feat: implement composite pattern for student search

app/src/main/java/ru/project/search/AverageGradeRangeCriteria.java

@@ -0,0 +1,22 @@
+package ru.project.search;
+
+import ru.project.student.Student;
+
+public class AverageGradeRangeCriteria implements StudentSearchCriteria {
+    private final double min;
+    private final double max;
+
+    public AverageGradeRangeCriteria(double min, double max) {
+        if (min > max) {
+            throw new IllegalArgumentException("Min grade must be <= max grade");
+        }
+        this.min = min;
+        this.max = max;
+    }
+
+    @Override
+    public boolean matches(Student student) {
+        double grade = student.getAverageGrade();
+        return grade >= min && grade <= max;
+    }
+}

app/src/main/java/ru/project/search/CompositeStudentSearchCriteria.java

@@ -0,0 +1,51 @@
+package ru.project.search;
+
+import ru.project.student.Student;
+import java.util.ArrayList;
+import java.util.List;
+
+public class CompositeStudentSearchCriteria implements StudentSearchCriteria {
+    private final SearchOperation operation;
+    private final List<StudentSearchCriteria> criteriaList = new ArrayList<>();
+
+    public CompositeStudentSearchCriteria(SearchOperation operation) {
+        if (operation == null) {
+            throw new IllegalArgumentException("Operation must not be null");
+        }
+        this.operation = operation;
+    }
+
+    public void add(StudentSearchCriteria criteria) {
+        if (criteria == null) {
+            throw new IllegalArgumentException("Criteria must not be null");
+        }
+        criteriaList.add(criteria);
+    }
+
+    public void remove(StudentSearchCriteria criteria) {
+        criteriaList.remove(criteria);
+    }
+
+    @Override
+    public boolean matches(Student student) {
+        if (criteriaList.isEmpty()) {
+            return operation == SearchOperation.INTERSECTION;
+        }
+
+        if (operation == SearchOperation.UNION) {
+            for (StudentSearchCriteria c : criteriaList) {
+                if (c.matches(student)) {
+                    return true;
+                }
+            }
+            return false;
+        } else {
+            for (StudentSearchCriteria c : criteriaList) {
+                if (!c.matches(student)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+}

app/src/main/java/ru/project/search/GroupNumberRangeCriteria.java

@@ -0,0 +1,25 @@
+package ru.project.search;
+
+import ru.project.student.Student;
+
+public class GroupNumberRangeCriteria implements StudentSearchCriteria {
+    private final String min;
+    private final String max;
+
+    public GroupNumberRangeCriteria(String min, String max) {
+        if (min == null || max == null) {
+            throw new IllegalArgumentException("Min and max must not be null");
+        }
+        if (min.compareTo(max) > 0) {
+            throw new IllegalArgumentException("Min group must be <= max group");
+        }
+        this.min = min;
+        this.max = max;
+    }
+
+    @Override
+    public boolean matches(Student student) {
+        String group = student.getGroupNumber();
+        return group.compareTo(min) >= 0 && group.compareTo(max) <= 0;
+    }
+}

app/src/main/java/ru/project/search/RecordBookNumberRangeCriteria.java

@@ -0,0 +1,22 @@
+package ru.project.search;
+
+import ru.project.student.Student;
+
+public class RecordBookNumberRangeCriteria implements StudentSearchCriteria {
+    private final int min;
+    private final int max;
+
+    public RecordBookNumberRangeCriteria(int min, int max) {
+        if (min > max) {
+            throw new IllegalArgumentException("Min record number must be <= max");
+        }
+        this.min = min;
+        this.max = max;
+    }
+
+    @Override
+    public boolean matches(Student student) {
+        int number = student.getRecordBookNumber();
+        return number >= min && number <= max;
+    }
+}

app/src/main/java/ru/project/search/SearchOperation.java

@@ -0,0 +1,6 @@
+package ru.project.search;
+
+public enum SearchOperation {
+    UNION,
+    INTERSECTION
+}

app/src/main/java/ru/project/search/StudentSearchCriteria.java

@@ -0,0 +1,7 @@
+package ru.project.search;
+
+import ru.project.student.Student;
+
+public interface StudentSearchCriteria {
+    boolean matches(Student student);
+}

app/src/main/java/ru/project/search/StudentSearchService.java

@@ -0,0 +1,30 @@
+package ru.project.search;
+
+import ru.project.list.MyList;
+import ru.project.list.MyLinkedList;
+import ru.project.student.Student;
+
+public class StudentSearchService {
+    private final StudentSearchCriteria criteria;
+
+    public StudentSearchService(StudentSearchCriteria criteria) {
+        if (criteria == null) {
+            throw new IllegalArgumentException("Criteria must not be null");
+        }
+        this.criteria = criteria;
+    }
+
+    public MyList<Student> find(MyList<Student> students) {
+        if (students == null) {
+            return new MyLinkedList<>();
+        }
+        MyList<Student> result = new MyLinkedList<>();
+        for (int i = 0; i < students.size(); i++) {
+            Student s = students.get(i);
+            if (criteria.matches(s)) {
+                result.add(s);
+            }
+        }
+        return result;
+    }
+}