VS Code API to get method name and their parameters from selected text

I am just trying to develop a new VS Code extension. Where I have the requirement to get method name, parameters, and return type if the user selects specific text.

public someMethodName(param_1:number, param_2:string):number{

.....some logic

}

Expected:

methodName: someMetodName

parameters = {
 param_1,
 param_2
}

returnType = number

Thanks, in advance.