From b6adcc433e8738ad93effa4e30b9cda37f58a952 Mon Sep 17 00:00:00 2001
From: Jonathan Netley <jpbnetley@gmail.com>
Date: Sun, 19 Apr 2020 22:18:44 +0200
Subject: [PATCH] database cleanup

---
 .../scala/Util/DataBuilder/Processing.scala   | 38 ++++++++++---------
 src/main/scala/Util/Database/Database.scala   | 22 +++++++----
 2 files changed, 35 insertions(+), 25 deletions(-)

diff --git a/src/main/scala/Util/DataBuilder/Processing.scala b/src/main/scala/Util/DataBuilder/Processing.scala
index e140eb5..3f45543 100644
--- a/src/main/scala/Util/DataBuilder/Processing.scala
+++ b/src/main/scala/Util/DataBuilder/Processing.scala
@@ -10,8 +10,6 @@ import org.bson.Document
 
 import scala.concurrent.Await
 import scala.concurrent.duration.Duration
-import scala.reflect.io.File
-import Util.Logging.log
 import Util.ErrorHandler._
 import Util.Models.OrderedFile
 
@@ -25,22 +23,26 @@ object Processing {
     */
   def csvFiles(csvFiles: List[OrderedFile])
               (implicit database: Database.type): Task[Either[Exception, Unit]] = {
-    Task.wander(csvFiles) { orderedFile =>
-      println(s"Processing file ${orderedFile.index + 1} of ${csvFiles.length} file name: ${orderedFile.file.name}")
-      (for {
-        fileLines       <- EitherT(FileHelper.extractCsvFileLines(orderedFile.file))
-        headers         =  fileLines.headOption.map(_.split(',').toList)
-        lineItems       =  fileLines.drop(1)
-        collectionName  =  orderedFile.file.name.replace(".csv", "").toLowerCase
-        documentResult  <- EitherT(buildMongoDocuments(headers, lineItems))
-        db              <- EitherT.right[Exception](database.getDatabase)
-        dbInsert        <- EitherT.rightT[Task, Exception](db.getCollection[Document](collectionName).insertMany(documentResult))
-      } yield {
-        println(s"Inserting into db: $dbInsert")
-        Await.result(dbInsert.toFuture(), Duration.Inf)
-        println(s"Done processing file ${orderedFile.index + 1}")
-      }).value
-    }.map { result =>
+    val insertion = {
+      Task.wander(csvFiles) { orderedFile =>
+        println(s"Processing file ${orderedFile.index + 1} of ${csvFiles.length} file name: ${orderedFile.file.name}")
+        (for {
+          fileLines <- EitherT(FileHelper.extractCsvFileLines(orderedFile.file))
+          headers = fileLines.headOption.map(_.split(',').toList)
+          lineItems = fileLines.drop(1)
+          collectionName = orderedFile.file.name.replace(".csv", "").toLowerCase
+          documentResult <- EitherT(buildMongoDocuments(headers, lineItems))
+          db <- EitherT(database.getDatabase)
+          dbInsert <- EitherT.rightT[Task, Exception](db.getCollection[Document](collectionName).insertMany(documentResult))
+        } yield {
+          println(s"Inserting into db: $dbInsert")
+          Await.result(dbInsert.toFuture(), Duration.Inf)
+          println(s"Done processing file ${orderedFile.index + 1}")
+        }).value
+      }
+    }
+
+    insertion.map { result =>
       val (errors, _) = result.separate
       errors.headOption.map(error).toLeft(())
     }
diff --git a/src/main/scala/Util/Database/Database.scala b/src/main/scala/Util/Database/Database.scala
index f2becbb..2b0559f 100644
--- a/src/main/scala/Util/Database/Database.scala
+++ b/src/main/scala/Util/Database/Database.scala
@@ -3,11 +3,14 @@ import com.mongodb.{MongoClientSettings, MongoCredential, ServerAddress}
 import monix.eval.Task
 import org.mongodb.scala.{MongoClient, MongoDatabase}
 import Util.ErrorHandler._
+import cats.implicits._
 
 import scala.jdk.CollectionConverters._
 
 case object Database {
 
+  private var mongoClient: Option[MongoClient] = None
+
   /** builds mongo settings with auth
     *
     * @param authUser on the db
@@ -54,20 +57,25 @@ case object Database {
     }
   }
 
-  private val databaseName: String                  = sys.env.get("mongo_db_name").fold(throw error("environment variables not set for db name"))(identity)
-  private val settings: MongoClientSettings.Builder = settingsBuilder().fold(throw error("environment variables not set for db"))(identity)
-  private val mongoClient: MongoClient              = MongoClient(settings.build())
-  private val database: MongoDatabase               = mongoClient.getDatabase(databaseName)
-
   /** Returns thee database instance
     *
     * @return
     */
-  def getDatabase: Task[MongoDatabase] = Task(database)
+  def getDatabase: Task[Either[Exception, MongoDatabase]] = Task.eval {
+    for {
+      databaseName <- Either.fromOption(sys.env.get("mongo_db_name"), error("environment variables not set for db name"))
+      settings     <- Either.fromOption(settingsBuilder(), error("environment variables not set for db"))
+      mongoClient  =  MongoClient(settings.build()).some
+      mClient      <- Either.fromOption(mongoClient, error("mongo client could not be defined"))
+    } yield mClient.getDatabase(databaseName)
+  }
 
   /** Closes the mongo connection
     *
     */
-  def close(): Unit = mongoClient.close()
+  def close(): Unit = mongoClient match {
+    case Some(db) => db.close()
+    case None     => ()
+  }
 
 }