import java.util.*;
import java.util.function.Consumer;

public class JsonRecursive {

    public void main() {
        JsObject tree = buildTree();

        // You are given an object tree that was generated by a JSON parser.
        // It contains nested JsValue objects. Each one is of one of these subtypes:
        //
        //   - JsConstant (just a leaf node with a value, accessible via getValue())
        //   - JsArray (contains elements, accessible via forEach(Consumer))
        //   - JsObject (contains fields, accessible via getFieldNames() and getField(name))
        //
        // Task 1:
        // For debugging purposes we want to quickly print the entire tree to the
        // console. Write a method that prints entire object tree in a human-readable
        // format. 
        //
        // Task 2:
        // By printing the parser result to the console, you just found out that
        // the field names are all in snake_case, while you definitely need them
        // in camelCase. Write a method that modifies the tree and converts all
        // field names. Use your previously written method to check the result.
    }

    // ------------------------------------------------------------------------
    // The following code may not be edited!
    // ------------------------------------------------------------------------

    private JsObject buildTree() {
        JsObject object = new JsObject();
        object.addField("some_silly_field", new JsConstant("Foo!"));
        object.addField("yet_another_pointless_field", new JsConstant("Bar!"));

        JsObject subSubObject = new JsObject();
        subSubObject.addField("field1", new JsConstant(42));
        subSubObject.addField("field_4_you", new JsConstant(23));

        JsObject subObject = new JsObject();
        subObject.addField("nothing", new JsConstant(false));
        subObject.addField("deeper_we_go", subSubObject);

        JsArray array = new JsArray();
        array.addElement(new JsConstant("This is not an object."));
        array.addElement(subObject);

        JsObject tree = new JsObject();
        tree.addField("schema_version", new JsConstant("1.1.0"));
        tree.addField("some_object", object);
        tree.addField("some_array", array);

        return tree;
    }

    abstract class JsValue {
        public boolean isObject() { return false; }
        public boolean isArray() { return false; }
        public boolean isConstant() { return false; }
    }

    class JsObject extends JsValue {
        private Map<String, JsValue> elements = new HashMap<>();

        @Override
        public boolean isObject() { return true; }

        public JsObject addField(String name, JsValue value) {
            this.elements.put(name, value);
            return this;
        }

        public JsObject deleteField(String name) {
            this.elements.remove(name);
            return this;
        }

        public Set<String> getFieldNames() {
            return new HashSet<String>(this.elements.keySet());
        }

        public JsValue getField(String name) {
            return this.elements.get(name);
        }

    }

    class JsArray extends JsValue {
        private List<JsValue> elements = new ArrayList<>();

        @Override
        public boolean isArray() { return true; }

        public JsArray addElement(JsValue element) {
            this.elements.add(element);
            return this;
        }

        public ListIterator<JsValue> getIterator() {
            return this.elements.listIterator();
        }

        public void forEach(Consumer<JsValue> action) {
            this.elements.forEach(action);
        }
    }

    class JsConstant extends JsValue {
        private Object value;

        public JsConstant(Object value) {
            this.value = value;
        }

        @Override
        public boolean isConstant() { return true; }

        public Object getValue() {
            return this.value;
        }
    }

}