Support devenv up (#324)

* refactor: update devenv file for better building
* fix: remove redundant files

devenv.nix

@@ -1,19 +1,51 @@
 { pkgs, lib, config, inputs, ... }:
 
 {
-	languages.java.jdk.package = pkgs.jdk21;
-	languages.scala.package = pkgs.scala;
-	languages.scala.enable = true;
-	languages.scala.sbt.package = pkgs.sbt;
-	languages.scala.sbt.enable = true;
+    languages.scala.enable = true;
+    languages.scala.sbt.enable = true;
 
-  packages = [ pkgs.curl pkgs.git ];
+    packages = [ pkgs.curl pkgs.git pkgs.jdk21 pkgs.scala pkgs.sbt ];
 
-	processes = {
-		sbt-package.exec = "sbt packageAll; exit";
-	};
+    env = {
+        VSYS_JAR_FILE = "./target/vsys-all-0.4.2.jar";
+        VSYS_CONF_FILE = "./vsys-mainnet.conf";
+    };
 
-  enterShell = ''
-	echo "SBT environment"
-  '';
+    processes = {
+        build.exec = ''
+        if [ ! -e "$VSYS_JAR_FILE" ]; then
+            sbt packageAll
+            else echo "Jar file already exists, skipping build...";
+        fi'';
+
+        run.exec = ''
+        echo "Waiting for jar file to be built...";
+        while [ ! -e "$VSYS_JAR_FILE" ]; do
+            sleep 1;
+        done;
+        sleep 5;
+
+        echo "Starting VSYS node...";
+        for attempt in seq 1 5; do
+            java -jar $VSYS_JAR_FILE $VSYS_CONF_FILE;
+            if [ $? -eq 0 ]; then
+                break;
+            fi;
+            
+            if [ $attempt -eq 1 ]; then
+                echo "Failed to start VSYS node, retrying...";
+            fi;
+
+            if [ $attempt -eq 5 ]; then
+                echo "Failed to start VSYS node, exiting...";
+                exit 1;
+            fi;
+
+            sleep 5;
+        done'';
+    };
+
+    enterShell = ''
+    echo "SBT environment"
+    '';
 }