flake.nix: add wallet-ledger-export package

Author: msgilligan

flake.lock

@@ -7,6 +7,11 @@
 
   outputs = { self, nixpkgs, flake-utils }:
     let
+      systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin" ];
+      forEachSystem = f: builtins.listToAttrs (map (system: {
+        name = system;
+        value = f system;
+      }) systems);
     in {
       devShells = forEachSystem (system:
         let
@@ -20,6 +25,54 @@
                 echo "Welcome to WalletLedgerExport"
               '';
             };
-         });
+         }
+      );
+     packages = forEachSystem (system: {
+         wallet-ledger-export =
+           let
+             pkgs = import nixpkgs {
+               inherit system;
+             };
+             mainProgram = "wallet-ledger-export";
+             gradle = pkgs.gradle_8;
+             jre = pkgs.jdk21_headless;  # JRE to run the example with
+             self2 = pkgs.stdenv.mkDerivation (_finalAttrs: {
+               pname = "wallet-ledger-export";
+               version = "0.0.2-SNAPSHOT";
+               meta = {
+                 inherit mainProgram;
+               };
+
+               src = self;  # project root is source
+
+               nativeBuildInputs = [gradle pkgs.makeWrapper];
+
+               mitmCache = gradle.fetchDeps {
+                 pkg = self2;
+                 # update or regenerate this by running:
+                 #  $(nix build .#wallet-ledger-export.mitmCache.updateScript --print-out-paths)
+                 data = ./nix-deps.json;
+               };
+
+               gradleBuildTask = "ledger-export-tool:installDist";
+
+               gradleFlags = [ "--info --stacktrace" ];
+
+               # will run the gradleCheckTask (defaults to "test")
+               doCheck = false;
+
+               installPhase = ''
+                  mkdir -p $out/{bin,share/${mainProgram}/lib}
+                  cp ledger-export-tool/build/install/LedgerExport/lib/*.jar $out/share/${mainProgram}/lib
+                  # Compute CLASSPATH: all .jar files in $out/share/${mainProgram}/lib
+                  export MYPATH=$(find $out/share/${mainProgram}/lib -name "*.jar" -printf ':%p' | sed 's|^:||')  # Colon-separated, no leading :
+
+                  makeWrapper ${jre}/bin/java $out/bin/${mainProgram} \
+                        --add-flags "-cp $MYPATH org.consensusj.ledgerexport.tool.WalletAccountingExport" \
+                '';
+               });
+           in
+             self2;
+       });
     };
 }