document.addEventListener('DOMContentLoaded', function() {
    const switchRoleButton = document.getElementById('switch-role');
    const loginForm = document.getElementById('login-form');
    const usernameLabel = document.getElementById('username-label');
    const usernameInput = document.getElementById('username');
    const passwordInput = document.getElementById('password');
    const registerLinkHref = document.getElementById('register-link-href');

    let isTeacherLogin = false;

    // 切换角色按钮点击事件
    switchRoleButton.addEventListener('click', function() {
        isTeacherLogin = !isTeacherLogin;  // 切换状态
        toggleButtonColor(isTeacherLogin);
        toggleLoginFields(isTeacherLogin);
    });
    // 根据角色切换按钮背景色
    function toggleButtonColor(isTeacher) {
        if (isTeacher) {
            loginForm.classList.add('teacher-login');
        } else {
            loginForm.classList.remove('teacher-login');
        }
    }
    // 切换显示不同的表单字段
    function toggleLoginFields(isTeacher) {
        if (isTeacher) {
            // 显示教师登录字段
            usernameLabel.textContent = '教师用户名';
            switchRoleButton.textContent = '切换到学生登录'; // 更新按钮文本
            registerLinkHref.href = '/register_teacher';
            registerLinkHref.textContent = '注册新教师账号';
        } else {
            // 显示学生登录字段
            usernameLabel.textContent = '学生用户名';
            switchRoleButton.textContent = '切换到教师登录'; // 更新按钮文本
            registerLinkHref.href = '/register';
            registerLinkHref.textContent = '注册新学生账号';
        }
    }

    // 处理登录提交
    loginForm.addEventListener('submit', function(event) {
        event.preventDefault();  // 防止默认提交

        const username = usernameInput.value.trim();
        const password = passwordInput.value.trim();

        if (!username || !password) {
            alert('请填写所有必需的字段');
            return;
        }

        // 登录请求的 URL 依据角色不同而不同
        const loginUrl = isTeacherLogin ? '/login_teacher_post' : '/login_post';

        const data = isTeacherLogin ? { username, password } : { username, password };

        // 发送登录请求
        fetch(loginUrl, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify(data)  // 将数据发送到后端
        })
        .then(response => response.json())
        .then(data => {
            if (data.success) {
                // 登录成功，跳转到主页
                if (isTeacherLogin) {
                    window.location.href = '/teacherboard';
                } else {
                    window.location.href = '/dashboard';
                }
            } else {
                // 登录失败，提示错误信息
                alert('登录失败: ' + data.message);
            }
        })
        .catch(error => {
            console.error('Error:', error);
            alert('登录请求失败，请稍后重试');
        });
    });

});