diff --git a/lib/Service/RecipeService.php b/lib/Service/RecipeService.php
index 06efffda..b790bb0a 100644
--- a/lib/Service/RecipeService.php
+++ b/lib/Service/RecipeService.php
@@ -2,6 +2,9 @@
 
 namespace OCA\Cookbook\Service;
 
+use Exception;
+use OCP\Files\NotFoundException;
+use OCP\Files\NotPermittedException;
 use OCP\Image;
 use OCP\IConfig;
 use OCP\Files\IRootFolder;
@@ -9,16 +12,23 @@ use OCP\Files\FileInfo;
 use OCP\Files\File;
 use OCP\Files\Folder;
 use OCP\IDBConnection;
-
 use OCA\Cookbook\Db\RecipeDb;
+use OCP\PreConditionNotMetException;
 
-class RecipeService {
+/**
+ * Main service class for the cookbook app.
+ *
+ * @package OCA\Cookbook\Service
+ */
+class RecipeService
+{
     private $root;
     private $userId;
     private $db;
     private $config;
 
-    public function __construct($UserId, IRootFolder $root, RecipeDb $db, IConfig $config) {
+    public function __construct(string $UserId, IRootFolder $root, RecipeDb $db, IConfig $config)
+    {
         $this->userId = $UserId;
         $this->root = $root;
         $this->db = $db;
@@ -26,14 +36,19 @@ class RecipeService {
     }
 
     /**
+     * Get a recipe by its folder id.
+     *
      * @param int $id
      *
-     * @return array
+     * @return array|null
      */
-    public function getRecipeById($id) {
+    public function getRecipeById(int $id)
+    {
         $file = $this->getRecipeFileByFolderId($id);
 
-        if(!$file) { return null; }
+        if (!$file) {
+            return null;
+        }
 
         return $this->parseRecipeFile($file);
     }
@@ -43,20 +58,27 @@ class RecipeService {
      *
      * @param int $id
      *
-     * @return \OCP\Files\File
+     * @return File|null
      */
-    public function getRecipeFileByFolderId($id) {
-        $user_folder = $this->getFolderForUser();
-        $recipe_folder = $user_folder->getById($id);
+    public function getRecipeFileByFolderId(int $id)
+    {
+        $userFolder = $this->getFolderForUser();
+        $recipeFolder = $userFolder->getById($id);
 
-        if(count($recipe_folder) <= 0) { return null; }
+        if (count($recipeFolder) <= 0) {
+            return null;
+        }
 
-        $recipe_folder = $recipe_folder[0];
+        $recipeFolder = $recipeFolder[0];
 
-        if($recipe_folder instanceof Folder === false) { return null; }
+        if ($recipeFolder instanceof Folder === false) {
+            return null;
+        }
 
-        foreach($recipe_folder->getDirectoryListing() as $file) {
-            if($this->isRecipeFile($file)) { return $file; }
+        foreach ($recipeFolder->getDirectoryListing() as $file) {
+            if ($this->isRecipeFile($file)) {
+                return $file;
+            }
         }
 
         return null;
@@ -69,13 +91,14 @@ class RecipeService {
      * @param array $json
      * @param string $key
      */
-    private function validateDuration($json, $key) {
+    private function validateDuration($json, $key)
+    {
         // Make sure we have a string and valid DateInterval
         // regex validation from here: https://stackoverflow.com/a/32045167
         $interval_regex = "/^P(?!$)(\d+Y)?(\d+M)?(\d+W)?(\d+D)?(T(?=\d)(\d+H)?(\d+M)?(\d+S)?)?$/";
-        if(isset($json[$key]) && is_string($json[$key])) {
+        if (isset($json[$key]) && is_string($json[$key])) {
             $time_string = $this->cleanUpString($json[$key]);
-            if(preg_match_all($interval_regex, $time_string)) {
+            if (preg_match_all($interval_regex, $time_string)) {
                 $json[$key] = $time_string;
             } else {
                 $json[$key] = "";
@@ -92,9 +115,14 @@ class RecipeService {
      *
      * @return array
      */
-    public function checkRecipe($json) {
-        if(!$json) { throw new \Exception('Recipe array was null'); }
-        if(!isset($json['name']) || !$json['name']) { throw new \Exception('Field "name" is required'); }
+    public function checkRecipe($json)
+    {
+        if (!$json) {
+            throw new Exception('Recipe array was null');
+        }
+        if (!isset($json['name']) || !$json['name']) {
+            throw new Exception('Field "name" is required');
+        }
 
         // Make sure the schema.org fields are present
         $json['@context'] = 'http://schema.org';
@@ -104,19 +132,19 @@ class RecipeService {
         $json['name'] = $this->cleanUpString($json['name']);
 
         // Make sure that "image" is a string of the highest resolution image available
-        if(isset($json['image']) && $json['image']) {
-            if(is_array($json['image'])) {
+        if (isset($json['image']) && $json['image']) {
+            if (is_array($json['image'])) {
                 // Get the image from a subproperty "url"
-                if(isset($json['image']['url'])) {
+                if (isset($json['image']['url'])) {
                     $json['image'] = $json['image']['url'];
 
-                // Try to get the image with the highest resolution by adding together all numbers in the url
+                    // Try to get the image with the highest resolution by adding together all numbers in the url
                 } else {
                     $images = $json['image'];
                     $image_size = 0;
 
-                    foreach($images as $img) {
-                        if(is_array($img) && isset($img['url'])) {
+                    foreach ($images as $img) {
+                        if (is_array($img) && isset($img['url'])) {
                             $img = $img['url'];
                         }
 
@@ -126,16 +154,16 @@ class RecipeService {
 
                         $this_image_size = 0;
 
-                        foreach($image_matches as $image_match) {
-                            $this_image_size += (int) $image_match; 
+                        foreach ($image_matches as $image_match) {
+                            $this_image_size += (int)$image_match;
                         }
 
-                        if($image_size === 0 || $this_image_size > $image_size) {
+                        if ($image_size === 0 || $this_image_size > $image_size) {
                             $json['image'] = $img;
                         }
                     }
                 }
-            } else if(!is_string($json['image'])) {
+            } else if (!is_string($json['image'])) {
                 $json['image'] = '';
             }
         } else {
@@ -146,11 +174,11 @@ class RecipeService {
         $json['image'] = stripslashes($json['image']);
 
         // Make sure that "recipeYield" is an integer which is at least 1 
-        if(isset($json['recipeYield']) && $json['recipeYield']) {
+        if (isset($json['recipeYield']) && $json['recipeYield']) {
             $yield = filter_var($json['recipeYield'], FILTER_SANITIZE_NUMBER_INT);
 
-            if($yield && $yield > 0) {
-                $json['recipeYield'] = (int) $yield;
+            if ($yield && $yield > 0) {
+                $json['recipeYield'] = (int)$yield;
             } else {
                 $json['recipeYield'] = 1;
             }
@@ -159,7 +187,7 @@ class RecipeService {
         }
 
         // Make sure that "keywords" is an array of unique strings
-        if(isset($json['keywords']) && is_string($json['keywords'])) {
+        if (isset($json['keywords']) && is_string($json['keywords'])) {
             $keywords = trim($json['keywords']);
             $keywords = trim($keywords, ',');
             $keywords = trim($keywords);
@@ -176,13 +204,15 @@ class RecipeService {
         }
 
         // Make sure that "recipeIngredient" is an array of strings
-        if(isset($json['recipeIngredient']) && is_array($json['recipeIngredient'])) {
+        if (isset($json['recipeIngredient']) && is_array($json['recipeIngredient'])) {
             $ingredients = [];
 
-            foreach($json['recipeIngredient'] as $i => $ingredient) {
+            foreach ($json['recipeIngredient'] as $i => $ingredient) {
                 $ingredient = $this->cleanUpString($ingredient);
 
-                if(!$ingredient) { continue; }
+                if (!$ingredient) {
+                    continue;
+                }
 
                 array_push($ingredients, $ingredient);
             }
@@ -193,37 +223,41 @@ class RecipeService {
         $json['recipeIngredient'] = array_filter($json['recipeIngredient']);
 
         // Make sure that "recipeInstructions" is an array of strings
-        if(isset($json['recipeInstructions'])) {
-            if(is_array($json['recipeInstructions'])) {
-                foreach($json['recipeInstructions'] as $i => $step) {
-                    if(is_string($step)) {
+        if (isset($json['recipeInstructions'])) {
+            if (is_array($json['recipeInstructions'])) {
+                foreach ($json['recipeInstructions'] as $i => $step) {
+                    if (is_string($step)) {
                         $json['recipeInstructions'][$i] = $this->cleanUpString($step, true);
-                    } else if(is_array($step) && isset($step['text'])) {
+                    } else if (is_array($step) && isset($step['text'])) {
                         $json['recipeInstructions'][$i] = $this->cleanUpString($step['text'], true);
                     } else {
                         $json['recipeInstructions'][$i] = '';
                     }
                 }
 
-            } else if(is_string($json['recipeInstructions'])) {
+            } else if (is_string($json['recipeInstructions'])) {
                 $json['recipeInstructions'] = html_entity_decode($json['recipeInstructions']);
 
                 $regex_matches = [];
-                preg_match_all('/<(p|li)>(.*?)<\/(p|li)>/', $json['recipeInstructions'], $regex_matches, PREG_SET_ORDER); 
+                preg_match_all('/<(p|li)>(.*?)<\/(p|li)>/', $json['recipeInstructions'], $regex_matches, PREG_SET_ORDER);
 
                 $instructions = [];
 
-                foreach($regex_matches as $regex_match) {
-                    if(!$regex_match || !isset($regex_match[2])) { continue; }
+                foreach ($regex_matches as $regex_match) {
+                    if (!$regex_match || !isset($regex_match[2])) {
+                        continue;
+                    }
 
                     $step = $this->cleanUpString($regex_match[2]);
 
-                    if(!$step) { continue; }
+                    if (!$step) {
+                        continue;
+                    }
 
                     array_push($instructions, $step);
                 }
 
-                if(sizeof($instructions) > 0) {
+                if (sizeof($instructions) > 0) {
                     $json['recipeInstructions'] = $instructions;
                 } else {
                     $json['recipeInstructions'] = explode(PHP_EOL, $json['recipeInstructions']);
@@ -232,22 +266,22 @@ class RecipeService {
                 $json['recipeInstructions'] = [];
             }
         } else {
-            $json['recipeInstructions'] = []; 
+            $json['recipeInstructions'] = [];
         }
 
-        $json['recipeInstructions'] = array_filter($json['recipeInstructions'], function($v) {
+        $json['recipeInstructions'] = array_filter($json['recipeInstructions'], function ($v) {
             return !empty($v) && $v !== "\n" && $v !== "\r";
         });
 
-      	// Make sure the 'description' is a string
-      	if(isset($json['description']) && is_string($json['description'])) {
-      		$json['description'] = $this->cleanUpString($json['description']);
-      	} else {
-      		$json['description'] = "";
-      	}
+        // Make sure the 'description' is a string
+        if (isset($json['description']) && is_string($json['description'])) {
+            $json['description'] = $this->cleanUpString($json['description']);
+        } else {
+            $json['description'] = "";
+        }
 
-      	// Make sure the 'url' is a URL, or blank
-        if(isset($json['url']) && $json['url']) {
+        // Make sure the 'url' is a URL, or blank
+        if (isset($json['url']) && $json['url']) {
             $url = filter_var($json['url'], FILTER_SANITIZE_URL);
             if (filter_var($url, FILTER_VALIDATE_URL) == false) {
                 $url = "";
@@ -267,36 +301,47 @@ class RecipeService {
     /**
      * @param string $html
      *
-     * @return array 
+     * @return array
      */
-    private function parseRecipeHtml($html) {
-        if(!$html) { return null; }
+    private function parseRecipeHtml($html)
+    {
+        if (!$html) {
+            return null;
+        }
 
         //$html = str_replace(["\r", "\n", "\t"], '', $html);
         $json_matches = [];
 
         // Parse JSON
         preg_match_all('/<script type=["|\']application\/ld\+json["|\'][^>]*>([\s\S]*?)<\/script>/', $html, $json_matches, PREG_SET_ORDER);
-        foreach($json_matches as $json_match) {
-            if(!$json_match || !isset($json_match[1])) { continue; }
+        foreach ($json_matches as $json_match) {
+            if (!$json_match || !isset($json_match[1])) {
+                continue;
+            }
 
             $string = $json_match[1];
 
-            if(!$string) { continue; }
+            if (!$string) {
+                continue;
+            }
 
             $json = json_decode($string, true);
 
             // Look through @graph field for recipe
-            if($json && isset($json['@graph']) && is_array($json['@graph'])) {
-                foreach($json['@graph'] as $graph_item) {
-                    if(!isset($graph_item['@type']) || $graph_item['@type'] !== 'Recipe') { continue; }
+            if ($json && isset($json['@graph']) && is_array($json['@graph'])) {
+                foreach ($json['@graph'] as $graph_item) {
+                    if (!isset($graph_item['@type']) || $graph_item['@type'] !== 'Recipe') {
+                        continue;
+                    }
 
                     $json = $graph_item;
-                    break;        
+                    break;
                 }
             }
 
-            if(!$json || !isset($json['@type']) || $json['@type'] !== 'Recipe') { continue; }
+            if (!$json || !isset($json['@type']) || $json['@type'] !== 'Recipe') {
+                continue;
+            }
 
             return $this->checkRecipe($json);
         }
@@ -306,8 +351,8 @@ class RecipeService {
         $article_matches = [];
         preg_match_all('/<article.*itemtype=".*Recipe".*>([\s\S]*?)<\/article>/', $html, $article_matches);
 
-        if(!isset($article_matches[1][0])) {
-            throw new \Exception('Could not find article element');
+        if (!isset($article_matches[1][0])) {
+            throw new Exception('Could not find article element');
         }
 
         $article_html = $article_matches[1][0];
@@ -323,78 +368,100 @@ class RecipeService {
 
         $prop_matches = [];
 
-        foreach($props as $prop) {
+        foreach ($props as $prop) {
             preg_match_all('/itemprop="' . $prop . '".*>(.*?)<\//', $article_html, $prop_matches, PREG_SET_ORDER);
 
-            foreach($prop_matches as $prop_match) {
-                if(!$prop_match || !isset($prop_match[1])) { continue; }
+            foreach ($prop_matches as $prop_match) {
+                if (!$prop_match || !isset($prop_match[1])) {
+                    continue;
+                }
 
                 $value = $prop_match[1];
 
-                switch($prop) {
-                case 'image': case 'images': case 'thumbnail':
-                    $prop = 'image';
-                    $src_matches = [];
-                    preg_match('/="http([^"]+)"/', $prop_match[0], $src_matches);
+                switch ($prop) {
+                    case 'image':
+                    case 'images':
+                    case 'thumbnail':
+                        $prop = 'image';
+                        $src_matches = [];
+                        preg_match('/="http([^"]+)"/', $prop_match[0], $src_matches);
 
-                    if(!isset($src_matches[1])) { break; } 
+                        if (!isset($src_matches[1])) {
+                            break;
+                        }
 
-                    $src = 'http' . $src_matches[1];
+                        $src = 'http' . $src_matches[1];
 
-                    if(isset($json[$prop]) && strlen($json[$prop]) < strlen($src)) { break; }
+                        if (isset($json[$prop]) && strlen($json[$prop]) < strlen($src)) {
+                            break;
+                        }
 
-                    $json[$prop] = $src;
-                    break;
+                        $json[$prop] = $src;
+                        break;
 
-                case 'recipeIngredient': case 'ingredients':
-                    $prop = 'recipeIngredient';
-                    if(!$json[$prop]) { $json[$prop] = []; }
+                    case 'recipeIngredient':
+                    case 'ingredients':
+                        $prop = 'recipeIngredient';
+                        if (!$json[$prop]) {
+                            $json[$prop] = [];
+                        }
 
-                    array_push($json[$prop], $value);
-                    break;
+                        array_push($json[$prop], $value);
+                        break;
 
-                case 'recipeInstructions': case 'instructions': case 'steps': case 'guide':
-                    $prop = 'recipeInstructions';
-                    if(!$json[$prop]) { $json[$prop] = []; }
+                    case 'recipeInstructions':
+                    case 'instructions':
+                    case 'steps':
+                    case 'guide':
+                        $prop = 'recipeInstructions';
+                        if (!$json[$prop]) {
+                            $json[$prop] = [];
+                        }
 
-                    array_push($json[$prop], $value);
-                    break;
+                        array_push($json[$prop], $value);
+                        break;
 
-                default:
-                    if(isset($json[$prop]) && $json[$prop]) { break; }
+                    default:
+                        if (isset($json[$prop]) && $json[$prop]) {
+                            break;
+                        }
 
-                    $json[$prop] = $value;
+                        $json[$prop] = $value;
                 }
             }
         }
 
         // Make one final desparate attempt at getting the instructions
-        if(!isset($json['recipeInstructions']) || !$json['recipeInstructions'] || sizeof($json['recipeInstructions']) < 1) {
+        if (!isset($json['recipeInstructions']) || !$json['recipeInstructions'] || sizeof($json['recipeInstructions']) < 1) {
             $step_matches = [];
             $json['recipeInstructions'] = [];
             preg_match_all('/<p.*>(.*?)<\/p>/', $article_html, $step_matches, PREG_SET_ORDER);
 
-            foreach($step_matches as $step_match) {
-                if(!$step_match || !isset($step_match[1])) { continue; }
+            foreach ($step_matches as $step_match) {
+                if (!$step_match || !isset($step_match[1])) {
+                    continue;
+                }
 
                 $value = $step_match[1];
 
-                array_push($json['recipeInstructions'], $value); 
+                array_push($json['recipeInstructions'], $value);
             }
         }
 
         // If no keywords were found, use the ingredients
-        if(!isset($json['keywords']) || !$json['keywords']) {
+        if (!isset($json['keywords']) || !$json['keywords']) {
             $json['keywords'] = '';
 
-            if(isset($json['recipeIngredient'])) {
-                foreach($json['recipeIngredient'] as $ingredient) {
+            if (isset($json['recipeIngredient'])) {
+                foreach ($json['recipeIngredient'] as $ingredient) {
                     $keyword = strip_tags($ingredient);
                     $keyword = strtolower($keyword);
                     $parts = array_filter(explode(' ', $keyword));
                     $keyword = array_pop($parts);
 
-                    if($json['keywords']) { $json['keywords'] .= ','; }
+                    if ($json['keywords']) {
+                        $json['keywords'] .= ',';
+                    }
 
                     $json['keywords'] .= $keyword;
                 }
@@ -407,11 +474,12 @@ class RecipeService {
     /**
      * @param int $id
      */
-    public function deleteRecipe(int $id) {
+    public function deleteRecipe(int $id)
+    {
         $user_folder = $this->getFolderForUser();
         $recipe_folder = $user_folder->getById($id);
 
-        if($recipe_folder && sizeof($recipe_folder) > 0) {
+        if ($recipe_folder && sizeof($recipe_folder) > 0) {
             $recipe_folder[0]->delete();
         }
 
@@ -421,10 +489,13 @@ class RecipeService {
     /**
      * @param array $json
      *
-     * @return \OCP\Files\File
+     * @return File
      */
-    public function addRecipe($json) {
-        if(!$json || !isset($json['name']) || !$json['name']) { throw new \Exception('Recipe name not found'); }
+    public function addRecipe($json)
+    {
+        if (!$json || !isset($json['name']) || !$json['name']) {
+            throw new Exception('Recipe name not found');
+        }
 
         // Sanity check
         $json = $this->checkRecipe($json);
@@ -435,13 +506,13 @@ class RecipeService {
         $recipe_file = null;
 
         try {
-            if(isset($json['id']) && $json['id']) {
+            if (isset($json['id']) && $json['id']) {
                 $recipe_folder = $user_folder->getById($json['id'])[0];
 
                 $old_path = $recipe_folder->getPath();
-                $new_path = dirname($old_path) . '/' . $json['name'];   
+                $new_path = dirname($old_path) . '/' . $json['name'];
 
-                if($old_path !== $new_path) {
+                if ($old_path !== $new_path) {
                     $recipe_folder->move($new_path);
                 }
 
@@ -449,13 +520,13 @@ class RecipeService {
                 $recipe_folder = $user_folder->get($json['name']);
             }
 
-        } catch(\OCP\Files\NotFoundException $e) {
+        } catch (NotFoundException $e) {
             $recipe_folder = $user_folder->newFolder($json['name']);
         }
-        
+
         $recipe_file = $this->getRecipeFileByFolderId($recipe_folder->getId());
 
-        if(!$recipe_file) {
+        if (!$recipe_file) {
             $recipe_file = $recipe_folder->newFile($json['name'] . '.json');
         }
 
@@ -466,9 +537,9 @@ class RecipeService {
 
         // Download image and generate thumbnail
         $full_image_data = null;
-        
-        if(isset($json['image']) && $json['image']) {
-            if(strpos($json['image'], 'http') === 0) {
+
+        if (isset($json['image']) && $json['image']) {
+            if (strpos($json['image'], 'http') === 0) {
                 $json['image'] = str_replace(' ', '%20', $json['image']);
                 $full_image_data = file_get_contents($json['image']);
             } else {
@@ -478,14 +549,14 @@ class RecipeService {
         }
 
         // If image data was fetched, write it to disk
-        if($full_image_data) {
+        if ($full_image_data) {
             // Write the full image
             try {
                 $full_image_file = $recipe_folder->get('full.jpg');
-            } catch(\OCP\Files\NotFoundException $e) {
+            } catch (NotFoundException $e) {
                 $full_image_file = $recipe_folder->newFile('full.jpg');
             }
-            
+
             $full_image_file->putContent($full_image_data);
 
             // Write the thumbnail
@@ -493,13 +564,13 @@ class RecipeService {
             $thumb_image->loadFromData($full_image_data);
             $thumb_image->resize(128);
             $thumb_image->centerCrop();
-            
+
             try {
                 $thumb_image_file = $recipe_folder->get('thumb.jpg');
-            } catch(\OCP\Files\NotFoundException $e) {
+            } catch (NotFoundException $e) {
                 $thumb_image_file = $recipe_folder->newFile('thumb.jpg');
             }
-            
+
             $thumb_image_file->putContent($thumb_image->data());
         }
 
@@ -509,28 +580,35 @@ class RecipeService {
     /**
      * @param string $url
      *
-     * @return \OCP\Files\File
+     * @return File
      */
-    public function downloadRecipe($url) {
+    public function downloadRecipe($url)
+    {
         $host = parse_url($url);
 
-        if(!$host) { throw new \Exception('Could not parse URL'); }
+        if (!$host) {
+            throw new Exception('Could not parse URL');
+        }
 
         $opts = [
-    		"http" => [
-        		"method" => "GET",
-        		"header" => "User-Agent: Nextcloud Cookbook App"
-    		]
-		];
-		$context = stream_context_create($opts);
+            "http" => [
+                "method" => "GET",
+                "header" => "User-Agent: Nextcloud Cookbook App"
+            ]
+        ];
+        $context = stream_context_create($opts);
 
         $html = file_get_contents($url, false, $context);
 
-        if(!$html) { throw new \Exception('Could not fetch site ' . $url); }
+        if (!$html) {
+            throw new Exception('Could not fetch site ' . $url);
+        }
 
-        $json = $this->parseRecipeHtml($html); 
+        $json = $this->parseRecipeHtml($html);
 
-        if(!$json) { throw new \Exception('No recipe data found'); }
+        if (!$json) {
+            throw new Exception('No recipe data found');
+        }
 
         $json['url'] = $url;
 
@@ -540,16 +618,19 @@ class RecipeService {
     /**
      * @return array
      */
-    public function getRecipeFiles() {
+    public function getRecipeFiles()
+    {
         $user_folder = $this->getFolderForUser();
         $recipe_folders = $user_folder->getDirectoryListing();
         $recipe_files = [];
 
-        foreach($recipe_folders as $recipe_folder) {
+        foreach ($recipe_folders as $recipe_folder) {
             $recipe_file = $this->getRecipeFileByFolderId($recipe_folder->getId());
-            
-            if(!$recipe_file) { continue; }
-            
+
+            if (!$recipe_file) {
+                continue;
+            }
+
             $recipe_files[] = $recipe_file;
         }
 
@@ -559,7 +640,8 @@ class RecipeService {
     /**
      * Rebuilds the search index
      */
-    public function rebuildSearchIndex() {
+    public function rebuildSearchIndex()
+    {
         // Clear the database
         $this->db->emptySearchIndex($this->userId);
 
@@ -570,37 +652,38 @@ class RecipeService {
     /**
      * Updates the search index
      */
-    public function updateSearchIndex() {
+    public function updateSearchIndex()
+    {
         // Remove old cache folder if needed
         $legacy_cache_path = '/cookbook/cache';
 
-        if($this->root->nodeExists($legacy_cache_path)) {
+        if ($this->root->nodeExists($legacy_cache_path)) {
             $this->root->get($legacy_cache_path)->delete();
         }
 
         // Restructure files if needed
         $user_folder = $this->getFolderForUser();
 
-        foreach($user_folder->getDirectoryListing() as $node) {
+        foreach ($user_folder->getDirectoryListing() as $node) {
             // Move JSON files from the user directory into its own folder
-            if($this->isRecipeFile($node)) {
+            if ($this->isRecipeFile($node)) {
                 $recipe_name = str_replace('.json', '', $node->getName());
 
                 $node->move($node->getPath() . '_tmp');
-                
+
                 $recipe_folder = $user_folder->newFolder($recipe_name);
-                
+
                 $node->move($recipe_folder->getPath() . '/' . $recipe_name . '.json');
 
-            // Rename folders with .json extensions (this was likely caused by a migration bug)
-            } else if($node instanceof Folder && strpos($node->getName(), '.json')) {
+                // Rename folders with .json extensions (this was likely caused by a migration bug)
+            } else if ($node instanceof Folder && strpos($node->getName(), '.json')) {
                 $node->move(str_replace('.json', '', $node->getPath()));
-            
+
             }
         }
 
         // Re-index recipe files
-        foreach($this->getRecipeFiles() as $file) {
+        foreach ($this->getRecipeFiles() as $file) {
             $this->db->indexRecipeFile($file, $this->userId);
         }
 
@@ -611,11 +694,12 @@ class RecipeService {
     /**
      * Checks if a search index update is needed and performs it
      */
-    private function checkSearchIndexUpdate() {
+    private function checkSearchIndexUpdate()
+    {
         $last_index_update = $this->getSearchIndexLastUpdateTime();
         $interval = $this->getSearchIndexUpdateInterval();
 
-        if($last_index_update < 1 || time() > $last_index_update + ($interval * 60)) {
+        if ($last_index_update < 1 || time() > $last_index_update + ($interval * 60)) {
             $this->updateSearchIndex();
         }
     }
@@ -623,8 +707,9 @@ class RecipeService {
     /**
      * Gets the last time the search index was updated
      */
-    public function getSearchIndexLastUpdateTime() {
-        return (int) $this->config->getUserValue($this->userId, 'cookbook', 'last_index_update');
+    public function getSearchIndexLastUpdateTime()
+    {
+        return (int)$this->config->getUserValue($this->userId, 'cookbook', 'last_index_update');
     }
 
     /**
@@ -632,10 +717,11 @@ class RecipeService {
      *
      * @return array
      */
-    public function getAllKeywordsInSearchIndex() {
+    public function getAllKeywordsInSearchIndex()
+    {
         $this->checkSearchIndexUpdate();
 
-        return $this->db->findAllKeywords($this->userId); 
+        return $this->db->findAllKeywords($this->userId);
     }
 
     /**
@@ -643,10 +729,11 @@ class RecipeService {
      *
      * @return array
      */
-    public function getAllRecipesInSearchIndex() {
+    public function getAllRecipesInSearchIndex()
+    {
         $this->checkSearchIndexUpdate();
 
-        return $this->db->findAllRecipes($this->userId); 
+        return $this->db->findAllRecipes($this->userId);
     }
 
     /**
@@ -656,14 +743,15 @@ class RecipeService {
      *
      * @return array
      */
-    public function findRecipesInSearchIndex($keywords_string) {
+    public function findRecipesInSearchIndex($keywords_string)
+    {
         $this->checkSearchIndexUpdate();
 
         $keywords_string = strtolower($keywords_string);
         $keywords_array = [];
         preg_match_all('/[^ ,]+/', $keywords_string, $keywords_array);
 
-        if(sizeof($keywords_array) > 0) {
+        if (sizeof($keywords_array) > 0) {
             $keywords_array = $keywords_array[0];
         }
 
@@ -673,56 +761,70 @@ class RecipeService {
     /**
      * @param string $path
      */
-    public function setUserFolderPath(string $path) {
+    public function setUserFolderPath(string $path)
+    {
         $this->config->setUserValue($this->userId, 'cookbook', 'folder', $path);
     }
 
     /**
      * @return string
      */
-    public function getUserFolderPath() {
+    public function getUserFolderPath()
+    {
         $path = $this->config->getUserValue($this->userId, 'cookbook', 'folder');
 
-        if(!$path) { $path = '/Recipes'; }
+        if (!$path) {
+            $path = '/Recipes';
+        }
 
         return $path;
     }
-    
+
     /**
      * @param int $interval
+     * @throws PreConditionNotMetException
      */
-    public function setSearchIndexUpdateInterval(int $interval) {
+    public function setSearchIndexUpdateInterval(int $interval)
+    {
         $this->config->setUserValue($this->userId, 'cookbook', 'update_interval', $interval);
     }
-    
+
     /**
      * @return int
      */
-    public function getSearchIndexUpdateInterval() {
-        $interval = (int) $this->config->getUserValue($this->userId, 'cookbook', 'update_interval');
+    public function getSearchIndexUpdateInterval(): int
+    {
+        $interval = (int)$this->config->getUserValue($this->userId, 'cookbook', 'update_interval');
 
-        if($interval < 1) { $interval = 5; }
+        if ($interval < 1) {
+            $interval = 5;
+        }
 
         return $interval;
     }
 
     /**
-     * @return \OCP\Files\Folder
+     * @return Folder
      */
-    public function getFolderForUser() {
+    public function getFolderForUser()
+    {
         $path = '/' . $this->userId . '/files/' . $this->getUserFolderPath();
         $path = str_replace('//', '/', $path);
 
         return $this->getOrCreateFolder($path);
     }
-    
+
     /**
      * Finds a folder and creates it if non-existent
      * @param string $path path to the folder
      *
-     * @return \OCP\Files\Folder
+     * @return Folder
+     *
+     * @throws NotFoundException
+     * @throws NotPermittedException
      */
-    private function getOrCreateFolder($path) {
+    private function getOrCreateFolder($path)
+    {
         if ($this->root->nodeExists($path)) {
             $folder = $this->root->get($path);
         } else {
@@ -734,21 +836,26 @@ class RecipeService {
     /**
      * Get recipe file contents as an array
      *
-     * @param \OCP\Files\File $file
+     * @param File $file
      *
      * @return array
      */
-    public function parseRecipeFile($file) {
-        if(!$file) { return null; }
+    public function parseRecipeFile($file)
+    {
+        if (!$file) {
+            return null;
+        }
 
         $json = json_decode($file->getContent(), true);
 
-        if(!$json) { return null; }
+        if (!$json) {
+            return null;
+        }
 
         $json['id'] = $file->getParent()->getId();
 
         return $this->checkRecipe($json);
-    } 
+    }
 
     /**
      * Gets the image file for a recipe
@@ -756,18 +863,23 @@ class RecipeService {
      * @param int $id
      * @param string $size
      *
-     * @return \OCP\Files\File
+     * @return File
      */
-    public function getRecipeImageFileByFolderId($id, $size = 'thumb') {
-        if(!$size) { $size = 'thumb'; }
-        if($size !== 'full' && $size !== 'thumb') { 
-            throw new \Exception('Image size "' . $size . '" not recognised');
+    public function getRecipeImageFileByFolderId($id, $size = 'thumb')
+    {
+        if (!$size) {
+            $size = 'thumb';
+        }
+        if ($size !== 'full' && $size !== 'thumb') {
+            throw new Exception('Image size "' . $size . '" not recognised');
         }
 
         $recipe_folder = $this->root->getById($id);
 
-        if(sizeof($recipe_folder) < 1) { throw new \Exception('Recipe ' . $id . ' not found'); }
-    
+        if (count($recipe_folder) < 1) {
+            throw new Exception('Recipe ' . $id . ' not found');
+        }
+
         $recipe_folder = $recipe_folder[0];
 
         $image_file = null;
@@ -775,24 +887,29 @@ class RecipeService {
 
         $image_file = $recipe_folder->get($image_filename);
 
-        if($image_file && $this->isImage($image_file)) { return $image_file; }
+        if ($image_file && $this->isImage($image_file)) {
+            return $image_file;
+        }
 
-        throw new \Exception('Image file not recognised');
+        throw new Exception('Image file not recognised');
     }
 
     /**
      * Test if file is an image
      *
-     * @param \OCP\Files\File $file
+     * @param File $file
      *
      * @return bool
      */
-    private function isImage($file) {
+    private function isImage($file)
+    {
         $allowedExtensions = ['jpg', 'jpeg', 'png'];
-        if($file->getType() !== 'file') return false;
+        if ($file->getType() !== 'file') {
+            return false;
+        }
         $ext = pathinfo($file->getName(), PATHINFO_EXTENSION);
         $iext = strtolower($ext);
-        if(!in_array($iext, $allowedExtensions)) {
+        if (!in_array($iext, $allowedExtensions)) {
             return false;
         }
         return true;
@@ -801,16 +918,19 @@ class RecipeService {
     /**
      * Test if file is a recipe
      *
-     * @param \OCP\Files\File $file
+     * @param File $file
      *
      * @return bool
      */
-    private function isRecipeFile($file) {
+    private function isRecipeFile($file)
+    {
         $allowedExtensions = ['json'];
-        if($file->getType() !== 'file') return false;
+        if ($file->getType() !== 'file') {
+            return false;
+        }
         $ext = pathinfo($file->getName(), PATHINFO_EXTENSION);
         $iext = strtolower($ext);
-        if(!in_array($iext, $allowedExtensions)) {
+        if (!in_array($iext, $allowedExtensions)) {
             return false;
         }
         return true;
@@ -820,16 +940,19 @@ class RecipeService {
      * @param string $str
      *
      * @return string
-     */  
-    private function cleanUpString($str, $preserve_newlines = false) {
-        if(!$str) { return ''; }
+     */
+    private function cleanUpString($str, $preserve_newlines = false)
+    {
+        if (!$str) {
+            return '';
+        }
 
         $str = strip_tags($str);
 
-        if(!$preserve_newlines) {
+        if (!$preserve_newlines) {
             $str = str_replace(["\r", "\n"], '', $str);
         }
-        
+
         $str = str_replace(["\t", "\\"], '', $str);
 
         $str = html_entity_decode($str);