package com.studentmanagement;

import com.studentmanagement.controller.StudentController;
import com.studentmanagement.model.Student;
import com.studentmanagement.exception.StudentNotFoundException;
import com.studentmanagement.exception.DuplicateStudentException;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import java.util.List;
import static org.junit.jupiter.api.Assertions.*;

/**
 * 学生管理系统测试类
 * 测试Model和Controller层的核心功能
 */
public class StudentManagementTest {
    private StudentController controller;

    @BeforeEach
    void setUp() {
        // 每个测试方法执行前初始化控制器
        controller = new StudentController();
    }

    @Test
    void testGetAllStudents() {
        // 测试获取所有学生
        List<Student> students = controller.getAllStudents();
        assertNotNull(students);
        // 初始数据有3个学生
        assertTrue(students.size() >= 3);
    }

    @Test
    void testGetStudentById_Found() throws StudentNotFoundException {
        // 测试根据ID查找存在的学生
        Student student = controller.getStudentById(1);
        assertNotNull(student);
        assertEquals(1, student.getId());
        assertEquals("张三", student.getName());
    }

    @Test
    void testGetStudentById_NotFound() {
        // 测试根据ID查找不存在的学生
        assertThrows(StudentNotFoundException.class, () -> {
            controller.getStudentById(999);
        });
    }

    @Test
    void testAddStudent_Success() throws DuplicateStudentException {
        // 测试添加新学生成功
        Student newStudent = new Student(10, "测试学生", 22, "软件工程", 88.0);
        controller.addStudent(newStudent);
        
        // 验证学生是否添加成功
        try {
            Student addedStudent = controller.getStudentById(10);
            assertNotNull(addedStudent);
            assertEquals("测试学生", addedStudent.getName());
        } catch (StudentNotFoundException e) {
            fail("学生添加失败，找不到添加的学生");
        }
    }

    @Test
    void testAddStudent_Duplicate() throws DuplicateStudentException {
        // 测试添加重复ID的学生
        Student student1 = new Student(20, "重复测试1", 23, "数据库", 92.0);
        controller.addStudent(student1);
        
        // 尝试添加相同ID的学生
        Student student2 = new Student(20, "重复测试2", 24, "网络", 85.0);
        assertThrows(DuplicateStudentException.class, () -> {
            controller.addStudent(student2);
        });
    }

    @Test
    void testUpdateStudent_Success() throws StudentNotFoundException, DuplicateStudentException {
        // 先添加一个学生用于测试更新
        Student student = new Student(30, "待更新学生", 20, "Java基础", 75.0);
        controller.addStudent(student);
        
        // 更新学生信息
        Student updatedStudent = new Student(30, "已更新学生", 21, "Java高级", 85.0);
        controller.updateStudent(updatedStudent);
        
        // 验证更新是否成功
        Student retrievedStudent = controller.getStudentById(30);
        assertEquals("已更新学生", retrievedStudent.getName());
        assertEquals(21, retrievedStudent.getAge());
        assertEquals("Java高级", retrievedStudent.getCourse());
        assertEquals(85.0, retrievedStudent.getGrade());
    }

    @Test
    void testUpdateStudent_NotFound() {
        // 测试更新不存在的学生
        Student student = new Student(999, "不存在的学生", 22, "测试课程", 80.0);
        assertThrows(StudentNotFoundException.class, () -> {
            controller.updateStudent(student);
        });
    }

    @Test
    void testDeleteStudent_Success() throws StudentNotFoundException, DuplicateStudentException {
        // 先添加一个学生用于测试删除
        Student student = new Student(40, "待删除学生", 22, "测试课程", 78.0);
        controller.addStudent(student);
        
        // 删除学生
        controller.deleteStudent(40);
        
        // 验证删除是否成功
        assertThrows(StudentNotFoundException.class, () -> {
            controller.getStudentById(40);
        });
    }

    @Test
    void testDeleteStudent_NotFound() {
        // 测试删除不存在的学生
        assertThrows(StudentNotFoundException.class, () -> {
            controller.deleteStudent(999);
        });
    }

    @Test
    void testGetStudentsByCourse() {
        // 测试根据课程查找学生
        List<Student> javaStudents = controller.getStudentsByCourse("Java编程");
        assertNotNull(javaStudents);
        // 初始数据中应该有一个Java编程的学生
        assertTrue(javaStudents.size() >= 1);
        
        // 验证所有返回的学生都是Java编程课程
        for (Student student : javaStudents) {
            assertTrue(student.getCourse().equalsIgnoreCase("Java编程"));
        }
    }

    @Test
    void testGetStudentsByGradeAbove() {
        // 测试查找成绩高于指定分数的学生
        List<Student> highGradeStudents = controller.getStudentsByGradeAbove(88.0);
        assertNotNull(highGradeStudents);
        
        // 验证所有返回的学生成绩都高于等于88.0
        for (Student student : highGradeStudents) {
            assertTrue(student.getGrade() >= 88.0);
        }
    }

    @Test
    void testCalculateAverageGradeByCourse() {
        // 测试计算课程平均成绩
        double avgGrade = controller.calculateAverageGradeByCourse("Java编程");
        // 初始数据中Java编程的学生成绩为85.5
        assertTrue(avgGrade > 0);
    }

    @Test
    void testCalculateAverageAge() {
        // 测试计算平均年龄
        double avgAge = controller.calculateAverageAge();
        assertTrue(avgAge > 0);
    }
}