt2FromMavenOverride=${androidSdk}/libexec/android-sdk/build-tools/36.0.0/aapt2";
            FLUTTER_SUPPRESS_ANALYTICS = "true";

            shellHook = ''
              # mkShell inherits the host PATH. Remove only entries that expose
              # an adb different from this SDK's platform-tools binary so
              # Flutter doctor sees one coherent Android toolchain.
              canonical_adb="$ANDROID_SDK_ROOT/platform-tools/adb"
              if [ -x "$canonical_adb" ]; then
                canonical_adb_real="$(readlink -f "$canonical_adb")"
                filtered_path=""
                previous_ifs="$IFS"
                IFS=:
                for path_entry in $PATH; do
                  [ -n "$path_entry" ] || continue
                  candidate_adb="$path_entry/adb"
                  if [ -x "$candidate_adb" ] \
                    && [ "$(readlink -f "$candidate_adb")" != "$canonical_adb_real" ]; then
                    continue
                  fi
                  filtered_path="''${filtered_path:+$filtered_path:}$path_entry"
                done
                IFS="$previous_ifs"
                export PATH="$filtered_path"
              fi

              if [ -t 1 ]; then
                echo "Fidget Toys development shell"
                echo "Android SDK: $ANDROID_SDK_ROOT"
                echo "Run just env for a full environment check."
              fi
            '';
          };
        });
    };
}