How to add a new method and method call using ast-grep in Java code

I'm working with ast-grep and trying to modify Java code by adding a new method at the end of the class (not necessarily at end, it can be anywhere in class )and inserting a method call. Despite several attempts, I haven't been able to figure out the correct approach.

Here's what I'm trying to achieve:

1. Add required imports in the import section of the class.

import com.company.package.agent.OverBuilder;
import com.company.package.agent.config.OverApplication;
import com.company.package.agent.config.OverGroup;
import com.company.package.agent.OverNoOpImpl;

2. In the method containing SpecificClassName.initialize(arg1, arg2, arg3); line, After this line, add a new line to call method initOverAgent();

SpecificClassName.initialize(arg1, arg2, arg3);
initOverAgent();

3. Declare initOverAgent method in the class.

Notes:

1. The class can be a simple class, or it can be extending some class or implementing an interface, e.g.:

   @Log4j2
   public class StoneModule implements Module {
   

   or

   @Log4j2
   public final class FitnessReportTool {
   

   or

   public class ConfigModule extends AbstractModule {
   

2. The class can have some, none, or many annotations like:

   @Module
   @Log4j2
   

3. If SpecificClassName.initialize(arg1, arg2, arg3); line is within a static method, the declaration of initOverAgent should be static; otherwise, it should be non-static.

Here's an example of the original class and the desired output:

Original class:

package com.company.package;

import com.google.inject.Injector;
import org.slf4j.Logger;

public class Remapter {
    public static void main(String[] args) throws Throwable {
        ...
    }
    private static synchronized void stopServer(BobcatServer server) {
        ...
    }
    private static void initSpecificClassName(String[] args3) throws InterruptedException 
    {
        ...someCode
        SpecificClassName.initialize(arg1, arg2, arg3);
        ...someCode
    }
}

Desired output:

package com.company.package;

import com.google.inject.Injector;
import org.slf4j.Logger;
import com.company.package.agent.OverBuilder;
import com.company.package.agent.config.OverApplication;
import com.company.package.agent.config.OverGroup;
import com.company.package.agent.OverNoOpImpl;

public class Remapter {
    public static void main(String[] args) throws Throwable {
        ...
    }
    private static synchronized void stopServer(BobcatServer server) {
        ...
    }
    private static void initSpecificClassName(String[] args3) throws InterruptedException 
    {
        ...someCode
        SpecificClassName.initialize(arg1, arg2, arg3);
        initOverAgent();
        ...someCode
    }  
    public static void initOverAgent() {
        if (!staticCondition) {
            new OverNoOpImpl().start();
        }
        new OverBuilder()
            .withOverGroup(new OverGroup().withName(NAME)
            .withOverApplication(new OverApplication().withApplicationName(APP_NAME)
            .build().start();
    }
}

I've tried using some YAML configuration, but I'm not able to satisfy all my required conditions.

id: declareOverAgent
language: java
rule:
  kind: class_declaration
  pattern: |
    @$A
    public class $CLASS {
      $$$CLASS_BODY
    }
fix: |-
  @$A
  public class $CLASS {
    $$$CLASS_BODY
    public static void initOverAgent() {
        if (!staticCondition) {
            new OverNoOpImpl().start();
        }
        new OverBuilder()
            .withOverGroup(new OverGroup().withName(NAME)
            .withOverApplication(new OverApplication().withApplicationName(APP_NAME)
            .build().start();
    }
  }
---
id: initializeOverAgent
language: java
rule:
  kind: expression_statement
  pattern: SpecificClassName.initialize(arg1, arg2, arg3);
fix: |-
  SpecificClassName.initialize(arg1, arg2, arg3);
  initializeCloudCoverJavaAgent();

I've been looking through the ast-grep documentation but haven't found a clear way to achieve this. Could someone please help me with how to add new method in the class and the method call ?

Any help or guidance would be greatly appreciated!