/**
 * 统一请求封装
 */
const request = (() => {
    const BASE_URL = '/admin';

    /** 从 cookie 中获取 Token */
    function getToken() {
        const match = document.cookie.match(/(?:^|;\s*)Token=([^;]*)/);
        return match ? match[1] : '';
    }

    /** 统一请求方法 */
    async function http(url, options = {}) {
        const config = {
            headers: { 'Content-Type': 'application/json', 'Token': getToken(), ...options.headers },
            ...options
        };
        const response = await fetch(BASE_URL + url, config);

        // 401 未登录，跳转登录页
        if (response.status === 401) {
            window.location.href = BASE_URL + '/page/login';
            return Promise.reject('未登录');
        }

        // 解析响应体
        let result;
        try { result = await response.json(); } catch (e) {
            const msg = 'HTTP ' + response.status + ' 请求失败';
            ElementPlus ? ElementPlus.ElMessage.error(msg) : alert(msg);
            return Promise.reject(msg);
        }

        // 业务异常：code 不为 "0" 表示失败
        if (result.code !== '0') {
            const msg = result.msg || '请求失败';
            ElementPlus ? ElementPlus.ElMessage.error(msg) : alert(msg);
            return Promise.reject(msg);
        }

        return result.data;
    }

    return {
        get(url, params) {
            const query = params ? '?' + new URLSearchParams(params).toString() : '';
            return http(url + query, { method: 'GET' });
        },
        post(url, data) {
            return http(url, { method: 'POST', body: data != null ? JSON.stringify(data) : undefined });
        },
        put(url, data) {
            return http(url, { method: 'PUT', body: JSON.stringify(data) });
        },
        del(url, data) {
            return http(url, { method: 'DELETE', body: data ? JSON.stringify(data) : undefined });
        }
    };
})();