From 775fbc9a75f57ef66a4659778a0017753f34bcab Mon Sep 17 00:00:00 2001
From: Eric Xu <xeric.2002@gmail.com>
Date: Fri, 21 May 2021 23:33:23 -0400
Subject: [PATCH] Rewrite setIndex(int) to pass unit tests

Original did not cover the case of when streams is empty and
documentation does not specify any input restrictions.

There's an ambiguity with broadcasting an event between the
documentation and the actual code (see TODO).
---
 .../newpipe/player/playqueue/PlayQueue.java   | 28 +++++++++++++++----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/app/src/main/java/org/schabi/newpipe/player/playqueue/PlayQueue.java b/app/src/main/java/org/schabi/newpipe/player/playqueue/PlayQueue.java
index a5fa949de..46627e12e 100644
--- a/app/src/main/java/org/schabi/newpipe/player/playqueue/PlayQueue.java
+++ b/app/src/main/java/org/schabi/newpipe/player/playqueue/PlayQueue.java
@@ -135,18 +135,36 @@ public abstract class PlayQueue implements Serializable {
     public synchronized void setIndex(final int index) {
         final int oldIndex = getIndex();
 
-        int newIndex = index;
+        final int newIndex;
+
         if (index < 0) {
             newIndex = 0;
+        } else if (index < streams.size()) {
+            // Regular assignment for index in bounds
+            newIndex = index;
+        } else if (streams.isEmpty()) {
+            // Out of bounds from here on
+            // Need to check if stream is empty to prevent arithmetic error and negative index
+            newIndex = 0;
+        } else if (isComplete()) {
+            // Circular indexing
+            newIndex = index % streams.size();
+        } else {
+            // Index of last element
+            newIndex = streams.size() - 1;
         }
-        if (index >= streams.size()) {
-            newIndex = isComplete() ? index % streams.size() : streams.size() - 1;
-        }
+
+        queueIndex.set(newIndex);
+
         if (oldIndex != newIndex) {
             history.add(streams.get(newIndex));
         }
 
-        queueIndex.set(newIndex);
+        /*
+        TODO: Documentation states that a SelectEvent will only be emitted if the new index is...
+        different from the old one but this is emitted regardless? Not sure what this what it does
+        exactly so I won't touch it
+         */
         broadcast(new SelectEvent(oldIndex, newIndex));
     }