Add MongoDBClient model (#18)

backend-services/feed-service/app/models/MongoDBClient.scala

+package models
+
+import org.mongodb.scala.{MongoClient, MongoDatabase, MongoCollection, Document, FindObservable, Observer, Observable}
+import org.mongodb.scala.model.{Filters, Projections, Sorts}
+import org.bson.conversions.Bson
+
+import scala.concurrent.ExecutionContext.Implicits.global
+import scala.concurrent.Future
+import scala.util.{Success, Failure, Try}
+
+
+/**
+ * A MongoDB client for connecting to and interacting with a MongoDB database.
+ * 
+ * @constructor Creates a new instance of the MongoDBClient class.
+ */
+class MongoDBClient {
+    // Connects to a MongoDB Client when class is constructed
+    private var client: MongoClient = this.connect()
+
+    /**
+     * Connects to a MongoDB database using the default MongoDB connection string.
+     * 
+     * @return A MongoClient instance.
+     */
+    def connect(): MongoClient = {
+        MongoClient("mongodb://localhost:27017/")
+    }
+
+    /**
+     * Gets a reference to a MongoDB database.
+     * 
+     * @param database The name of the database to retrieve.
+     * @return A Future containing a MongoDatabase instance.
+     */
+    def getDatabase(database: String): Future[MongoDatabase] = Future {
+        client.getDatabase(database)
+    }
+
+    /**
+     * Gets a reference to a MongoDB collection within a database.
+     * 
+     * @param database The MongoDatabase instance containing the desired collection.
+     * @param collection The name of the collection to retrieve.
+     * @return A Future containing a MongoCollection instance.
+     */
+    def getCollection(database: MongoDatabase, collection: String): Future[MongoCollection[Document]] = Future {
+        database.getCollection(collection)
+    }
+
+    /**
+     * Finds documents in a MongoDB collection.
+     * 
+     * @param collection The MongoCollection instance to search.
+     * @param filter A Bson filter to apply to the search.
+     * @param projection A Bson projection to apply to the search.
+     * @param sort A Bson sort to apply to the search.
+     * @return A Future containing a sequence of matching documents as Documents.
+     */
+    def find(
+        collection: MongoCollection[Document], 
+        filter: Bson = Filters.empty(), 
+        projection: Bson = Projections.excludeId(),
+        sort: Bson = Sorts.ascending("_id")
+    ): Future[Seq[Document]] = {
+        collection.find(filter)
+        .projection(projection)
+        .sort(sort)
+        .toFuture()
+    }
+
+    /**
+     * Inserts a document into a MongoDB collection.
+     * 
+     * @param collection The MongoCollection instance to insert into.
+     * @param document The document to insert.
+     * @return A Future containing the ID of the inserted document.
+     * @throws RuntimeException if the insertion was not acknowledged by the database.
+     */
+    def insertOne(collection: MongoCollection[Document], document: Document): Future[String] = {
+        val futureResult = collection.insertOne(document).toFuture()
+        
+        futureResult.map(result => {
+            if (result.wasAcknowledged()) {
+                // Grab the generated ID of the inserted document
+                result.getInsertedId().asObjectId.getValue().toString()
+            } else {
+                throw new RuntimeException("Insertion was not acknowledged")
+            }
+        })
+    }
+}

backend-services/feed-service/build.sbt

@@ -15,3 +15,4 @@ libraryDependencies += "org.scalatestplus.play" %% "scalatestplus-play" % "5.0.0
 
 // Adds additional packages into conf/routes
 // play.sbt.routes.RoutesKeys.routesImport += "com.daily.binders._"
+libraryDependencies += "org.mongodb.scala" %% "mongo-scala-driver" % "4.3.0"