Load existing state machines from the disk #19

README.md

@@ -71,6 +71,7 @@ There can be different backends which manage the state machine.
 
 This backend uses the GraphDB [Neo4J](https://neo4j.com/) (community edition) with an embedded database.
 It uses [Neo4J-OGM](https://neo4j.com/docs/ogm-manual/current/) to map our types to the graph database.
+All state machines are stored in separate directories in `$HOME/.guistatemachines`.
 
 Each state machine is represented by a separate graph database stored in a separate directory.
 The nodes all have the property "sutState" which contains the corresponding SUT state serialized as XML.

src/main/scala/de/retest/guistatemachine/api/GuiStateMachineApi.scala

@@ -1,4 +1,6 @@
 package de.retest.guistatemachine.api
+import java.nio.file.Paths
+
 import de.retest.guistatemachine.api.impl.GuiStateMachineApiImpl
 import de.retest.guistatemachine.api.neo4j.GuiStateMachineApiNeo4J
 
@@ -38,12 +40,17 @@ trait GuiStateMachineApi {
 }
 
 object GuiStateMachineApi {
-  val default = new GuiStateMachineApiImpl
 
   /**
     * @return The standard implementaiton of the API.
     */
   def apply(): GuiStateMachineApi = default
 
+  /**
+    * The directory in which all GUI state machines will be persisted.
+    */
+  val StateMachinesDir = Paths.get(System.getProperty("user.home"), ".guistatemachines").toAbsolutePath.toString
+
+  val default = new GuiStateMachineApiImpl
   val neo4j = new GuiStateMachineApiNeo4J
 }

src/main/scala/de/retest/guistatemachine/api/neo4j/GuiStateMachineApiNeo4J.scala

@@ -1,17 +1,18 @@
 package de.retest.guistatemachine.api.neo4j
 
-import java.io.File
+import java.io.{File, FilenameFilter}
+import java.nio.file.Paths
 
 import com.typesafe.scalalogging.Logger
-import de.retest.guistatemachine.api.impl.GuiStateMachineImpl
 import de.retest.guistatemachine.api.{GuiStateMachine, GuiStateMachineApi}
 
 import scala.collection.concurrent.TrieMap
 
 class GuiStateMachineApiNeo4J extends GuiStateMachineApi {
-  private val logger = Logger[GuiStateMachineImpl]
+  private val logger = Logger[GuiStateMachineApiNeo4J]
   private val stateMachines = TrieMap[String, GuiStateMachine]()
-  // TODO #19 Load existing state machines from the disk.
+
+  loadExistingStateMachinesFromDisk()
 
   override def createStateMachine(name: String): GuiStateMachine = {
     val uri = getUri(name)
@@ -41,5 +42,27 @@ class GuiStateMachineApiNeo4J extends GuiStateMachineApi {
     removeStateMachine(name)
   } // TODO #19 Removes from disk?
 
-  private def getUri(name: String): String = new File(name).toURI.toString
+  private def getUri(name: String): String = Paths.get(GuiStateMachineApi.StateMachinesDir, name).toUri.toString
+
+  private def getExistingFolders(): Seq[String] =
+    new File(GuiStateMachineApi.StateMachinesDir).list(new FilenameFilter() {
+      def accept(dir: File, name: String): Boolean = new File(dir, name).isDirectory
+    })
+
+  private def loadExistingStateMachinesFromDisk(): Unit = {
+    val dir = new File(GuiStateMachineApi.StateMachinesDir)
+
+    if (!dir.exists()) {
+      dir.mkdir()
+
+      logger.info("No existing graphs in {}.", dir.toString)
+    } else {
+      logger.info("Loading existing graphs from {}.", dir.toString)
+
+      getExistingFolders() foreach { f =>
+        logger.info("Loading graph {}.", f)
+        createStateMachine(f)
+      }
+    }
+  }
 }