import java.io.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map.Entry;

import java.util.Scanner;

public class CsvDatabase implements java.io.Serializable {

    static public class Student implements java.io.Serializable {
        public int id = 0;
        public String firstName;
        public String lastName;
        public String age;
        public String homeTown;

        public Student() {

        }

        public Student(int id, String firstName, String lastName, String age, String homeTown) {
            this.id = id;
            this.firstName = firstName;
            this.lastName = lastName;
            this.age = age;
            this.homeTown = homeTown;
        }

        public String ToString() {
            return new String(firstName + " " + lastName + " (age: " + age + ", town: " + homeTown + ")");
        }
    }

    static public class Subject implements java.io.Serializable {

        public String subject;
        public List<Double> grades = new ArrayList<Double>();

        public Subject() {

        }

        public Subject(String subject, String grade) {
            this.subject = subject;
            this.grades.add(Double.parseDouble(grade));
        }

    }

    public static void main(String[] args) {
        String input;
        Scanner scan = new Scanner(System.in);

        HashMap<Integer, Student> students = new HashMap<Integer, Student>();
        HashMap<String, ArrayList<Subject>> grades = new HashMap<String, ArrayList<Subject>>();
        ArrayList<Subject> list = new ArrayList<Subject>();

        try (ObjectInputStream ios = new ObjectInputStream(new FileInputStream(new File("res/Students.save")));
                ObjectInputStream ios2 = new ObjectInputStream(new FileInputStream(new File("res/Grades.save")))) {
            students = (HashMap<Integer, Student>) ios.readObject();
            grades = (HashMap<String, ArrayList<Subject>>) ios2.readObject();
            System.out.println("Successfully loaded data from files.");
        } catch (IOException | ClassNotFoundException e) {
            System.out.println("File error");
        }

        while (true) {
            input = scan.nextLine();
            if (input.equals(new String("end"))) {
                break;
            }
            String[] command = input.split(" ");
            switch (command[0]) {
            case "Insert-student":
                students.put(students.size(),
                        new Student(students.size(), command[1], command[2], command[3], command[4]));
                System.out.println("Student added");
                break;
            case "Insert-grade-by-id":
                list.add(new Subject(command[2], command[3]));
                grades.put(command[1], list);
                System.out.println("Grade added");
                break;
            case "Delete-by-id":
                if (students.containsKey(Integer.parseInt(command[1]))) {
                    students.remove(Integer.parseInt(command[1]));
                    System.out.println("Student removed");
                    if (grades.containsKey(command[1])) {
                        grades.remove(command[1]);
                        System.out.println("And it's existing grades removed");
                    }
                } else {
                    System.out.println("Student does not exist");
                }
            case "Search-by-id":
                if (students.containsKey(Integer.parseInt(command[1]))) {
                    String studInfo = students.get(Integer.parseInt(command[1])).ToString();
                    System.out.println(studInfo);
                    if (grades.containsKey(command[1])) {
                        List<Subject> gradeInfo = grades.get(command[1]);
                        for (Subject s : gradeInfo) {
                            System.out.printf(" # %s: ", s.subject);
                            for (double d : s.grades) {
                                System.out.print(d);
                            }
                        }

                    }
                } else {
                    System.out.println("Students does not exist");
                }
            case "Search-by-full-name":
                for (Entry<Integer, Student> entry : students.entrySet()) {
                    Integer key = entry.getKey();
                    Student value = entry.getValue();
                    if (value.firstName.equals(command[1]) && value.lastName.equals(command[2])) {
                        String studInfo = students.get(key).ToString();
                        if (grades.containsKey(key)) {
                            List<Subject> gradeInfo = grades.get(key);
                            for (Subject s : gradeInfo) {
                                System.out.printf(" # %s: ", s.subject);
                                for (double d : s.grades) {
                                    System.out.print(d);
                                }
                            }
                        }
                    }
                }
            }
        }
        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(new File("res/Students.save")));
                ObjectOutputStream oos2 = new ObjectOutputStream(new FileOutputStream(new File("res/Grades.save")))) {
            oos.writeObject(students);
            oos2.writeObject(grades);
            System.out.println("Successfully saved data to files.");
        } catch (IOException e) {
            System.out.println("File error");
        }
    }

}