/**
 * API 客户端模块
 * 提供统一的 HTTP 请求封装和认证管理
 */

(function() {
    'use strict';
    
    /**
     * API 客户端类
     */
    class APIClient {
        constructor() {
            this.baseURL = window.API_CONFIG?.baseURL || '';
            this.version = window.API_CONFIG?.version || '/api';
            this.timeout = window.API_CONFIG?.timeout || 30000;
        }
        
        /**
         * 获取完整 URL
         */
        getUrl(endpoint) {
            return `${this.baseURL}${this.version}${endpoint}`;
        }
        
        /**
         * 获取认证 Token
         */
        getToken() {
            return localStorage.getItem('smart_center_token');
        }
        
        /**
         * 检查是否已登录
         */
        isAuthenticated() {
            const token = this.getToken();
            return !!token;
        }
        
        /**
         * 发送 HTTP 请求
         */
        async request(endpoint, options = {}) {
            const url = this.getUrl(endpoint);
            const headers = {
                'Content-Type': 'application/json',
                'Accept': 'application/json',
                ...options.headers
            };
            
            // 添加认证 Token
            const token = this.getToken();
            if (token) {
                headers['Authorization'] = `Bearer ${token}`;
            }
            
            try {
                const response = await fetch(url, {
                    ...options,
                    headers,
                    signal: AbortSignal.timeout(this.timeout)
                });
                
                const data = await response.json();
                
                if (!response.ok) {
                    throw new Error(data.message || `HTTP ${response.status}`);
                }
                
                return data;
            } catch (error) {
                console.error(`API 请求失败 [${endpoint}]:`, error);
                throw error;
            }
        }
        
        /**
         * GET 请求
         */
        async get(endpoint, params = {}) {
            const queryString = new URLSearchParams(params).toString();
            const url = queryString ? `${endpoint}?${queryString}` : endpoint;
            return this.request(url, { method: 'GET' });
        }
        
        /**
         * POST 请求
         */
        async post(endpoint, data = {}) {
            return this.request(endpoint, {
                method: 'POST',
                body: JSON.stringify(data)
            });
        }
        
        /**
         * PUT 请求
         */
        async put(endpoint, data = {}) {
            return this.request(endpoint, {
                method: 'PUT',
                body: JSON.stringify(data)
            });
        }
        
        /**
         * DELETE 请求
         */
        async delete(endpoint) {
            return this.request(endpoint, { method: 'DELETE' });
        }
        
        /**
         * 上传文件
         */
        async upload(endpoint, formData) {
            const url = this.getUrl(endpoint);
            const headers = {};
            
            const token = this.getToken();
            if (token) {
                headers['Authorization'] = `Bearer ${token}`;
            }
            
            try {
                const response = await fetch(url, {
                    method: 'POST',
                    headers,
                    body: formData,
                    signal: AbortSignal.timeout(this.timeout)
                });
                
                const data = await response.json();
                
                if (!response.ok) {
                    throw new Error(data.message || `HTTP ${response.status}`);
                }
                
                return data;
            } catch (error) {
                console.error(`文件上传失败 [${endpoint}]:`, error);
                throw error;
            }
        }
        
        /**
         * 登录
         */
        async login(username, password) {
            const data = await this.post('/auth/login', { username, password });
            if (data.token) {
                localStorage.setItem('smart_center_token', data.token);
            }
            return data;
        }
        
        /**
         * 注册
         */
        async register(userData) {
            return this.post('/auth/register', userData);
        }
        
        /**
         * 登出
         */
        async logout() {
            try {
                await this.post('/auth/logout');
            } finally {
                localStorage.removeItem('smart_center_token');
            }
        }
        
        /**
         * 获取用户信息
         */
        async getUserInfo() {
            return this.get('/user/info');
        }
        
        /**
         * 发送聊天消息
         */
        async sendMessage(message, attachments = []) {
            if (attachments.length > 0) {
                // 多模态消息
                const formData = new FormData();
                formData.append('message', message);
                for (const file of attachments) {
                    formData.append('files', file);
                }
                return this.upload('/chat/multimodal', formData);
            } else {
                // 纯文本消息
                return this.post('/chat/send', { message });
            }
        }
        
        /**
         * 获取模块列表
         */
        async getModuleList() {
            return this.get('/modules/list');
        }
        
        /**
         * 获取模块详情
         */
        async getModuleDetail(moduleName) {
            return this.get(`/modules/detail/${moduleName}`);
        }
    }
    
    // 创建全局实例
    window.APIClient = APIClient;
    window.apiClient = new APIClient();
    
    console.log('✅ APIClient 已加载');
})();