package
{
	
	/*@Author - Gaurav Pandey
	@Description - Part of a Flex-Collection API*/
	
	public class LRUCache
	{
		[Bindable]
		public var dict : MyDictionary = null;
		
		[Bindable]
		public var list : MyLinkedList = null;
		
		[Bindable]
		private var maxCacheSizeLimit : int = 0;
		
		public function LRUCache(maxCacheSize : int = 10) : void
		{
			dict = new MyDictionary();
			list = new MyLinkedList();
			this.maxCacheSizeLimit = maxCacheSize;
		}
		
		public function insertInCache(keyvalue : Object) : void
		{
			if(this == null)
				throw new ReferenceError("Object instance is null");
			if(!(this is LRUCache))
				throw new MDIllegalObjectException("Object referenced is not a LRUCache");
			if(keyvalue == null)
				throw new ArgumentError("Object is Null");
			
			var node : MyNode = null;
			if(dict.containsKey(keyvalue))
			{
				var tempNode : MyNode = dict.getValue(keyvalue) as MyNode;
				if(tempNode.next != null)
					tempNode.next.prev = tempNode.prev;
				if(tempNode.prev != null)
					tempNode.prev.next = tempNode.next;
				tempNode.next = null;
				tempNode.prev = null;
				dict.removeKey(keyvalue);
			}
			else
				if(dict.getSize() == maxCacheSizeLimit)
					removeCacheElement();
			dict.insertKey(keyvalue, list.insertAtStartLRU(keyvalue, keyvalue));
		}
		
		public function insertKeyInCache(key : Object, value : Object) : void
		{
			if(this == null)
				throw new ReferenceError("Object instance is null");
			if(!(this is LRUCache))
				throw new MDIllegalObjectException("Object referenced is not a LRUCache");
			if(key == null)
				throw new ArgumentError("Key is Null");
			if(value == null)
				throw new ArgumentError("Value is Null");
			
			var node : MyNode = null;
			if(dict.containsKey(key))
			{
				var tempNode : MyNode = dict.getValue(key) as MyNode;
				if(tempNode.next != null)
					tempNode.next.prev = tempNode.prev;
				if(tempNode.prev != null)
					tempNode.prev.next = tempNode.next;
				tempNode.next = null;
				tempNode.prev = null;
				dict.removeKey(key);
			}
			else
				if(dict.getSize() == maxCacheSizeLimit)
					removeCacheElement();
			dict.insertKey(key, list.insertAtStartLRU(key, value));
		}
		
		public function removeCacheElement() : void
		{
			dict.removeKey(list.removeAtEnd().key);
		}
		
		public function getData(key : Object) : Object
		{
			if(this == null)
				throw new ReferenceError("Object instance is null");
			if(!(this is LRUCache))
				throw new MDIllegalObjectException("Object referenced is not a LRUCache");
			if(key == null)
				throw new ArgumentError("Key is Null");
				
			var node : MyNode = null;
			if(dict.containsKey(key))
			{
				return (dict.getValue(key) as MyNode).data;
			}
			else
			{
				trace("Key does not exist");
				return null;
			}
		}
		
		public function clearCache() : void
		{
			if(this == null)
				throw new ReferenceError("Object instance is null");
			if(!(this is LRUCache))
				throw new MDIllegalObjectException("Object referenced is not a LRUCache");
				
			
		}
		
		public function getCacheSize() : int
		{
			if(this == null)
				throw new ReferenceError("Object instance is null");
			if(!(this is LRUCache))
				throw new MDIllegalObjectException("Object referenced is not a LRUCache");
				
			return dict.getSize();
		} 
	}
}