/**
 * 公用方法
 */

import fs from 'node:fs';
import { readdir, readFile } from 'node:fs/promises';
import { resolve } from 'node:path';
import md5 from 'md5';

class Common {

    //构造函数，设置默认配置
    constructor() {
        this.configDir = resolve('conf/');
    }

    sortDict(obj) {                         //dict按key排序
        return Object.keys(obj).sort().reduce(function (result, key) {
            result[key] = obj[key];
            return result;
        }, {});
    }

    joinDict(obj, glue, separator) {        //dict拼接成字符串
        if (typeof(glue) == 'undefined') {
            glue = '=';
        }

        if (typeof(separator) == 'undefined') {
            separator = '&';
        }

        return Object.keys(obj).map(function(key) {
            let arr = [key];
            let val = obj[key];
            if (typeof(val) == 'string' || typeof(val) == 'number') {
                arr.push(val);
            }else if (typeof(val) == 'object') {
                arr.push(JSON.stringify(val));
            }

            return arr.join(glue);
        }).join(separator);
    }

    sign(params, token) {                    //对参数做MD5签名
        return md5( JSON.stringify(this.sortDict(params)) + token );
    }

    //从conf/目录读取配置文件内容
    async getConfigFromJsonFile(filename) {
        let data = null;

        let filePath = this.configDir + `/${filename}`;
        if (fs.existsSync(filePath)) {
            try {
                const contents = await readFile(filePath, { encoding: 'utf8' });
                if (contents) {
                    data = JSON.parse(contents);
                }
            } catch (err) {
                console.error(`[FAILED] get config content from %s failed, error: %s`, filePath, err.message);
            }
        }else {
            console.error("[ERROR] file %s not exist.", filePath);
        }

        return data;
    }

}

let commonFuns = new Common();
export default commonFuns;