package com.interview.design.pattern.j2ee;

/**
 * Created_By: stefanie
 * Date: 14-12-3
 * Time: 下午6:21
 *
 * MVC Pattern stands for Model-View-Controller Pattern. This pattern is used to separate application's concerns.
 *
 * Model - Model represents an object or JAVA POJO carrying data.
 *         It can also have logic to update controller if its data changes.
 * View -  View represents the visualization of the data that model contains.
 * Controller - Controller acts on both Model and view.
 *         It controls the data flow into model object and updates the view whenever data changes.
 *         It keeps View and Model separate.
 */
public class MVCPattern {
    static class Student {
        private String rollNo;
        private String name;
        public String getRollNo() {
            return rollNo;
        }
        public void setRollNo(String rollNo) {
            this.rollNo = rollNo;
        }
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
    }

    static class StudentView {
        public void printStudentDetails(String studentName, String studentRollNo){
            System.out.println("Student: ");
            System.out.println("Name: " + studentName);
            System.out.println("Roll No: " + studentRollNo);
        }
    }

    static class StudentController {
        private Student model;
        private StudentView view;

        public StudentController(Student model, StudentView view){
            this.model = model;
            this.view = view;
        }

        public void setStudentName(String name){
            model.setName(name);
        }

        public String getStudentName(){
            return model.getName();
        }

        public void setStudentRollNo(String rollNo){
            model.setRollNo(rollNo);
        }

        public String getStudentRollNo(){
            return model.getRollNo();
        }

        public void updateView(){
            view.printStudentDetails(model.getName(), model.getRollNo());
        }
    }

    public static void main(String[] args) {

        //fetch student record based on his roll no from the database
        Student model  = retriveStudentFromDatabase();

        //Create a view : to write student details on console
        StudentView view = new StudentView();

        StudentController controller = new StudentController(model, view);

        controller.updateView();

        //update model data
        controller.setStudentName("John");

        controller.updateView();
    }

    private static Student retriveStudentFromDatabase(){
        Student student = new Student();
        student.setName("Robert");
        student.setRollNo("10");
        return student;
    }
}