docs(readme): Update readme

Author: unicodeveloper

README.md

@@ -36,14 +36,172 @@ Also, register the Facade like so:
 
 ## Configuration
 
-To get started, you'll need to publish all vendor assets:
+You can publish the configuration file using this command:
 
 ```bash
-$ php artisan vendor:publish --provider="Unicodeveloper\Paystack\PaystackServiceProvider"
+php artisan config:publish unicodeveloper/laravel-paystack
 ```
 
+A configuration-file named `paystack.php` with some sensible defaults will be placed in your `config` directory:
+
+```php
+<?php
+
+return [
+
+    /**
+     * Public Key From Paystack Dashboard
+     *
+     */
+    'publicKey' => getenv('PAYSTACK_PUBLIC_KEY'),
+
+    /**
+     * Secret Key From Paystack Dashboard
+     *
+     */
+    'secretKey' => getenv('PAYSTACK_SECRET_KEY'),
+
+    /**
+     * Paystack Payment URL
+     *
+     */
+    'paymentUrl' => getenv('PAYSTACK_PAYMENT_URL'),
+
+    /**
+     * Optional email address of the merchant
+     *
+     */
+    'merchantEmail' => getenv('MERCHANT_EMAIL'),
+
+    /**
+     * Unique transaction reference
+     */
+    'reference' => 'payref'.time().'tranx',
+];
+```
+
+
+##General payment flow
+
+Though there are multiple ways to pay an order, most payment gateways except you to follow the following flow in your checkout process:
+
+###1. The customer is redirected to the payment provider
+After the customer has gone through the checkout process and is ready to pay, the customer must be redirected to site of the payment provider.
+
+The redirection is accomplished by submitting a form with some hidden fields. The form must post to the site of the payment provider. The hidden fields minimally specify the amount that must be paid, the order id and a hash.
+
+The hash is calculated using the hidden form fields and a non-public secret. The hash used by the payment provider to verify if the request is valid.
+
+
+###2. The customer pays on the site of the payment provider
+The customer arrived on the site of the payment provider and gets to choose a payment method. All steps necessary to pay the order are taken care of by the payment provider.
+
+###3. The customer gets redirected back
+After having paid the order the customer is redirected back. In the redirection request to the shop-site some values are returned. The values are usually the order id, a paymentresult and a hash.
+
+The hash is calculated out of some of the fields returned and a secret non-public value. This hash is used to verify if the request is valid and comes from the payment provider. It is paramount that this hash is thoroughly checked.
+
+The payment result can be something like "payment ok", "customer cancelled payment" or "payment declined".
+
+
 ## Usage
 
+1. Open your .env file and add your public key, secret key, merchant email and payment url like so:
+
+```php
+PAYSTACK_PUBLIC_KEY=xxxxxxxxxxxxx
+PAYSTACK_SECRET_KEY=xxxxxxxxxxxxx
+PAYSTACK_PAYMENT_URL=https://api.paystack.co
+[email protected]
+```
+
+2. Set up routes and controller methods like so:
+
+```php
+Route::post('/pay', 'PaymentController@redirectToGateway')->name('pay');
+Route::get('/payment/callback', 'PaymentController@handleGatewayCallback');
+```
+
+```php
+<?php
+
+namespace App\Http\Controllers;
+
+use Illuminate\Http\Request;
+
+use App\Http\Requests;
+use App\Http\Controllers\Controller;
+use Paystack;
+
+class PaymentController extends Controller
+{
+
+    /**
+     * Redirect the User to Paystack Payment Page
+     * @return Url
+     */
+    public function redirectToGateway()
+    {
+        return Paystack::getAuthorizationUrl()->redirectNow();
+    }
+
+    /**
+     * Obtain Paystack payment information
+     * @return [type] [description]
+     */
+    public function handleGatewayCallback()
+    {
+        $paymentDetails = Paystack::getPaymentData();
+
+        dd($paymentDetails); // Now you have the payment details,
+        // you can store the authorisation code in your db to allow for recurrent subscriptions
+        // you can then redirect or do whatever you want
+    }
+}
+```
+
+3. A sample form will look like so:
+
+```html
+<form method="POST" action="{{ route('pay') }}" accept-charset="UTF-8" class="form-horizontal" role="form">
+        <div class="row" style="margin-bottom:40px;">
+          <div class="col-md-8 col-md-offset-2">
+            <p>
+                <div>
+                    Lagos Eyo Print Tee Shirt
+                    ₦ 2,950
+                </div>
+            </p>
+            <input type="hidden" name="email" value="[email protected]"> {{-- required --}}
+            <input type="hidden" name="orderID" value="345">
+            <input type="hidden" name="amount" value="800"> {{-- required --}}
+            <input type="hidden" name="quantity" value="3">
+            <input type="hidden" name="reference" value="{{ config('paystack.reference') }}"> {{-- required --}}
+            <input type="hidden" name="key" value="{{ config('paystack.secretKey') }}"> {{-- required --}}
+            {{ csrf_field() }}
+
+            <p>
+              <button class="btn btn-success btn-lg btn-block" type="submit" value="Pay Now!">
+              <i class="fa fa-plus-circle fa-lg"></i> Pay Now!
+              </button>
+            </p>
+          </div>
+        </div>
+</form>
+```
+
+When clicking the submit button the customer gets redirected to the Paystack site.
+
+So now we've redirected the customer to Paystack. The customer did some actions there (hopefully he or she paid the order) and now gets redirected back to our shop site.
+
+Paystack will redirect the customer to the url of the route that is specified in the Callback URL of the Web Hooks section on Paystack dashboard.
+
+We must validate if the redirect to our site is a valid request (we don't want imposters to wrongfully place non-paid order).
+
+In the controller that handles the request coming from the payment provider, we have
+
+`Paystack::getPaymentData()` - This function calls the verification methods and ensure it is a valid transction else it throws an exception.
+
 ## Contributing
 
 Please feel free to fork this package and contribute by submitting a pull request to enhance the functionalities.

resources/config/paystack.php

@@ -29,5 +29,5 @@
     /**
      * Unique transaction reference
      */
-    'reference' => 'payref'.time().'tranx'
+    'reference' => 'payref'.time().'tranx',
 ];