#87 Add warning when loop metadata is missing for AudioStreamWAV (#104)

* Add warning for AudioStreamWAV in audio_cue.gd

* Fix comments on the PR

addons/popochiu/engine/audio_manager/audio_cue.gd

@@ -93,9 +93,16 @@ func set_loop(value: bool) -> void:
 		'AudioStreamOggVorbis', 'AudioStreamMP3':
 			audio.loop = value
 		'AudioStreamWAV':
-			(audio as AudioStreamWAV).loop_mode =\
-			AudioStreamWAV.LOOP_FORWARD if value\
-			else AudioStreamWAV.LOOP_DISABLED
+			if (audio as AudioStreamWAV).get_loop_end() == 0 && value:
+				PopochiuUtils.print_warning(
+					"[b]%s[/b]" % resource_name +\
+					" does not have the correct metadata to loop, please check" +\
+					" AudioStreamWAV documentation"
+				)
+			else:
+				(audio as AudioStreamWAV).loop_mode =\
+				AudioStreamWAV.LOOP_FORWARD if value\
+				else AudioStreamWAV.LOOP_DISABLED
 
 	notify_property_list_changed()