# Install  
`npm install qiwi-shop`  

# About  
Qiwi shop rest api module (qiwi.com)  

# Example  
## Dependencies

```js
const QiwiShop = require("qiwi-shop");
const express = require("express");
const bodyParser = require("body-parser");
const app = express();

app.use(bodyParser.json());
```

## Creation of bills

```js
const projectId = "0000001"; // shop id
const apiId = "000000001"; // api id
const apiPassword = "api"; // api password
const notificationPassword = "notification"; // notification password

const inFiveDays = new Date().getTime() + 1000 * 60 * 60 * 24 * 5;
const qiwi = new QiwiShop(projectId, apiId, apiPassword, notificationPassword);

// this action is optional
qiwi.beforeCreateBill = function (billId, data) {
  // you can save some information to db before the request e.t.c.
  // you can return a promise
}

app.post('/payments/bill/create/', (req, res, next) => {    
  qiwi.createBill({
    user: 'tel:+7910100100',
    amount: '10',
    ccy: 'RUB', 
    comment: 'recharge',
    lifetime: new Date(inFiveDays).toISOString(),
    pay_source: 'qw',
    prv_name: 'example.com' 
  }).then((result) => {
    if(!result || !result.response || result.response.result_code != 0) {
        throw new Error('Qiwi bill creation fail');
    }
    
    // redirect to payment (optional)
    res.redirect(qiwi.getPaymentUrl({ 
      shop: qiwi.projectId, 
      transaction: result.response.bill.bill_id 
    }));
  });
});
```

## Handling a notification

```js
// notification handler 
const successHandler = (data, callback) => {
    // data === req.body    
    // save payment info or something else to db e.t.c    
    // callback() or return promise
};

const errorHandler = (err, meta) => {
    // you can save something to a file, db e.t.c.
    // the operation must be synchronous or in the background 
};

let authenticationBySignature = false; // false == basic authentication

app.post('payments/notification/', qiwi.notify(successHandler, errorHandler, authenticationBySignature));
```

# Description  
You can write a custom notification handler, but the library version includes a data/authentication validation and automatically send all headers in the necessary format

# API  
### .constructor(projectId, apiId, apiPassword, notificationPassword)  
you can find all arguments in your qiwi shop account  

### .getPaymentUrl([query])  
returns qiwi bill creation url

### .beforeCreateBill(billId, data)  
will be called before the bill creation request, but after the hash creation

### .createBill(data)  
returns promise, create a bill, data options must comply with documentation  
.user and .amount is required

### .getBillStatus(billId)  
returns a promise, get a bill status

### .cancelBill(billId)  
returns a promise, cancel a bill

### .refundBill(billId, data)  
returns a promise, refunds a bill,  data options must comply with documentation

### .getRefundStatus(billId, refundId)  
returns a promise, gets a bill refund status

### .checkNotificationAuthBasic(req)  
checks a notification by a basic authentication

### .checkNotificationAuthSignature(req)  
checks a notification by a signature

### .createXml(code)  
creates xml string for the response

### .notify(fn, onError, [checkSignature])  
qiwi notification handler, it is "connect" middleware