Add logic for playlist

.gitignore

@@ -46,4 +46,7 @@ atlassian-ide-plugin.xml
 com_crashlytics_export_strings.xml
 crashlytics.properties
 crashlytics-build.properties
-fabric.properties
+fabric.properties
+
+# Apple files
+*.DS_Store

src/main/java/io/zipcoder/Music.java

@@ -9,6 +9,52 @@ public Music(String[] playList){
     }
 
     public Integer selection(Integer startIndex, String selection){
-        return null;
+
+        int counterCurrentLocation = 0;
+        int counterUpArrow = 0;
+        int counterDownArrow = 0;
+        int counterNumberSteps = 0;
+
+        // up arrow direction
+        counterCurrentLocation = playList.length - 1;
+        if (startIndex != playList.length - 1) counterCurrentLocation = startIndex + 1;
+        counterUpArrow ++;
+
+
+        while (counterCurrentLocation != startIndex){
+            if (selection.equals(playList[counterCurrentLocation])) {
+                break;
+            }
+            // if we hit the end of the loop, reset and start from beginning of the list
+            if (counterCurrentLocation >= playList.length - 1){
+                counterCurrentLocation = 0;
+            }
+            counterCurrentLocation ++;
+            counterUpArrow ++;
+        }
+
+
+
+        // down arrow direction
+        counterCurrentLocation = 0;
+        if (startIndex != 0) counterCurrentLocation = startIndex - 1;
+        counterDownArrow ++;
+        counterNumberSteps = counterUpArrow;
+
+        while (counterCurrentLocation != startIndex){
+            if (selection.equals(playList[counterCurrentLocation])) {
+                break;
+            }
+            // if we hit the end of the loop, reset and start from beginning of the list
+            if (counterCurrentLocation <= 0){
+                counterCurrentLocation = playList.length;
+            }
+            counterCurrentLocation --;
+            counterDownArrow ++;
+        }
+
+        if (counterDownArrow < counterUpArrow) counterNumberSteps = counterDownArrow;
+
+        return counterNumberSteps;
     }
 }