CourseInfo.java

import java.util.ArrayList;
import java.util.Scanner;
import java.io.*;

public class CourseInfo {

   private String filename;
   private ArrayList<String[]> clist;

   public CourseInfo(String filename) {
      this.filename = filename;
      clist = new ArrayList<>();

      try {
         File file = new File(filename);
         Scanner scanner = new Scanner(file);

         while (scanner.hasNextLine()) {
            String line = scanner.nextLine().trim();
            if (line.equals(""))
               continue;

            String[] parts = line.split(",");

            for (int i = 0; i < parts.length; i++) {
               parts[i] = parts[i].trim();
            }

            clist.add(parts);
         }

         scanner.close();
      } catch (Exception e) {
      }
   }

   public void addCourse(String dept, String code, String title, int AKTS) {

      // test i iki kez çalıştırdığımda iki kez ekleme oldu
      for (int i = 0; i < clist.size(); i++) {
         String[] c = clist.get(i);
         if (c[0].equals(dept) && c[1].equals(code)) {
            return; // Ders zaten var ekleme yapmadan çık
         }
      }
      
      String[] newCourse = { dept, code, title, String.valueOf(AKTS) };
      clist.add(newCourse);

      try {
         PrintWriter writer = new PrintWriter(new FileWriter(filename));

         for (int i = 0; i < clist.size(); i++) {
            String[] c = clist.get(i);
            writer.println(c[0] + "," + c[1] + "," + c[2] + "," + c[3]);
         }

         writer.close();
      } catch (Exception e) {
      }
   }

   public ArrayList getCourses(String dept) {

      ArrayList<String> answer = new ArrayList<>();

      for (int i = 0; i < clist.size(); i++) {
         String[] c = clist.get(i);

         if (c[0].equals(dept)) {
            answer.add(c[0] + c[1]);
         }
      }

      return answer;
   }

   public void removeCourse(String dept, String code) {

      for (int i = 0; i < clist.size(); i++) {
         String[] c = clist.get(i);

         if (c[0].equals(dept) && c[1].equals(code)) {
            clist.remove(i);
            i--;
         }
      }

      try {
         PrintWriter writer = new PrintWriter(new FileWriter(filename));

         for (int i = 0; i < clist.size(); i++) {
            String[] c = clist.get(i);
            writer.println(c[0] + "," + c[1] + "," + c[2] + "," + c[3]);
         }

         writer.close();
      } catch (Exception e) {
      }
   }

   public void changeAKTS(String dept, String code, int AKTS) {

      for (int i = 0; i < clist.size(); i++) {
         String[] c = clist.get(i);

         if (c[0].equals(dept) && c[1].equals(code)) {
            c[3] = String.valueOf(AKTS);
         }
      }

      try {
         PrintWriter writer = new PrintWriter(new FileWriter(filename));

         for (int i = 0; i < clist.size(); i++) {
            String[] c = clist.get(i);
            writer.println(c[0] + "," + c[1] + "," + c[2] + "," + c[3]);
         }

         writer.close();
      } catch (Exception e) {
      }
   }

   public void changeCourseCode(String dept, String code, String newCode) {

      for (int i = 0; i < clist.size(); i++) {
         String[] c = clist.get(i);

         if (c[0].equals(dept) && c[1].equals(code)) {
            c[1] = newCode;
         }
      }

      try {
         PrintWriter writer = new PrintWriter(new FileWriter(filename));

         for (int i = 0; i < clist.size(); i++) {
            String[] c = clist.get(i);
            writer.println(c[0] + "," + c[1] + "," + c[2] + "," + c[3]);
         }

         writer.close();
      } catch (Exception e) {
      }
   }
}