/**
 * 云酒馆 - 用户认证模块
 * 处理用户登录和注册功能
 */

// ===== 配置 =====
const CONFIG = {
    API_BASE_URL: 'http://localhost:8888/app',
    TOKEN_KEY: 'st_access_token',
    REFRESH_TOKEN_KEY: 'st_refresh_token',
    USER_KEY: 'st_user_info',
};

// ===== DOM 元素 =====
const elements = {
    tabs: document.querySelectorAll('.auth-tab'),
    loginForm: document.getElementById('loginForm'),
    registerForm: document.getElementById('registerForm'),
    messageBox: document.getElementById('messageBox'),
    loadingOverlay: document.getElementById('loadingOverlay'),
    passwordToggles: document.querySelectorAll('.password-toggle'),
};

// ===== 初始化 =====
document.addEventListener('DOMContentLoaded', () => {
    initTabs();
    initForms();
    initPasswordToggles();
    checkAutoLogin();
});

// ===== 标签页切换 =====
function initTabs() {
    elements.tabs.forEach(tab => {
        tab.addEventListener('click', () => {
            const tabName = tab.dataset.tab;
            switchTab(tabName);
        });
    });
}

function switchTab(tabName) {
    // 更新标签页状态
    elements.tabs.forEach(tab => {
        tab.classList.toggle('active', tab.dataset.tab === tabName);
    });

    // 更新表单显示
    elements.loginForm.classList.toggle('active', tabName === 'login');
    elements.registerForm.classList.toggle('active', tabName === 'register');

    // 清空消息
    hideMessage();
}

// ===== 表单初始化 =====
function initForms() {
    // 登录表单
    elements.loginForm.addEventListener('submit', async (e) => {
        e.preventDefault();
        await handleLogin();
    });

    // 注册表单
    elements.registerForm.addEventListener('submit', async (e) => {
        e.preventDefault();
        await handleRegister();
    });
}

// ===== 密码显示/隐藏切换 =====
function initPasswordToggles() {
    elements.passwordToggles.forEach(toggle => {
        toggle.addEventListener('click', () => {
            const targetId = toggle.dataset.target;
            const input = document.getElementById(targetId);
            const icon = toggle.querySelector('i');

            if (input.type === 'password') {
                input.type = 'text';
                icon.classList.remove('fa-eye');
                icon.classList.add('fa-eye-slash');
            } else {
                input.type = 'password';
                icon.classList.remove('fa-eye-slash');
                icon.classList.add('fa-eye');
            }
        });
    });
}

// ===== 登录处理 =====
async function handleLogin() {
    const username = document.getElementById('loginUsername').value.trim();
    const password = document.getElementById('loginPassword').value;
    const rememberMe = document.getElementById('rememberMe').checked;

    // 验证输入
    if (!username || !password) {
        showMessage('请填写完整的登录信息', 'error');
        return;
    }

    showLoading();

    try {
        const response = await fetch(`${CONFIG.API_BASE_URL}/auth/login`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({ username, password }),
        });

        const data = await response.json();

        if (data.code === 0) {
            // 登录成功
            saveLoginData(data.data, rememberMe);
            showMessage('登录成功！正在跳转...', 'success');
            
            // 延迟跳转到主页
            setTimeout(() => {
                window.location.href = '/';
            }, 1500);
        } else {
            // 登录失败
            showMessage(data.msg || '登录失败，请检查用户名和密码', 'error');
        }
    } catch (error) {
        console.error('登录错误:', error);
        showMessage('网络错误，请检查服务器连接', 'error');
    } finally {
        hideLoading();
    }
}

// ===== 注册处理 =====
async function handleRegister() {
    const username = document.getElementById('registerUsername').value.trim();
    const password = document.getElementById('registerPassword').value;
    const passwordConfirm = document.getElementById('registerPasswordConfirm').value;
    const nickName = document.getElementById('registerNickname').value.trim();
    const email = document.getElementById('registerEmail').value.trim();

    // 验证输入
    if (!username || !password || !passwordConfirm) {
        showMessage('请填写必填信息', 'error');
        return;
    }

    if (username.length < 3 || username.length > 32) {
        showMessage('用户名长度应为 3-32 个字符', 'error');
        return;
    }

    if (password.length < 6 || password.length > 32) {
        showMessage('密码长度应为 6-32 个字符', 'error');
        return;
    }

    if (password !== passwordConfirm) {
        showMessage('两次输入的密码不一致', 'error');
        return;
    }

    // 验证用户名格式
    if (!/^[a-zA-Z0-9_]+$/.test(username)) {
        showMessage('用户名只能包含字母、数字和下划线', 'error');
        return;
    }

    showLoading();

    try {
        const requestBody = {
            username,
            password,
            nickName: nickName || username, // 如果没有昵称，使用用户名
        };

        // 如果填写了邮箱，添加到请求中
        if (email) {
            requestBody.email = email;
        }

        const response = await fetch(`${CONFIG.API_BASE_URL}/auth/register`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify(requestBody),
        });

        const data = await response.json();

        if (data.code === 0) {
            // 注册成功
            showMessage('注册成功！请登录', 'success');
            
            // 清空注册表单
            elements.registerForm.reset();
            
            // 切换到登录标签页，并填充用户名
            setTimeout(() => {
                switchTab('login');
                document.getElementById('loginUsername').value = username;
                document.getElementById('loginPassword').focus();
            }, 1500);
        } else {
            // 注册失败
            showMessage(data.msg || '注册失败，请稍后重试', 'error');
        }
    } catch (error) {
        console.error('注册错误:', error);
        showMessage('网络错误，请检查服务器连接', 'error');
    } finally {
        hideLoading();
    }
}

// ===== 保存登录数据 =====
function saveLoginData(loginData, rememberMe) {
    const { token, refreshToken, user } = loginData;

    // 保存到 localStorage 或 sessionStorage
    const storage = rememberMe ? localStorage : sessionStorage;

    storage.setItem(CONFIG.TOKEN_KEY, token);
    storage.setItem(CONFIG.REFRESH_TOKEN_KEY, refreshToken);
    storage.setItem(CONFIG.USER_KEY, JSON.stringify(user));
}

// ===== 自动登录检查 =====
function checkAutoLogin() {
    // 检查是否已经登录
    const token = localStorage.getItem(CONFIG.TOKEN_KEY) || 
                  sessionStorage.getItem(CONFIG.TOKEN_KEY);

    if (token) {
        // 已登录，尝试验证 token 是否有效
        verifyToken(token);
    }
}

// ===== 验证 Token =====
async function verifyToken(token) {
    try {
        const response = await fetch(`${CONFIG.API_BASE_URL}/auth/userinfo`, {
            method: 'GET',
            headers: {
                'x-token': token,
            },
        });

        if (response.ok) {
            const data = await response.json();
            if (data.code === 0) {
                // Token 有效，直接跳转到主页
                showMessage('检测到已登录，正在跳转...', 'success');
                setTimeout(() => {
                    window.location.href = '/';
                }, 1000);
            }
        }
    } catch (error) {
        console.error('Token 验证失败:', error);
        // Token 无效，清除存储
        clearLoginData();
    }
}

// ===== 清除登录数据 =====
function clearLoginData() {
    localStorage.removeItem(CONFIG.TOKEN_KEY);
    localStorage.removeItem(CONFIG.REFRESH_TOKEN_KEY);
    localStorage.removeItem(CONFIG.USER_KEY);
    sessionStorage.removeItem(CONFIG.TOKEN_KEY);
    sessionStorage.removeItem(CONFIG.REFRESH_TOKEN_KEY);
    sessionStorage.removeItem(CONFIG.USER_KEY);
}

// ===== 消息提示 =====
function showMessage(message, type = 'error') {
    elements.messageBox.textContent = message;
    elements.messageBox.className = `message-box show ${type}`;
    
    // 3秒后自动隐藏
    setTimeout(() => {
        hideMessage();
    }, 5000);
}

function hideMessage() {
    elements.messageBox.classList.remove('show');
}

// ===== 加载动画 =====
function showLoading() {
    elements.loadingOverlay.classList.add('show');
}

function hideLoading() {
    elements.loadingOverlay.classList.remove('show');
}

// ===== 工具函数：获取当前登录用户 =====
export function getCurrentUser() {
    const userJson = localStorage.getItem(CONFIG.USER_KEY) || 
                     sessionStorage.getItem(CONFIG.USER_KEY);
    return userJson ? JSON.parse(userJson) : null;
}

// ===== 工具函数：获取 Token =====
export function getToken() {
    return localStorage.getItem(CONFIG.TOKEN_KEY) || 
           sessionStorage.getItem(CONFIG.TOKEN_KEY);
}

// ===== 工具函数：登出 =====
export async function logout() {
    const token = getToken();
    
    if (token) {
        try {
            await fetch(`${CONFIG.API_BASE_URL}/auth/logout`, {
                method: 'POST',
                headers: {
                    'x-token': token,
                },
            });
        } catch (error) {
            console.error('登出请求失败:', error);
        }
    }

    clearLoginData();
    window.location.href = '/auth.html';
}

// ===== 导出配置供其他模块使用 =====
export { CONFIG };