times: Switch from Navitia to custom GTFS source

We can probably make an option to use either Navitia or GTFS since we
have the code for both anyway.

classes/Gtfs.php

@@ -0,0 +1,40 @@
+<?php
+
+class Gtfs {
+    private $endpoint;
+    private $secret;
+
+    public function __construct($endpoint, $secret) {
+        $this->endpoint = $endpoint;
+        $this->secret = $secret;
+    }
+
+    public function getStopSchedule($stopId) {
+        // TODO: Error handling
+
+        $ch = curl_init();
+        curl_setopt($ch, CURLOPT_URL,
+            $this->endpoint . '?stop=' . $stopId . '&agency=1');
+
+        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
+            'secret: ' . $this->secret
+        ));
+
+        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
+        $response = curl_exec($ch);
+        curl_close($ch);
+
+        // TODO: Error handling
+        $json = json_decode($response);
+
+        $tmp_dateTimes = $json;
+
+        $dateTime = array();
+        foreach($tmp_dateTimes as $tmp_dateTime) {
+            $dateTime[] = strtotime($tmp_dateTime);
+        }
+
+        return json_encode($dateTime);
+    }
+}
+

public/times.php

@@ -1,16 +1,17 @@
 <?php
 
-require_once('../classes/Navitia.php');
+require_once('../classes/Gtfs.php');
 
 $config = json_decode(file_get_contents('../config.json'));
 
-// Navitia creds
-$token = $config->navitia->token;
-$stopId = $config->navitia->stopId;
+// Gtfs configs
+$secret = $config->gtfs->secret;
+$endpoint = $config->gtfs->endpoint;
+$stopId = $config->gtfs->stopId;
 
-$navitia= new Navitia($token);
+$gtfs = new Gtfs($endpoint, $secret);
 
-$nextTrips = $navitia->getStopSchedule($stopId);
+$nextTrips = $gtfs->getStopSchedule($stopId);
 
 header('Content-Type: application/json');