/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_LIST_WRAPPER_H_
#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_LIST_WRAPPER_H_

#include "constructor_magic.h"

namespace webrtc {
class CriticalSectionWrapper;

class ListItem
{
friend class ListWrapper;

public:
    ListItem(const void* ptr);
    ListItem(const unsigned int item);
    virtual ~ListItem();
    void* GetItem() const;
    unsigned int GetUnsignedItem() const;

protected:
    ListItem* next_;
    ListItem* prev_;

private:
    const void*         item_ptr_;
    const unsigned int  item_;
    DISALLOW_COPY_AND_ASSIGN(ListItem);
};

class ListWrapper
{
public:
    ListWrapper();
    virtual ~ListWrapper();

    // Returns the number of elements stored in the list.
    unsigned int GetSize() const;

    // Puts a pointer to anything last in the list.
    int PushBack(const void* ptr);
    // Puts a pointer to anything first in the list.
    int PushFront(const void* ptr);

    // Puts a copy of the specified integer last in the list.
    int PushBack(const unsigned int item_id);
    // Puts a copy of the specified integer first in the list.
    int PushFront(const unsigned int item_id);

    // Pops the first ListItem from the list
    int PopFront();

    // Pops the last ListItem from the list
    int PopBack();

    // Returns true if the list is empty
    bool Empty() const;

    // Returns a pointer to the first ListItem in the list.
    ListItem* First() const;

    // Returns a pointer to the last ListItem in the list.
    ListItem* Last() const;

    // Returns a pointer to the ListItem stored after item in the list.
    ListItem* Next(ListItem* item) const;

    // Returns a pointer to the ListItem stored before item in the list.
    ListItem* Previous(ListItem* item) const;

    // Removes item from the list.
    int Erase(ListItem* item);

    // Insert list item after existing_previous_item. Please note that new_item
    // must be created using new ListItem(). The map will take ownership of
    // new_item following a successfull insert. If insert fails new_item will
    // not be released by the List
    int Insert(ListItem* existing_previous_item,
               ListItem* new_item);

    // Insert list item before existing_next_item. Please note that new_item
    // must be created using new ListItem(). The map will take ownership of
    // new_item following a successfull insert. If insert fails new_item will
    // not be released by the List
    int InsertBefore(ListItem* existing_next_item,
                     ListItem* new_item);

private:
    void PushBackImpl(ListItem* item);
    void PushFrontImpl(ListItem* item);

    CriticalSectionWrapper* critical_section_;
    ListItem* first_;
    ListItem* last_;
    unsigned int size_;
    DISALLOW_COPY_AND_ASSIGN(ListWrapper);
};
} //namespace webrtc

#endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_LIST_WRAPPER_H_