import { RedisClientType } from '@redis/client';
import Crypto, { CipherKey } from 'crypto';
// eslint-disable-next-line @typescript-eslint/no-var-requires
const XML2JS = require(`xml2js`);
// eslint-disable-next-line @typescript-eslint/no-var-requires
// const random = require('string-random')
const randomStr = (length?:number,nonum?:boolean)=>{
    let arr = '1234567890abcdefghijklmnopqrstuvwxyz';
    if(nonum) arr = 'abcdefghijklmnopqrstuvwxyz';
    let str = '';
    length = length?length:3;
    for(let i = 0;i<length;i++){
        str += arr.substr(Math.floor(Math.random()*26),1);
    }
    return str;
}

const WechatMchDomain  = `https://api.mch.weixin.qq.com`;

class WechatMchSDK{
    private _redisClient;
    private _mchId;
    private _appId;
    private _privateKeyPem;
    private _privateCertPem;
    private _privateKeySerial;
    private _privateAPIV3Key;
    private _privateAPIKey;
    private _wechatMchApiURL;
    constructor(redisInstance:RedisClientType,config:any){
        this._redisClient = redisInstance;
        this._mchId = config.mchId;
        this._appId = config.appId;
        this._privateKeyPem = null;
        this._privateCertPem = null;
        this._privateKeySerial = config.privateKeySerial;
        this._privateAPIV3Key = config.privateAPIV3Key;
        this._privateAPIKey = config.privateAPIKey;
        if(config.privateKeyFilePath){
            this._privateKeyPem = FILE.readFileSync(config.privateKeyFilePath,'utf8');
            this._privateCertPem = FILE.readFileSync(config.privateCertFilePath,'utf8');
            if(!this._privateKeyPem){
                throw new Error('[Wechat-Mch-SDK] Config private key pem file read error');
            }
            if(!this._privateCertPem){
                throw new Error('[Wechat-Mch-SDK] Config private key pem file read error');
            }
        }
        if(config.privateKeyPEM){
            this._privateKeyPem = config.privateKeyPEM;
        }
        
        if(!this._privateKeyPem){
            throw new Error('[Wechat-Mch-SDK] Private Key read error');
        }

        this._wechatMchApiURL = {
            orderTrade_JsAPI:`${WechatMchDomain}/v3/pay/transactions/jsapi`,
            businessPay_To_Openid:`${WechatMchDomain}/mmpaymkttransfers/promotion/transfers`,
            getPlatformCertificates:`${WechatMchDomain}/v3/certificates`,
            
        }

    }

    getPlatformCertificates(){
        return new Promise(async (resolve,reject)=>{
            const certificate = await this._redisClient.get(`WECHAT_MCH_${this._mchId}_PLATFORM_CERT`);
            if(certificate) return resolve(certificate);
            const result = await this._getNewPlatformCertificates();
            const cert = result.cert;
            
            if(cert){
                await this._redisClient.set(`WECHAT_MCH_${this._mchId}_PLATFORM_CERT`,cert.certificate);
                await this._redisClient.expire(`WECHAT_MCH_${this._mchId}_PLATFORM_CERT`,7200);
                resolve(cert.certificate);
            }else{
                resolve(null);
            }
        });
    }
    async _getNewPlatformCertificates(){
        const signedObj = this.makeSignRequestData(this._wechatMchApiURL.getPlatformCertificates,'GET','');
        const getPlatformCertsResult = await this._requestMchV3Api(this._wechatMchApiURL.getPlatformCertificates,'GET',signedObj.timestamp,signedObj.nonce_str,'',signedObj.signature) as AnyKeyString;
        if(getPlatformCertsResult.statusCode==200){
            const cert = getPlatformCertsResult.data.data[0];
            const certContent = this._decryptByV3Key(cert.encrypt_certificate.ciphertext,cert.encrypt_certificate.nonce,cert.encrypt_certificate.associated_data);
            const certSerial = cert.serial_no;
            return({cert:{serial:certSerial,certificate:certContent}});
        }else{
            LOGGER.error('Get new platform certificates failed');
            LOGGER.error(getPlatformCertsResult.toString());
            return({cert:null});
        }            
    }

    async orderTrade_JSAPI(openid:string,trade_no:string,amount:number,desc:string,expire_unix_timestamp:number,notify_url:string){
        const postData = {
            appid:this._appId,
            mchid:this._mchId,
            description:desc,
            out_trade_no:trade_no,
            time_expire:Moment.unix(expire_unix_timestamp).format(),
            notify_url:notify_url,
            amount:{
                total:amount,
                currency:'CNY'
            },
            payer:{
                openid:openid
            }
        };
        const originBody = JSON.stringify(postData);
        const signedObj = this.makeSignRequestData(this._wechatMchApiURL.orderTrade_JsAPI,'POST',postData);
        const result = await this._requestMchV3Api(this._wechatMchApiURL.orderTrade_JsAPI,'POST',signedObj.timestamp,signedObj.nonce_str,originBody,signedObj.signature) as AnyKeyString;
        if(result.statusCode==200){
            return result.data.prepay_id;
        }else{
            LOGGER.error('Wechat Mch orderTrade error:');
            LOGGER.error(JSON.stringify(result));
            return null;
        }
    }

    businessPay_To_Openid(orderid:string,openid:string,amount:number,desc:string){
        return new Promise(resolve=>{
            const postDataArr:any[] = [];
            const postData:AnyKeyString = {
                mch_appid:  this._appId,
                mchid:      this._mchId,
                nonce_str:  randomStr(32).toUpperCase(),
                partner_trade_no: orderid,
                openid,
                check_name: 'NO_CHECK',
                amount,
                desc
            }
            Object.keys(postData).forEach(key=>{
                postDataArr.push(`${key}=${postData[key]}`);
            });
            postDataArr.sort();
            let postStr = postDataArr.join('&');
            postStr += `&key=${this._privateAPIKey}`;
            const md5 = Crypto.createHash('md5')
            postData.sign = md5.update(postStr).digest('hex').toUpperCase();

            let postXml = '<xml>';
            Object.keys(postData).forEach(key=>{
                postXml += `<${key}>${postData[key]}</${key}>`;
            });
            postXml += '</xml>'

            REQUEST({url:this._wechatMchApiURL.businessPay_To_Openid,method:'POST',body:postXml,encoding:'utf-8',cert:this._privateCertPem,key:this._privateKeyPem},(err:any,response:any,body:any)=>{
                const x2jparser = XML2JS.parseString;
                x2jparser(body, function (err:any, result:any) {
                    if(result.xml && result.xml.result_code[0]!='SUCCESS'){
                        return resolve({err:result.xml.err_code[0],data:result.xml.err_code_des[0]})
                    }
                    resolve({err:null,data:'SUCCESS'});
                });
            })
        });
        
    }

    makeSignPaymentData(prepayId:string){
        const randStr = randomStr(32).toUpperCase(),timeStamp = Moment().unix(),packageStr = `prepay_id=${prepayId}`;
        let preStr = ''
        preStr += `${this._appId}\n`;
        preStr += `${timeStamp}\n`;
        preStr += `${randStr}\n`;
        preStr += `${packageStr}\n`;
        // console.log(preStr)
        const signedStr = this._signWithRSASHA256(preStr);
        // console.log(signedStr)
        return {timeStamp:`${timeStamp}`,nonceStr:randStr,paySign:signedStr,package:packageStr,signType:'RSA'};
    }

    makeSignRequestData(requestUrl:string,method:string,content:AnyKeyString|string){
        const randStr = randomStr(32).toUpperCase(),timestamp = Moment().unix();
        const url = new URL(requestUrl);
        const postData = (typeof content === 'object')?JSON.stringify(content):content;
        let preStr = ''
        preStr += `${method.toUpperCase()}\n`;
        preStr += `${url.pathname}${url.search}\n`;
        preStr += `${timestamp}\n`;
        preStr += `${randStr}\n`;
        preStr += `${postData}\n`;
        // console.log(preStr)
        const signedStr = this._signWithRSASHA256(preStr);
        // console.log(signedStr)
        return {origin:preStr,timestamp,nonce_str:randStr,signature:signedStr};
    }

    callbackDecrypt(ciphertext:string,nonce:string,associatedData:string){
        const result = this._decryptByV3Key(ciphertext,nonce,associatedData);
        return result;
    }

    _signWithRSASHA256(data:string){
        const signObj = Crypto.createSign('RSA-SHA256')
        signObj.update(data);
        const signedStr = signObj.sign(this._privateKeyPem,'base64');
        return signedStr;
    }
    _requestMchV3Api(url:string,method:string,timestamp:number,nonce_str:string,originBody:string|AnyKeyString,signature:string){
        return new Promise((resolve,reject)=>{
            const Authorization = `WECHATPAY2-SHA256-RSA2048 mchid="${this._mchId}",nonce_str="${nonce_str}",signature="${signature}",timestamp="${timestamp}",serial_no="${this._privateKeySerial}"`;
            REQUEST({url:url,method,encoding:'utf-8',jsonReviver: true,body:originBody,headers: {
                'Content-Type'  : 'application/json',
                'Accept'        : 'application/json',
                'User-Agent'    : 'WECHAT_MCH_SDK/v1',
                'Authorization' : Authorization,
            }},(err:any,response:any,body:any)=>{
                // console.log(response.headers,body)
                if(typeof body ==='string'){
                    try{
                        body = JSON.parse(body);
                    }catch(e){}
                }
                resolve({statusCode:response.statusCode,data:body});
            });
        });
    }

    _decryptByV3Key(ciphertext:string,nonce:string,associatedData:string){
        const ciphertextBuffer = Buffer.from(ciphertext, 'base64')
        const authTag = ciphertextBuffer.slice(ciphertextBuffer.length - 16)
        const data = ciphertextBuffer.slice(0, ciphertextBuffer.length - 16)
        const decipherIv = Crypto.createDecipheriv('aes-256-gcm', this._privateAPIV3Key, nonce)
        decipherIv.setAuthTag(Buffer.from(authTag))
        decipherIv.setAAD(Buffer.from(associatedData))
        let decryptStr = decipherIv.update(data, undefined, 'utf8')
        decipherIv.final();
        if(typeof decryptStr == 'string'){
            try{
                decryptStr = JSON.parse(decryptStr);
            }catch(e){}
        }
        return decryptStr;
    }
    async _decryptByPlatfromKey(ciphertext:string,nonce:string,associatedData:string){
        const platformKey = await this.getPlatformCertificates() as CipherKey;
        const ciphertextBuffer = Buffer.from(ciphertext, 'base64');
        const authTag = ciphertextBuffer.slice(ciphertextBuffer.length - 16)
        const data = ciphertextBuffer.slice(0, ciphertextBuffer.length - 16)
        const decipherIv = Crypto.createDecipheriv('aes-256-gcm', platformKey, nonce)
        decipherIv.setAuthTag(Buffer.from(authTag))
        decipherIv.setAAD(Buffer.from(associatedData))
        const decryptStr = decipherIv.update(data, undefined, 'utf8')
        decipherIv.final();
        return decryptStr;
    }
}

module.exports = WechatMchSDK;