/*****************************************************
*  
*  Copyright 2009 Akamai Technologies, Inc.  All Rights Reserved.
*  
*****************************************************
*  The contents of this file are subject to the Mozilla Public License
*  Version 1.1 (the "License"); you may not use this file except in
*  compliance with the License. You may obtain a copy of the License at
*  http://www.mozilla.org/MPL/
*   
*  Software distributed under the License is distributed on an "AS IS"
*  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
*  License for the specific language governing rights and limitations
*  under the License.
*   
*  
*  The Initial Developer of the Original Code is Akamai Technologies, Inc.
*  Portions created by Akamai Technologies, Inc. are Copyright (C) 2009 Akamai 
*  Technologies, Inc. All Rights Reserved. 
*  
*  Contributor(s): Adobe Systems Incorporated.
* 
*****************************************************/
package org.osmf.net
{
	import flash.events.NetStatusEvent;
	import flash.net.NetStream;
	
	import org.osmf.events.DynamicStreamEvent;
	import org.osmf.traits.DynamicStreamTrait;
	import org.osmf.utils.OSMFStrings;

	[ExcludeClass]
	
	/**
	 * @private
	 * 
	 * The NetStreamDynamicStreamTrait class extends DynamicStreamTrait for NetStream-based
	 * dynamic streaming.
	 */   
	public class NetStreamDynamicStreamTrait extends DynamicStreamTrait
	{
		/**
		 * Constructor.
		 * 
		 * @param netStream The NetStream object the class will work with.
		 * @param switchManager The NetStreamSwitchManagerBase which will perform MBR switches.
		 * @param dsResource The DynamicStreamingResource the class will use.
		 *  
		 *  @langversion 3.0
		 *  @playerversion Flash 10
		 *  @playerversion AIR 1.5
		 *  @productversion OSMF 1.0
		 */
		public function NetStreamDynamicStreamTrait(netStream:NetStream, switchManager:NetStreamSwitchManagerBase, dsResource:DynamicStreamingResource)
		{
			super(switchManager.autoSwitch, switchManager.currentIndex, dsResource.streamItems.length);	
			
			this.netStream = netStream;
			this.switchManager = switchManager;
			this.dsResource = dsResource;
									
			netStream.addEventListener(NetStatusEvent.NET_STATUS, onNetStatus);
			NetClient(netStream.client).addHandler(NetStreamCodes.ON_PLAY_STATUS, onPlayStatus);
		}
		
		override public function dispose():void
		{
			netStream = null;
			switchManager = null;
		}
		
		/**
		 * @private
		 */
		override public function getBitrateForIndex(index:int):Number
		{
			if (index > numDynamicStreams - 1 || index < 0)
			{
				throw new RangeError(OSMFStrings.getString(OSMFStrings.STREAMSWITCH_INVALID_INDEX));
			}

			return dsResource.streamItems[index].bitrate;
		}	
				
		/**
		 * @private
		 */
		override protected function switchingChangeStart(newSwitching:Boolean, index:int):void
		{
			if (newSwitching && !inSetSwitching)
			{
				// Keep track of the target index, we don't want to begin
				// the switch now since our switching state won't be
				// updated until the switchingChangeEnd method is called.
				indexToSwitchTo = index;
			}
		}
		
		/**
		 * @private
		 */
		override protected function switchingChangeEnd(index:int):void
		{
			super.switchingChangeEnd(index);
			
			if (switching && !inSetSwitching)
			{
				switchManager.switchTo(indexToSwitchTo);
			}
		}
			
		/**
		 * @private
		 */
		override protected function autoSwitchChangeStart(value:Boolean):void
		{
			switchManager.autoSwitch = value;
		}
		
		/**
		 * @private
		 */ 
		override protected function maxAllowedIndexChangeStart(value:int):void
		{
			switchManager.maxAllowedIndex = value;
		}
						
		private function onNetStatus(event:NetStatusEvent):void
		{			
			switch (event.info.code)
			{
				case NetStreamCodes.NETSTREAM_PLAY_TRANSITION:
					// This switch is driven by the NetStream, we set a member
					// variable so that we don't assume it's being requested by
					// the client (and thus trigger a second switch).
					inSetSwitching = true;
					
					setSwitching(true, dsResource.indexFromName(event.info.details));
					
					inSetSwitching = false;		
					break;
				case NetStreamCodes.NETSTREAM_PLAY_FAILED:					
					setSwitching(false, currentIndex);					
					break;
			}			
		}
		
		private function onPlayStatus(event:Object):void
		{
			switch (event.code)
			{
				case NetStreamCodes.NETSTREAM_PLAY_TRANSITION_COMPLETE:
					// When a switch finishes, make sure our current index and
					// switching state reflect the changes to the NetStream.
					setSwitching(false, switchManager.currentIndex);
					break;
			}
		}
		
		private var netStream:NetStream;
		private var switchManager:NetStreamSwitchManagerBase;
		private var inSetSwitching:Boolean;
		private var dsResource:DynamicStreamingResource;
		private var indexToSwitchTo:int;	
	}
}