package test.dao.impl;

import dao.impl.LeaveRequestDAOImpl;
import dao.impl.StudentDAOImpl;
import model.ApprovalStatus;
import model.LeaveRequest;
import model.Student;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import util.DatabaseUtil;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Date;
import java.util.List;

import static org.junit.Assert.*;

/**
 * LeaveRequestDAOImpl的单元测试类
 * 测试请假申请数据访问层的各项功能
 */
public class LeaveRequestDAOImplTest {
    
    private LeaveRequestDAOImpl leaveRequestDAO;
    private StudentDAOImpl studentDAO;
    private Student testStudent;
    
    @Before
    public void setUp() throws SQLException {
        leaveRequestDAO = new LeaveRequestDAOImpl();
        studentDAO = new StudentDAOImpl();
        
        // 清理测试数据
        cleanTestData();
        
        // 创建测试用学生
        testStudent = createAndInsertTestStudent();
    }
    
    @After
    public void tearDown() throws SQLException {
        cleanTestData();
    }
    
    /**
     * 清理测试数据
     */
    private void cleanTestData() throws SQLException {
        try (Connection conn = DatabaseUtil.getConnection()) {
            // 删除请假记录
            try (PreparedStatement stmt = conn.prepareStatement("DELETE FROM leave_requests WHERE student_id IN (SELECT id FROM students WHERE student_id = ?)")) {
                stmt.setString(1, "2024001");
                stmt.executeUpdate();
            }
            
            // 删除测试学生
            try (PreparedStatement stmt = conn.prepareStatement("DELETE FROM students WHERE student_id = ?")) {
                stmt.setString(1, "2024001");
                stmt.executeUpdate();
            }
        }
    }
    
    /**
     * 创建并插入测试用的Student对象
     */
    private Student createAndInsertTestStudent() {
        Student student = new Student();
        student.setStudentId("2024001");
        student.setName("张三");
        student.setClassName("计算机科学与技术1班");
        student.setContact("13800138000");
        student.setCollege("信息科学与工程学院");
        student.setMajor("计算机科学与技术");
        student.setPassword("password123");
        
        studentDAO.insert(student);
        return student;
    }
    
    /**
     * 创建测试用的LeaveRequest对象
     */
    private LeaveRequest createTestLeaveRequest() {
        LeaveRequest request = new LeaveRequest();
        request.setStudent(testStudent);
        request.setStartTime(new Date());
        request.setEndTime(new Date(System.currentTimeMillis() + 86400000)); // 一天后
        request.setStatus(ApprovalStatus.PENDING);
        request.setDuration(24.0);
        request.setLocation("北京市海淀区");
        request.setReasonType("事假");
        request.setReasonDetail("参加亲属婚礼");
        request.setLeavingCity(false);
        request.setRequestTime(new Date());
        return request;
    }
    
    @Test
    public void testInsert() {
        // 准备测试数据
        LeaveRequest request = createTestLeaveRequest();
        
        // 执行插入操作
        int result = leaveRequestDAO.insert(request);
        
        // 验证结果
        assertEquals(1, result);
        assertTrue(request.getId() > 0);
        
        // 验证数据是否正确插入
        List<LeaveRequest> requests = leaveRequestDAO.findByStudentId(testStudent.getId());
        assertFalse(requests.isEmpty());
        
        LeaveRequest foundRequest = requests.get(0);
        assertEquals(request.getStudent().getId(), foundRequest.getStudent().getId());
        assertEquals(request.getStatus(), foundRequest.getStatus());
        assertEquals(request.getLocation(), foundRequest.getLocation());
        assertEquals(request.getReasonType(), foundRequest.getReasonType());
        assertEquals(request.getReasonDetail(), foundRequest.getReasonDetail());
        assertEquals(request.isLeavingCity(), foundRequest.isLeavingCity());
    }
    
    @Test
    public void testFindByStudentId() {
        // 准备测试数据
        LeaveRequest request1 = createTestLeaveRequest();
        LeaveRequest request2 = createTestLeaveRequest();
        
        leaveRequestDAO.insert(request1);
        leaveRequestDAO.insert(request2);
        
        // 执行查询操作
        List<LeaveRequest> requests = leaveRequestDAO.findByStudentId(testStudent.getId());
        
        // 验证结果
        assertEquals(2, requests.size());
        for (LeaveRequest request : requests) {
            assertEquals(testStudent.getId(), request.getStudent().getId());
            assertEquals(testStudent.getName(), request.getStudent().getName());
        }
    }
    
    @Test
    public void testFindByStudentIdNotFound() {
        // 查询不存在的学生ID
        List<LeaveRequest> requests = leaveRequestDAO.findByStudentId(-1);
        
        // 验证结果
        assertTrue(requests.isEmpty());
    }
    
    @Test
    public void testInsertWithNullStudent() {
        // 准备测试数据
        LeaveRequest request = createTestLeaveRequest();
        request.setStudent(null);
        
        // 执行插入操作
        int result = leaveRequestDAO.insert(request);
        
        // 验证结果
        assertEquals(0, result);
    }
    
    @Test
    public void testUpdateStatus() {
        // 准备测试数据
        LeaveRequest request = createTestLeaveRequest();
        leaveRequestDAO.insert(request);
        
        // 执行更新操作
        String comment = "同意请假申请";
        int result = leaveRequestDAO.updateStatus(request.getId(), ApprovalStatus.APPROVED, comment);
        
        // 验证结果
        assertEquals(1, result);
        
        // 验证状态是否正确更新
        List<LeaveRequest> requests = leaveRequestDAO.findByStudentId(testStudent.getId());
        assertFalse(requests.isEmpty());
        LeaveRequest updatedRequest = requests.get(0);
        assertEquals(ApprovalStatus.APPROVED, updatedRequest.getStatus());
        assertEquals(comment, updatedRequest.getApproverComment());
    }
    
    @Test
    public void testUpdateStatusNotFound() {
        // 测试更新不存在的记录
        int result = leaveRequestDAO.updateStatus(-1, ApprovalStatus.APPROVED, "测试评论");
        
        // 验证结果
        assertEquals(0, result);
    }
}