/*
 * Copyright 2008, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Distributed under the terms of the MIT License.
 */
#ifndef HISTORY_BUFFER_H
#define HISTORY_BUFFER_H

#include <SupportDefs.h>

#include "TerminalLine.h"


struct HistoryLine;
struct TerminalLine;


class HistoryBuffer {
public:
                                                                HistoryBuffer();
                                                                ~HistoryBuffer();

                        status_t                        Init(int32 width, int32 capacity);

                        void                            Clear();

                        int32                           Width() const           { return fWidth; }
                        int32                           Capacity() const        { return fCapacity; }
                        int32                           Size() const            { return fSize; }

        inline  HistoryLine*            LineAt(int32 index) const;
                        TerminalLine*           GetTerminalLineAt(int32 index,
                                                                        TerminalLine* buffer) const;

                        void                            AddLine(const TerminalLine* line);
                        void                            AddEmptyLines(int32 count);
                        void                            DropLines(int32 count);

private:
                        HistoryLine*            _AllocateLine(int32 attributesRuns,
                                                                        int32 byteLength);
        inline  HistoryLine*            _LineAt(int32 index) const;

private:
                        HistoryLine*            fLines;
                        int32                           fWidth;
                        int32                           fCapacity;
                        int32                           fNextLine;
                        int32                           fSize;
                        uint8*                          fBuffer;
                        int32                           fBufferSize;
                        int32                           fBufferAllocationOffset;
};


inline HistoryLine*
HistoryBuffer::_LineAt(int32 index) const
{
        return &fLines[(fCapacity + fNextLine - index - 1) % fCapacity];
}


inline HistoryLine*
HistoryBuffer::LineAt(int32 index) const
{
        return index >= 0 && index < fSize ? _LineAt(index) : NULL;
}


#endif  // HISTORY_BUFFER_H