From e88fcfb1c71cb03691b38ff681b409d8501ec3fd Mon Sep 17 00:00:00 2001
From: Hippolyte Thomas <contact@hippolyte-thomas.fr>
Date: Sun, 28 Jan 2024 21:01:25 +1300
Subject: [PATCH] fix(db): issue with results consistency

---
 src/Service/MongoDB.php | 106 ++++++++++++++++++++++++++++++++++------
 1 file changed, 91 insertions(+), 15 deletions(-)

diff --git a/src/Service/MongoDB.php b/src/Service/MongoDB.php
index 941f33c..ff478c9 100644
--- a/src/Service/MongoDB.php
+++ b/src/Service/MongoDB.php
@@ -7,6 +7,7 @@
 use MongoDB\BSON\Regex;
 use MongoDB\Collection;
 use MongoDB\Client as Mongo;
+use MongoDB\Database;
 use MongoDB\Driver\CursorInterface;
 use Psr\Log\LoggerInterface;
 
@@ -19,24 +20,33 @@ public function __construct(
 	) { }
 
 	/**
-	 * Retrieves a MongoDB collection or returns false on failure
-	 * @return Collection|false The MongoDB collection or false if the connection fails.
+	 * Retrieves a MongoDB database or returns false on failure
+	 * @return Database|false The MongoDB database or false if the connection fails.
 	 */
-    private function getCollection(): Collection|false
+	private function getDb(): Database|false
 	{
 		// Create a new MongoDB client instance
 		$mongo = new Mongo($this->mongoDbUrl);
 
-		// Test the connection to the MongoDB server and return the collection
+		// Test the connection to the MongoDB server and return the database
 		try {
 			$mongo->{$this->mongoDbName}->command(['ping' => 1]);
-			return $mongo->{$this->mongoDbName}->journal;
+			return $mongo->{$this->mongoDbName};
 		} catch (Exception $e) {
 			$this->logger->error('[MongoDB] Exception: {exception}', [
 				'exception' => $e->getMessage(),
 			]);
 		}
 		return false;
+	}
+
+	/**
+	 * Retrieves a MongoDB collection or returns false on failure
+	 * @return Collection|false The MongoDB collection or false if the connection fails.
+	 */
+    private function getCollection(): Collection|false
+	{
+		return $this->getDb()?->journal ?? false;
     }
 
 	/**
@@ -45,7 +55,7 @@ private function getCollection(): Collection|false
 	 */
 	public function isConnected(): bool
 	{
-		return $this->getCollection() !== false;
+		return $this->getDb() !== false;
 	}
 
 	/**
@@ -120,15 +130,21 @@ public function findOne(int $user_id, DateTime $date): array|false
 	 */
 	public function retrieveUserNutritionData(int $user_id, array $date_list, array $fields_group, int $sort = -1, int $limit = 100, int $offset = 0, array $filters_group = []): CursorInterface|false
 	{
-		$collection = $this->getCollection();
-		if (!$collection) return false;
+		// Build query for the View
+		$aggregate_query = $this->getNutritionAggregateQuery();
+
+		// Check if the view exist otherwise create it
+		$view = $this->getView("nutrition", "journal", $aggregate_query);
+		if (!$view) return false;
+
+		// Prepare the query
 		$match = ['user_id' => $user_id];
 
 		// Prepare the date list for the request
 		if (empty($date_list)) return false;
 		$dates = [];
 		foreach ($date_list as $date) {
-			$dates[] = [ 'entry.dateTime' => new Regex("{$date}.*") ];
+			$dates[] = [ 'dateTime' => new Regex("{$date}.*") ];
 		}
 		$match['$or'] = $dates;
 
@@ -143,18 +159,15 @@ public function retrieveUserNutritionData(int $user_id, array $date_list, array
 		// Add filters for the request
 		$match = array_merge($match, $filters_group);
 
-		// Search into the collection and return results as an array, if successfully found
+		// Search into the view and return results as an array, if successfully found
 		try {
-			return $collection->aggregate([
+			return $view->aggregate([
 				[
 					'$match' => $match
 				],
-				[
-					'$sort' => [ 'timestamp' => -1 ]
-				],
 				[
 					'$group' => [
-						'_id' => '$entry.dateTime',
+						'_id' => '$dateTime',
 						'data' => [
 							'$first' => !empty($fields) ? $fields : '$$ROOT.nutrition'
 						]
@@ -182,4 +195,67 @@ public function retrieveUserNutritionData(int $user_id, array $date_list, array
 		}
 		return false;
 	}
+
+	/**
+	 * Get or create a MongoDB view
+	 * @param  string $view_name 		The name of the MongoDB view
+	 * @param  string $collection_name 	The name of the collection on which the view is based
+	 * @param  array  $aggregate_query 	An array representing the aggregation pipeline to create the view
+	 * @return Collection|false Returns the MongoDB view (Collection) if it exists or was successfully created. Returns false on failure
+	 */
+	private function getView(string $view_name, string $collection_name = "", array $aggregate_query = []): Collection|false
+	{
+		$db = $this->getDb();
+		if (!$db) return false;
+
+		// Check if the view exist
+		$collections = $db->listCollections();
+		foreach ($collections as $collection) {
+			if ($collection->getType() === "view" && $collection->getName() === $view_name) {
+				return $db->{$view_name};
+			}
+		}
+		if (empty($aggregate_query) || empty($collection_name)) return false;
+
+		// Create the view if it doesn't exist
+		try {
+			$db->command([
+				'create' => $view_name,
+				'viewOn' => $collection_name,
+				'pipeline' => $aggregate_query
+			]);
+		} catch (Exception $e) {
+			$this->logger->error('[MongoDB] Exception: {exception}', [
+				'exception' => $e->getMessage(),
+			]);
+			return false;
+		}
+		return $this->getView($view_name);
+	}
+
+	private function getNutritionAggregateQuery(): array
+	{
+		return [
+			[
+				'$sort' => [ 'timestamp' => -1 ]
+			],
+			[
+				'$group' => [
+					'_id' => [
+						'user_id' => '$user_id',
+						'dateTime' => '$entry.dateTime'
+					],
+					'nutrition' => [
+						'$first' => '$$ROOT.nutrition'
+					],
+					'dateTime' => [
+						'$first' => '$$ROOT.entry.dateTime'
+					],
+					'user_id' => [
+						'$first' => '$$ROOT.user_id'
+					]
+				]
+			]
+		];
+	}
 }