feat(search): add occurrence counting menu and student settings

- add occurrence counting menu using StudentOccurrenceIndexFinder
- add student settings window for configuring search target
- display occurrence count and matching indices
- update current collection menu to delegate occurrence counting

app/src/main/java/ru/project/ui/collection/CurrentCollectionMenu.java

@@ -4,6 +4,7 @@ import com.googlecode.lanterna.gui2.ActionListBox;
 import com.googlecode.lanterna.gui2.WindowBasedTextGUI;
 import ru.project.model.AppState;
 import ru.project.ui.base.BaseModalWindow;
+import ru.project.ui.collection.counting.CountOccurrencesMenu;
 import ru.project.ui.collection.search.SearchCollectionMenu;
 import ru.project.ui.collection.sorting.SortCollectionMenu;
 import ru.project.ui.common.CollectionDisplayWindow;
@@ -15,8 +16,7 @@ public class CurrentCollectionMenu extends BaseModalWindow {
 
   private final SortCollectionMenu sortCollectionMenu;
   private final SearchCollectionMenu searchCollectionMenu;
-
+  private final CountOccurrencesMenu countOccurrencesMenu;
-  // private final CountOccurrencesMenu countOccurrencesMenu;
 
   public CurrentCollectionMenu(WindowBasedTextGUI gui, AppState state) {
 
@@ -28,7 +28,7 @@ public class CurrentCollectionMenu extends BaseModalWindow {
 
     this.searchCollectionMenu = new SearchCollectionMenu(gui, state);
 
-    // this.countCollectionMenu = new CountOccurrencesMenu(gui, state);
+    this.countOccurrencesMenu = new CountOccurrencesMenu(gui, state);
 
     ActionListBox menu = new ActionListBox();
     menu.addItem("Показать коллекцию...", this::showCurrentCollection);
@@ -39,7 +39,7 @@ public class CurrentCollectionMenu extends BaseModalWindow {
 
     menu.addItem("Меню поиска элемента в коллекции", searchCollectionMenu::showModal);
 
-    menu.addItem("Меню подсчёта количества вхождений элемента", this::countOccurrences);
+    menu.addItem("Меню подсчёта количества вхождений элемента", countOccurrencesMenu::showModal);
 
     menu.addItem("Выйти", this::close);
 
@@ -57,10 +57,4 @@ public class CurrentCollectionMenu extends BaseModalWindow {
 
     window.showModal();
   }
-
-  private void countOccurrences() {
-    // CountOccurrencesMenu countOccurrencesMenu = new CountOccurrencesMenu(gui, state);
-    //
-    // countOccurrencesMenu.showModal();
-  }
 }

app/src/main/java/ru/project/ui/collection/counting/CountOccurrencesMenu.java

@@ -0,0 +1,109 @@
+package ru.project.ui.collection.counting;
+
+import com.googlecode.lanterna.gui2.Button;
+import com.googlecode.lanterna.gui2.Label;
+import com.googlecode.lanterna.gui2.LinearLayout;
+import com.googlecode.lanterna.gui2.Panel;
+import com.googlecode.lanterna.gui2.WindowBasedTextGUI;
+import ru.project.collection.MyList;
+import ru.project.finder.StudentOccurrenceIndexFinder;
+import ru.project.model.AppState;
+import ru.project.student.Student;
+import ru.project.ui.base.BaseModalWindow;
+import ru.project.ui.common.MessageWindow;
+
+public class CountOccurrencesMenu extends BaseModalWindow {
+
+  private final AppState state;
+
+  private final OccurrenceStudentSettingsWindow occurrenceStudentSettingsWindow;
+
+  private Student selectedStudent;
+  private int occurrences;
+
+  private final Label studentLabel;
+  private final Label occurrencesLabel;
+
+  public CountOccurrencesMenu(WindowBasedTextGUI gui, AppState state) {
+
+    super("Меню подсчёта количества вхождений элемента", gui);
+
+    this.state = state;
+    this.selectedStudent = null;
+    this.occurrences = 0;
+
+    this.studentLabel = new Label("Элемент для поиска: не задан");
+
+    this.occurrencesLabel = new Label("Количество вхождений: не подсчитано");
+
+    this.occurrenceStudentSettingsWindow =
+        new OccurrenceStudentSettingsWindow(
+            gui,
+            student -> {
+              selectedStudent = student;
+
+              studentLabel.setText("Элемент для поиска: задан");
+            });
+
+    Panel panel = new Panel();
+    panel.setLayoutManager(new LinearLayout());
+
+    panel.addComponent(studentLabel);
+    panel.addComponent(occurrencesLabel);
+
+    panel.addComponent(new Button("Настроить элемент для поиска...", this::setupStudent));
+
+    panel.addComponent(new Button("Выполнить подсчёт", this::countOccurrences));
+
+    panel.addComponent(new Button("Выйти", this::close));
+
+    setComponent(panel);
+  }
+
+  private void setupStudent() {
+    occurrenceStudentSettingsWindow.showModal();
+  }
+
+  private void countOccurrences() {
+    MyList<Student> collection = state.getMainCollection();
+
+    if (collection == null || collection.isEmpty()) {
+      MessageWindow.showModal(gui, "Текущая коллекция пуста.");
+
+      return;
+    }
+
+    if (selectedStudent == null) {
+      MessageWindow.showModal(gui, "Сначала настройте элемент для поиска.");
+
+      return;
+    }
+
+    StudentOccurrenceIndexFinder finder = new StudentOccurrenceIndexFinder();
+
+    int[] occurrenceIndices = finder.findOccurrences(collection, selectedStudent);
+
+    occurrences = occurrenceIndices.length;
+
+    StringBuilder result = new StringBuilder();
+
+    result.append("Количество вхождений: ").append(occurrences);
+
+    result.append("\nИндексы: ");
+
+    if (occurrenceIndices.length == 0) {
+      result.append("нет");
+    } else {
+      for (int i = 0; i < occurrenceIndices.length; i++) {
+
+        if (i > 0) {
+          result.append(", ");
+        }
+
+        result.append(occurrenceIndices[i]);
+      }
+    }
+
+    occurrencesLabel.setText(result.toString());
+  }
+}

app/src/main/java/ru/project/ui/collection/counting/OccurrenceStudentSettingsWindow.java

@@ -0,0 +1,172 @@
+package ru.project.ui.collection.counting;
+
+import com.googlecode.lanterna.gui2.Button;
+import com.googlecode.lanterna.gui2.Label;
+import com.googlecode.lanterna.gui2.LinearLayout;
+import com.googlecode.lanterna.gui2.Panel;
+import com.googlecode.lanterna.gui2.WindowBasedTextGUI;
+import java.util.function.Consumer;
+import ru.project.student.Student;
+import ru.project.student.StudentBuilder;
+import ru.project.ui.base.BaseModalWindow;
+import ru.project.ui.common.InputValueWindow;
+import ru.project.ui.common.MessageWindow;
+
+public class OccurrenceStudentSettingsWindow extends BaseModalWindow {
+
+  private final StudentBuilder studentBuilder;
+  private final Consumer<Student> onApply;
+
+  private String groupNumber;
+  private Double averageGrade;
+  private Integer recordBookNumber;
+
+  private final Label groupNumberLabel;
+  private final Label averageGradeLabel;
+  private final Label recordBookNumberLabel;
+
+  public OccurrenceStudentSettingsWindow(WindowBasedTextGUI gui, Consumer<Student> onApply) {
+
+    super("Настройка элемента для поиска", gui);
+
+    this.studentBuilder = new StudentBuilder();
+    this.onApply = onApply;
+
+    Panel panel = new Panel();
+    panel.setLayoutManager(new LinearLayout());
+
+    groupNumberLabel = new Label("Номер группы: не задан");
+
+    averageGradeLabel = new Label("Средний балл: не задан");
+
+    recordBookNumberLabel = new Label("Номер зачётной книжки: не задан");
+
+    panel.addComponent(groupNumberLabel);
+    panel.addComponent(averageGradeLabel);
+    panel.addComponent(recordBookNumberLabel);
+
+    panel.addComponent(new Button("Задать номер группы...", this::setGroupNumber));
+
+    panel.addComponent(new Button("Задать средний балл...", this::setAverageGrade));
+
+    panel.addComponent(new Button("Задать номер зачётной книжки...", this::setRecordBookNumber));
+
+    panel.addComponent(new Button("Применить", this::apply));
+
+    panel.addComponent(new Button("Выйти", this::close));
+
+    setComponent(panel);
+  }
+
+  private void setGroupNumber() {
+    InputValueWindow window =
+        new InputValueWindow(
+            gui,
+            "Номер группы",
+            "Введите номер группы (например, A12):",
+            groupNumber,
+            value -> {
+              if (!value.matches(Student.getGroupNumberPattern())) {
+
+                MessageWindow.showModal(gui, "Номер группы должен соответствовать формату A12.");
+
+                return false;
+              }
+
+              groupNumber = value;
+              studentBuilder.setGroupNumber(value);
+
+              groupNumberLabel.setText("Номер группы: " + groupNumber);
+
+              return true;
+            });
+
+    window.showModal();
+  }
+
+  private void setAverageGrade() {
+    InputValueWindow window =
+        new InputValueWindow(
+            gui,
+            "Средний балл",
+            "Введите средний балл от 0.0 до 5.0:",
+            averageGrade == null ? null : String.valueOf(averageGrade),
+            value -> {
+              try {
+                double parsedValue = Double.parseDouble(value);
+
+                if (parsedValue < Student.getMinAverageGrade()
+                    || parsedValue > Student.getMaxAverageGrade()) {
+
+                  MessageWindow.showModal(gui, "Средний балл должен быть от 0.0 до 5.0.");
+
+                  return false;
+                }
+
+                averageGrade = parsedValue;
+                studentBuilder.setAverageGrade(parsedValue);
+
+                averageGradeLabel.setText("Средний балл: " + averageGrade);
+
+                return true;
+
+              } catch (NumberFormatException e) {
+                MessageWindow.showModal(gui, "Введите корректное число.");
+
+                return false;
+              }
+            });
+
+    window.showModal();
+  }
+
+  private void setRecordBookNumber() {
+    InputValueWindow window =
+        new InputValueWindow(
+            gui,
+            "Номер зачётной книжки",
+            "Введите номер зачётной книжки:",
+            recordBookNumber == null ? null : String.valueOf(recordBookNumber),
+            value -> {
+              try {
+                int parsedValue = Integer.parseInt(value);
+
+                if (parsedValue < Student.getMinRecordBookNumber()) {
+
+                  MessageWindow.showModal(gui, "Номер зачётной книжки должен быть положительным.");
+
+                  return false;
+                }
+
+                recordBookNumber = parsedValue;
+                studentBuilder.setRecordBookNumber(parsedValue);
+
+                recordBookNumberLabel.setText("Номер зачётной книжки: " + recordBookNumber);
+
+                return true;
+
+              } catch (NumberFormatException e) {
+                MessageWindow.showModal(gui, "Введите целое число.");
+
+                return false;
+              }
+            });
+
+    window.showModal();
+  }
+
+  private void apply() {
+    if (groupNumber == null || averageGrade == null || recordBookNumber == null) {
+
+      MessageWindow.showModal(gui, "Необходимо задать все поля элемента.");
+
+      return;
+    }
+
+    Student student = studentBuilder.build();
+
+    onApply.accept(student);
+
+    MessageWindow.showModal(gui, "Элемент для поиска успешно настроен.");
+  }
+}