[coopengo_modules/account_payment_paybox] account_payment_paybox: Add…

… README instructions (coopengo#6)

coopengo_modules/account_payment_paybox/README.md

@@ -1 +1,78 @@
-# trytond-account-payment-paybox
+# Account Payment Paybox Module
+
+This module provides a new journal process method to proceed account payments
+using the external and secured [paybox](http://www1.paybox.com/?lang=en) platform.
+You'll need the tryton 'account_payment' module installed and of course, a valid paybox account
+with your credentials and API references.
+This new module adds:
+
+- A new section into the tryton server configuration file. (For the API references)
+- The possibility to process payments using the paybox method.
+- A Payment URL on paybox payment groups to perform the transaction.
+- A NodeJS endpoint server to receive Paybox's digitally signed callbacks
+  which update as well the payments state into the tryton database.
+
+## The tryton server configuration
+First of all, you'll need to set this new section with your API references / credentials
+as following: (The API informations below are given by paybox to a sandbox/test account)
+
+```
+[paybox]
+payment_url = https://preprod-tpeweb.paybox.com/cgi/MYchoix_pagepaiement.cgi
+PBX_SITE = 1999888
+PBX_RANG = 43
+PBX_IDENTIFIANT = 107975626
+PBX_RETOUR=number:R;code:E;signature:K
+PBX_REPONDRE_A = https://3907fcba.ngrok.io
+secret=0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF
+```
+Once you have filled those variables with your data, the server must be restarted.
+
+## Deploy the NodeJS callback server
+All the sources are into the "callback" directory of the account_payment_paybox module
+
+### With docker
+
+build:
+```
+npm run docker
+```
+
+run: 
+```
+docker run -d
+-e PAYBOX_PORT=
+-e PAYBOX_TRYTON_URL=
+-e PAYBOX_TRYTON_DB=
+-e PAYBOX_TRYTON_USERNAME=
+-e PAYBOX_TRYTON_PASSWORD=
+coopengo/paybox
+```
+
+### As a node endpoint
+
+```
+cd callback
+node .
+```
+
+*NB: You may need to run npm i  before run node into the callback directory*
+
+## The Paybox Journal
+To create and process payments, you'll need to configure a new payment journal using "Paybox" as process method.
+
+
+## The paybox payment groups
+Once you've created some paybox payments, you can process them and create payment groups.
+
+All these payment groups have a unique URL which is valid for 15 minutes after it's generation. Passing this delay,
+you'll need to fail the payment and generate another one.
+
+You can click on the URL of the payment group form view to open up the browser straight on the paybox payment page.
+Type your credit card informations and, depending on the transaction state, paybox will call back our NodeJS server
+which will update the tryton payment state (If the certificate signature is valid otherwise, the request will be logged
+and through away).
+
+Nota: the payment group number is the paybox transaction reference, so you can go to the paybox backoffice with this number
+to retrieve the logs of the payment transaction.
+If an error occurs during the transaction, the code will be printed in the callback server logs. You can check from the [paybox documentation guide](http://www1.paybox.com/wp-content/uploads/2017/08/ManuelIntegrationVerifone_PayboxSystem_V8.0_EN.pdf) (Page 65) what does this code means.