Resolve "Remove all use of GLOBALS"

Closes #13

classes/Endpoint.php

-<?php
+<?php declare(strict_types=1);
 
 namespace uib\ub\loadspeakr;
 
 
-class Endpoint
+use UnexpectedValueException;
+
+final class Endpoint
 {
-    private $sparqlUrl;
-    private $params;
+    private string $sparqlUrl;
+    private array $params;
 
-    public function __construct($sparqlUrl, array $params)
+    public function __construct(string $sparqlUrl, array $params)
     {
         $this->sparqlUrl = $sparqlUrl;
         $this->params = $params;
@@ -17,112 +19,117 @@ class Endpoint
     public function query($q, $output = 'json')
     {
         global $conf;
-        if (!empty($this->params['output'])) {
-            $auxoutput = $this->params['output'];
-        }
         $accept = 'application/sparql-results+json';
-        if ($output != null) {
-            $this->params['output'] = $output;
-        }
-        if ($output == 'xml') {
+        $modified = 0;
+        $aux = '';
+
+        if ($output === 'xml') {
             $accept = 'application/sparql-results+xml';
-        } elseif ($output == 'rdf') {
+        } elseif ($output === 'rdf') {
             $accept = 'application/rdf+xml';
         }
 
-        $modified = 0;
-        $now = time();
-        $cacheFile = "";
-        if (!empty($conf['cache']['global']) && is_int($conf['cache']['global']) && $conf['cache']['global'] > 0) {
-            $cacheFile = $conf['home'] . "cache/query" . md5($this->sparqlUrl . $q);
+        $cacheFile = $conf['home'] . "cache/query" . md5($this->sparqlUrl . $q);
+        if ($this->caching($conf)) {
             if (file_exists($cacheFile)) {
                 $modified = filemtime($cacheFile);
             }
-        }
-        if (is_int(
-            $conf['cache']['global']
-          ) && $conf['cache']['global'] > 0 && $modified + $conf['cache']['global'] > $now) {
-            if ($conf['debug']) {
-                $msg = "Taking data from cache ($cacheFile). Renewal in " . ($modified + $conf['cache']['global'] - $now) . " seconds\n";
-                Logging::log($msg);
-                echo $msg;
-            }
-            $aux = (file_get_contents($cacheFile));
-        } else {
-            $c = curl_init();
-            $context = array();
-            $context[0] = 'Connection: close';
-            $context[1] = 'Accept: ' . $accept;
-            $params = $this->params;
-            $params['query'] = $q;
-            $url = $this->sparqlUrl . '?' . http_build_query($params, '', '&');
-            curl_setopt($c, CURLOPT_URL, $url);
-            curl_setopt($c, CURLOPT_HTTPHEADER, $context);
-            curl_setopt($c, CURLOPT_USERAGENT, "LODSPeaKr version " . $conf['version']);
-            curl_setopt($c, CURLOPT_RETURNTRANSFER, true);
-            $aux = curl_exec($c); // execute the curl command
-            if ($conf['debug']) {
-                if ($aux == false) {
-                    Logging::log(
-                      "Error executing SPARQL query (" . $this->sparqlUrl . "): " . curl_error($c),
-                      E_USER_ERROR
-                    );
-                    echo("Error executing SPARQL query (" . $this->sparqlUrl . "): " . curl_error($c));
-                }
-            }
-            $http_status = intval(curl_getinfo($c, CURLINFO_HTTP_CODE));
-            curl_close($c);
-            if (!empty($auxoutput)) {
-                $this->params['output'] = $auxoutput;
-            }
-            if (is_int($conf['cache']['global']) && $conf['cache']['global'] > 0 && $http_status == 200) {
-                file_put_contents($cacheFile, ($aux), LOCK_EX);
-                if ($conf['debug']) {
-                    $msg = "Notice: Writing results in " . $cacheFile . "\n";
-                    Logging::log($msg, E_USER_NOTICE);
-                    echo($msg);
-                }
+
+            /**
+             * If we have cached content lets use it.
+             */
+            if ($modified + $conf['cache']['global'] > time()) {
+                $aux = file_get_contents($cacheFile);
             }
         }
-        if (preg_match("/select/i", $q)) {
-            $r = json_decode($aux, true);
-            if ($conf['debug']) {
-                if ($r == false) {
-                    Logging::log("Warning: Results from a SELECT sparql query couldn't get parsed", E_USER_WARNING);
-                    echo("Warning: Results from a SELECT sparql query couldn't get parsed");
-                }
-            }
-            return $r;
+
+        if (!$aux) {
+            $result = $this->curl($q, $accept, $conf);
+            $aux = $result['result'];
+            $this->updateCache($result['status'], $cacheFile, $aux, $conf);
         }
 
+        if (!$aux) {
+            return $aux;
+        }
+
+        return $this->result($q, $aux);
+    }
+
+    private function result(string $q, string $aux)
+    {
+        if (false !== stripos($q, "select")) {
+            return json_decode($aux, true);
+        }
 
-        if (preg_match("/describe/i", $q)) {
+        if (false !== stripos($q, "describe")) {
             return $aux;
         }
-        if (preg_match("/construct/i", $q)) {
+
+        if (false !== stripos($q, "construct")) {
             return $aux;
         }
-        if (preg_match("/ask/i", $q)) {
-            $r = json_decode($aux, true);
-            return $r;
+
+        if (false !== stripos($q, "ask")) {
+            return json_decode($aux, true);
         }
+
+        return $aux;
+    }
+
+    private function caching(array $conf): bool
+    {
+        return !empty($conf['cache']['global']) && is_int($conf['cache']['global']) && $conf['cache']['global'] > 0;
     }
 
-    public function queryPost($q)
+    private function updateCache($http_status, $cacheFile, $aux, $conf): void
     {
+        if ($http_status === 200 && $this->caching($conf)) {
+            $result = file_put_contents($cacheFile, ($aux), LOCK_EX);
+
+            if (!$result) {
+                throw new UnexpectedValueException(
+                  'Unable to update cache: ' . $cacheFile
+                );
+            }
+        }
+    }
+
+    private function curl(string $request, $accept, array $conf): array
+    {
+        $resource = curl_init();
+        $context = ['Connection: close', 'Accept: ' . $accept];
         $params = $this->params;
-        $params['query'] = $q;
-        $ch = curl_init();
-        curl_setopt($ch, CURLOPT_URL, $this->sparqlUrl);
-        curl_setopt($ch, CURLOPT_POST, count($params));
-        curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($params));
-        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
-        //execute post
-        $result = curl_exec($ch);
-        return $result;
+        $params['query'] = $request;
+        $url = $this->sparqlUrl . '?' . http_build_query($params, '', '&');
+        curl_setopt($resource, CURLOPT_URL, $url);
+        curl_setopt($resource, CURLOPT_HTTPHEADER, $context);
+        curl_setopt($resource, CURLOPT_USERAGENT, "LODSPeaKr version " . $conf['version']);
+        curl_setopt($resource, CURLOPT_RETURNTRANSFER, true);
+        $result = curl_exec($resource);
+        $http_status = (int)curl_getinfo($resource, CURLINFO_HTTP_CODE);
+        curl_close($resource);
+
+        return [
+            'result' => $result,
+            'status' => $http_status,
+        ];
+    }
+
+    public function queryPost(string $request)
+    {
+        $params = $this->params;
+        $params['query'] = $request;
+        $resource = curl_init();
+        curl_setopt($resource, CURLOPT_URL, $this->sparqlUrl);
+        curl_setopt($resource, CURLOPT_POST, count($params));
+        curl_setopt($resource, CURLOPT_POSTFIELDS, http_build_query($params));
+        curl_setopt($resource, CURLOPT_RETURNTRANSFER, 1);
+
+        return curl_exec($resource);
     }
 
-    public function getSparqlURL()
+    public function getSparqlURL(): string
     {
         return $this->sparqlUrl;
     }