Load feature flags also from DB

[MAILPOET-2008]

lib/Features/FeaturesController.php

@@ -2,6 +2,8 @@
 
 namespace MailPoet\Features;
 
+use MailPoet\Models\FeatureFlag;
+
 class FeaturesController {
 
   // Define features below in the following form:
@@ -12,11 +14,42 @@ class FeaturesController {
   public static $defaults = [
   ];
 
+  /** @var array */
+  private $flags;
+
   /** @return bool */
   function isSupported($feature) {
-    if (!array_key_exists($feature, self::$defaults)) {
+    $this->ensureFlagsLoaded();
+    if (!array_key_exists($feature, $this->flags)) {
       throw new \RuntimeException("Unknown feature '$feature'");
     }
-    return self::$defaults[$feature];
+    return $this->flags[$feature];
+  }
+
+  /** @return array */
+  function getAllFlags() {
+    $this->ensureFlagsLoaded();
+    return $this->flags;
+  }
+
+  private function ensureFlagsLoaded() {
+    if ($this->flags !== null) {
+      return;
+    }
+
+    $this->flags = [];
+    $flagsMap = $this->getValueMap();
+    foreach (self::$defaults as $name => $default) {
+      $this->flags[$name] = isset($flagsMap[$name]) ? $flagsMap[$name] : $default;
+    }
+  }
+
+  private function getValueMap() {
+    $features = FeatureFlag::selectMany(['name', 'value'])->findMany();
+    $featuresMap = [];
+    foreach ($features as $feature) {
+      $featuresMap[$feature->name] = (bool)$feature->value;
+    }
+    return $featuresMap;
   }
 }