/***************************************************************************
 *   Copyright (C) 2005 by Joris Guisson                                   *
 *   joris.guisson@gmail.com                                               *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.             *
 ***************************************************************************/
#ifndef BTBNODE_H
#define BTBNODE_H

#include <QList>
#include <QVariant>
#include <QStringList>
#include <util/constants.h>
#include <ktorrent_export.h>
#include "value.h"


namespace bt
{
	class BListNode;

	/**
	 * @author Joris Guisson
	 * @brief Base class for a node in a b-encoded piece of data
	 * 
	 * There are 3 possible pieces of data in b-encoded piece of data.
	 * This is the base class for all those 3 things.
	*/
	class KTORRENT_EXPORT BNode
	{
	public:
		enum Type
		{
			VALUE,DICT,LIST
		};
		
		/**
		 * Constructor, sets the Type, and the offset into 
		 * the data.
		 * @param type Type of node
		 * @param off The offset into the data
		 */
		BNode(Type type,Uint32 off);
		virtual ~BNode();

		/// Get the type of node
		Type getType() const {return type;}

		/// Get the offset in the bytearray where this node starts.
		Uint32 getOffset() const {return off;}

		/// Get the length this node takes up in the bytearray.
		Uint32 getLength() const {return len;}

		/// Set the length
		void setLength(Uint32 l) {len = l;}

		/// Print some debugging info
		virtual void printDebugInfo() = 0;
	private:
		Type type;
		Uint32 off,len;
	};

	/**
	 * @author Joris Guisson
	 * @brief Represents a value (string,bytearray or int) in bencoded data
	 *
	 * @todo Use QVariant
	 */
	class KTORRENT_EXPORT BValueNode : public BNode
	{
		Value value;
	public:
		BValueNode(const Value & v,Uint32 off);
		virtual ~BValueNode();
		
		const Value & data() const {return value;}
		void printDebugInfo();
	};

	/**
	 * @author Joris Guisson
	 * @brief Represents a dictionary in bencoded data
	 *
	 */
	class KTORRENT_EXPORT BDictNode : public BNode
	{
		struct DictEntry
		{
			QByteArray key;
			BNode* node;
		};
		QList<DictEntry> children;
	public:
		BDictNode(Uint32 off);
		virtual ~BDictNode();
		
		/// Get a list of keys
		QStringList keys() const;
		
		/**
		 * Insert a BNode in the dictionary.
		 * @param key The key
		 * @param node The node
		 */
		void insert(const QByteArray & key,BNode* node);
		
		/**
		 * Get a BNode.
		 * @param key The key
		 * @return The node or 0 if there is no node with has key @a key 
		 */
		BNode* getData(const QString & key);

		/**
		 * Get a BListNode.
		 * @param key The key
		 * @return The node or 0 if there is no list node with has key @a key
		 */
		BListNode* getList(const QString & key);

		/**
		 * Get a BDictNode.
		 * @param key The key
		 * @return The node or 0 if there is no dict node with has key @a key
		 */
		BDictNode* getDict(const QString & key);
		
		/**
		 * Get a BDictNode.
		 * @param key The key
		 * @return The node or 0 if there is no dict node with has key @a key
		 */
		BDictNode* getDict(const QByteArray & key);

		/**
		 * Get a BValueNode.
		 * @param key The key
		 * @return The node or 0 if there is no value node with has key @a key
		 */
		BValueNode* getValue(const QString & key);
		
		/// Same as getValue, except directly returns an int, if something goes wrong, an error will be thrown
		int getInt(const QString & key);
		
		/// Same as getValue, except directly returns a qint64, if something goes wrong, an error will be thrown
		qint64 getInt64(const QString & key);
		
		/// Same as getValue, except directly returns a QString, if something goes wrong, an error will be thrown
		QString getString(const QString & key,QTextCodec* tc);
		
		/// Same as getValue, except directly returns an QByteArray, if something goes wrong, an error will be thrown
		QByteArray getByteArray(const QString & key);
		
		void printDebugInfo();
	};

	/**
	 * @author Joris Guisson
	 * @brief Represents a list in bencoded data
	 *
	 */
	class KTORRENT_EXPORT BListNode : public BNode
	{
		QList<BNode*> children;
	public:
		BListNode(Uint32 off);
		virtual ~BListNode();

		/**
		 * Append a node to the list.
		 * @param node The node
		 */
		void append(BNode* node);
		void printDebugInfo();

		/// Get the number of nodes in the list.
		Uint32 getNumChildren() const {return children.count();}
		
		/**
		 * Get a node from the list
		 * @param idx The index
		 * @return The node or 0 if idx is out of bounds
		 */
		BNode* getChild(Uint32 idx) {return children.at(idx);}

		/**
		 * Get a BListNode.
		 * @param idx The index
		 * @return The node or 0 if the index is out of bounds or the element
		 * 	at postion @a idx isn't a BListNode.
		 */
		BListNode* getList(Uint32 idx);

		/**
		 * Get a BDictNode.
		 * @param idx The index
		 * @return The node or 0 if the index is out of bounds or the element
		 * 	at postion @a idx isn't a BDictNode.
		 */
		BDictNode* getDict(Uint32 idx);

		/**
		 * Get a BValueNode.
		 * @param idx The index
		 * @return The node or 0 if the index is out of bounds or the element
		 * 	at postion @a idx isn't a BValueNode.
		 */
		BValueNode* getValue(Uint32 idx);
		
		/// Same as getValue, except directly returns an int, if something goes wrong, an error will be thrown
		int getInt(Uint32 idx);
		
		/// Same as getValue, except directly returns a qint64, if something goes wrong, an error will be thrown
		qint64 getInt64(Uint32 idx);
		
		/// Same as getValue, except directly returns a QString, if something goes wrong, an error will be thrown
		QString getString(Uint32 idx,QTextCodec* tc);
		
		/// Same as getValue, except directly returns an QByteArray, if something goes wrong, an error will be thrown
		QByteArray getByteArray(Uint32 idx);
	};
}

#endif
