package dev;


import dev.model.Student;
import dev.service.StudentManager;
import dev.thread.StudentLoader;
import dev.utils.FileManager;


import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;


public class Main {


    public static void main(String[] args) throws Exception {


        Scanner scanner = new Scanner(System.in);


        StudentManager manager =
                new StudentManager();



        while (true) {


            System.out.println("""
                    1.Load students
                    2.Search student
                    3.Remove student
                    4.Print students
                    5.Exit
                    """);



            int choice = scanner.nextInt();



            switch (choice) {



                case 1 -> {


                    List<String> data =
                            FileManager.loadStudents("students.txt");



                    int size = data.size();


                    int part = (int)Math.ceil(size / 3.0);



                    List<String> part1 =
                            data.subList(
                                    0,
                                    Math.min(part,size)
                            );


                    List<String> part2 =
                            data.subList(
                                    Math.min(part,size),
                                    Math.min(part*2,size)
                            );


                    List<String> part3 =
                            data.subList(
                                    Math.min(part*2,size),
                                    size
                            );



                    StudentLoader t1 =
                            new StudentLoader(part1);


                    StudentLoader t2 =
                            new StudentLoader(part2);


                    StudentLoader t3 =
                            new StudentLoader(part3);



                    t1.start();

                    t2.start();

                    t3.start();



                    t1.join();

                    t2.join();

                    t3.join();




                    ArrayList<Student> finalList =
                            new ArrayList<>();


                    finalList.addAll(t1.getStudents());

                    finalList.addAll(t2.getStudents());

                    finalList.addAll(t3.getStudents());



                    manager.addStudents(finalList);



                    System.out.println(
                            "Students loaded: "
                                    + finalList.size()
                    );


                }



                case 2 -> {


                    System.out.print("ID: ");


                    int id = scanner.nextInt();



                    Student student =
                            manager.searchStudent(id);



                    if(student != null){

                        System.out.println("Found:");

                        System.out.println(student);

                    }

                    else{

                        System.out.println("Student not found.");

                    }


                }



                case 3 -> {


                    System.out.print("ID: ");


                    int id = scanner.nextInt();


                    System.out.println(
                            manager.removeStudent(id)
                    );


                }



                case 4 -> {


                    manager.printStudents();


                }



                case 5 -> {


                    return;


                }


            }

        }

    }

}