added the currency conversion endpoint

README.md

@@ -134,6 +134,31 @@ catch (ResponseException $e) {
 }
 ```
 
+## Convert Endpoint
+Accessing the currency conversion endpoint may be done like so:
+
+```php
+use Fadion\Fixerio\Currency; //optional if you want to use currency constants
+use Fadion\Fixerio\Convert;
+
+$converter = new Convert();
+$converter->key('YOUR_ACCESS_KEY');
+$converter->from('USD');
+$converter->to('CAD');
+$converter->amount('22.50');
+$converter = new Convert('USD', 'CAD', '22.50');
+$result = $converter->get();
+print $result;
+
+```
+
+You may also use currency constants
+
+```php
+$converter->from(Currency::USD);
+```
+
+
 ## Laravel Usage
 
 Nothing changes for Laravel apart from the Facade. It's just a convenience for a tad shorter way of using the package:

src/Convert.php

@@ -0,0 +1,302 @@
+<?php
+
+namespace Fadion\Fixerio;
+
+use DateTime;
+use Fadion\Fixerio\Exceptions\ConnectionException;
+use Fadion\Fixerio\Exceptions\ResponseException;
+use GuzzleHttp\Client as GuzzleClient;
+use GuzzleHttp\Exception\TransferException;
+
+class Convert
+{
+    /**
+     * Guzzle client
+     * @var GuzzleHttp\Client
+     */
+    private $guzzle;
+
+    /**
+     * URL of fixer.io
+     * @var string
+     */
+    private $url = "data.fixer.io/api";
+
+    /**
+     * Http or Https
+     * @var string
+     */
+    private $protocol = 'http';
+
+    /**
+     * Holds whether the response should be
+     * an object or not
+     * @var array
+     */
+    private $asObject = false;
+
+    /**
+     * Holds the Fixer.io API key
+     *
+     * @var null|string
+     */
+    private $key = null;
+
+
+    /**
+     * Holds the from currency
+     *
+     * @var null|string
+     */
+    private $from = null;
+
+    /**
+     * Holds the to currency
+     *
+     * @var null|string
+     */
+    private $to = null;
+
+    /**
+     * Holds the amount to convert
+     *
+     * @var null|string
+     */
+    private $amount = null;
+
+
+    /**
+     * @param $guzzle Guzzle client
+     */
+    public function __construct($guzzle = null)
+    {
+        if (isset($guzzle)) {
+            $this->guzzle = $guzzle;
+        } else {
+            $this->guzzle = new GuzzleClient();
+        }        
+    }
+
+    /**
+     * Sets the from currency
+     *
+     * @param  string $to
+     * @return Exchange
+     */
+    public function from($from)
+    {
+        $this->from = $from;
+
+        return $this;
+    }
+
+
+    /**
+     * Sets the to currency
+     *
+     * @param  string $to
+     * @return Exchange
+     */
+    public function to($to)
+    {
+        $this->to = $to;
+
+        return $this;
+    }
+
+
+    /**
+     * Sets the amount
+     *
+     * @param  string $to
+     * @return Exchange
+     */
+    public function amount($amount)
+    {
+        $this->amount = $amount;
+
+        return $this;
+    }
+
+    /**
+     * Sets the protocol to https
+     *
+     * @return Exchange
+     */
+    public function secure()
+    {
+        $this->protocol = 'https';
+
+        return $this;
+    }
+
+    /**
+     * Sets the API key
+     *
+     * @param  string $key
+     * @return Exchange
+     */
+    public function key($key)
+    {
+        $this->key = $key;
+
+        return $this;
+    }
+
+    /**
+     * Returns the correctly formatted url
+     *
+     * @return string
+     */
+    public function getUrl()
+    {
+        return $this->buildUrl($this->url);
+    }
+
+    /**
+     * Makes the request and returns the response
+     * with the rates.
+     *
+     * @throws ConnectionException if the request is incorrect or times out
+     * @throws ResponseException if the response is malformed
+     * @return array
+     */
+    public function get()
+    {
+        $url = $this->buildUrl($this->url);
+
+        try {
+            $response = $this->makeRequest($url);
+
+            return $this->prepareResponse($response);
+        }
+        // The client needs to know only one exception, no
+        // matter what exception is thrown by Guzzle
+         catch (TransferException $e) {
+            throw new ConnectionException($e->getMessage());
+        }
+    }
+
+    /**
+     * Makes the request and returns the response
+     * with the rates, as a Result object
+     *
+     * @throws ConnectionException if the request is incorrect or times out
+     * @throws ResponseException if the response is malformed
+     * @return Result
+     */
+    public function getResult()
+    {
+        $url = $this->buildUrl($this->url);
+
+        try {
+            $response = $this->makeRequest($url);
+
+            return $this->prepareResponseResult($response);
+        }
+        // The client needs to know only one exception, no
+        // matter what exception is thrown by Guzzle
+         catch (TransferException $e) {
+            throw new ConnectionException($e->getMessage());
+        }
+    }
+
+    /**
+     * Alias of get() but returns an object
+     * response.
+     *
+     * @throws ConnectionException if the request is incorrect or times out
+     * @throws ResponseException if the response is malformed
+     * @return object
+     */
+    public function getAsObject()
+    {
+        $this->asObject = true;
+
+        return $this->get();
+    }
+
+    /**
+     * Forms the correct url from the different parts
+     *
+     * @param  string $url
+     * @return string
+     */
+    private function buildUrl($url)
+    {
+        $url = $this->protocol . '://' . $url . '/convert';
+
+        if ($this->key) {
+            $url .= '?access_key=' . $this->key;
+        }
+
+        if ($this->from) {
+            $url .= '&from=' . $this->from;
+        }
+
+        if ($this->to) {
+            $url .= '&to=' . $this->to;
+        }
+
+        if ($this->amount) {
+            $url .= '&amount=' . $this->amount;
+        }
+
+        return $url;
+    }
+
+    /**
+     * Makes the http request
+     *
+     * @param  string $url
+     * @return string
+     */
+    private function makeRequest($url)
+    {
+        $response = $this->guzzle->request('GET', $url);
+
+        return $response->getBody();
+    }
+
+    /**
+     * @param  string $body
+     * @throws ResponseException if the response is malformed
+     * @return array
+     */
+    private function prepareResponse($body)
+    {
+        $response = json_decode($body, true);
+
+        if (isset($response['result'])) {
+            return ($this->asObject) ? (object) $response['result'] : $response['result'];
+        } else if (isset($response['error'])) {
+            throw new ResponseException($response['error']);
+            // var_dump($response);
+            // throw new ResponseException("{$response['error']['type']} {$response['error']['info']}");
+        } else {
+            throw new ResponseException('Response body is malformed.');
+        }
+    }
+
+    /**
+     * @param  string $body
+     * @throws ResponseException if the response is malformed
+     * @return Result
+     */
+    private function prepareResponseResult($body)
+    {
+        $response = json_decode($body, true);
+
+        if (isset($response['query']) and isset($response['result'])) {
+            return new Result(
+                $response['base'],
+                new DateTime($response['date']),
+                $response['rates']
+            );
+        } else if (isset($response['error'])) {
+            throw new ResponseException($response['error']);
+        } else {
+            throw new ResponseException('Response body is malformed.');
+        }
+    }
+}