feat: build android apk

.gitignore

@@ -25,3 +25,5 @@ dist-ssr
 
 .direnv
 .envrc
+kls_database.db
+keystore.properties

flake.nix

@@ -4,9 +4,13 @@
     old-nixpkgs.url =
       "github:NixOS/nixpkgs/0c19708cf035f50d28eb4b2b8e7a79d4dc52f6bb";
     flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
-  outputs = { nixpkgs, old-nixpkgs, flake-utils, ... }:
+  outputs = { nixpkgs, old-nixpkgs, flake-utils, rust-overlay, ... }:
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs {
@@ -15,14 +19,63 @@
             (final: prev: {
               inherit (old-nixpkgs.legacyPackages.${system}) webkitgtk_4_1;
             })
+            rust-overlay.overlays.default
           ];
+          config = {
+            allowUnfree = true;
+            android_sdk.accept_license = true;
+          };
         };
+
+        rust-toolchain = pkgs.rust-bin.stable.latest.default.override {
+          targets = [
+            "x86_64-unknown-linux-gnu"
+            "x86_64-linux-android"
+            "aarch64-linux-android"
+            "armv7-linux-androideabi"
+            "i686-linux-android"
+          ];
+        };
+
+        androidComposition = pkgs.androidenv.composeAndroidPackages {
+          cmdLineToolsVersion = "13.0";
+          toolsVersion = "26.1.1";
+          platformToolsVersion = "35.0.1";
+          buildToolsVersions = [ "30.0.3" "34.0.0" ];
+          includeEmulator = false;
+          platformVersions = [ "28" "29" "30" "33" "34" ];
+          includeSources = false;
+          includeSystemImages = false;
+          systemImageTypes = [ "google_apis_playstore" ];
+          abiVersions = [ "armeabi-v7a" "arm64-v8a" ];
+          cmakeVersions = [ "3.10.2" ];
+          includeNDK = true;
+          ndkVersions = [ "26.3.11579264" ];
+          useGoogleAPIs = false;
+          useGoogleTVAddOns = false;
+          includeExtras = [ "extras;google;gcm" ];
+        };
+
       in rec {
         packages.default = pkgs.callPackage ./package.nix { };
         devShells.default = pkgs.mkShell {
           inherit (packages.default) buildInputs;
           nativeBuildInputs = packages.default.nativeBuildInputs
             ++ (with pkgs; [ rustc gcc rustfmt clippy ]);
         };
+
+        devShells.android = pkgs.mkShell rec {
+          inherit (packages.default) buildInputs;
+          nativeBuildInputs = packages.default.nativeBuildInputs
+            ++ [ rust-toolchain androidComposition.androidsdk ]
+            ++ (with pkgs; [ jdk17 gradle ]);
+
+          ANDROID_HOME = "${androidComposition.androidsdk}/libexec/android-sdk";
+          NDK_HOME = "${ANDROID_HOME}/ndk-bundle";
+          GRADLE_OPTS =
+            "-Dorg.gradle.project.android.aapt2FromMavenOverride=${androidComposition.androidsdk}/libexec/android-sdk/build-tools/34.0.0/aapt2";
+          XDG_DATA_DIRS =
+            "${pkgs.gsettings-desktop-schemas}/share/gsettings-schemas/${pkgs.gsettings-desktop-schemas.name}:${pkgs.gtk3}/share/gsettings-schemas/${pkgs.gtk3.name}";
+        };
       });
 }