// Copyright 2014 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#ifndef XFA_FDE_CFDE_TXTEDTBUF_H_
#define XFA_FDE_CFDE_TXTEDTBUF_H_

#include <memory>

#include "core/fxcrt/fx_basic.h"
#include "core/fxcrt/fx_system.h"

class IFX_MemoryAllocator;
class IFX_Pause;

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

  int32_t GetChunkSize() const;
  int32_t GetTextLength() const;
  void SetText(const CFX_WideString& wsText);
  CFX_WideString GetText() const;
  FX_WCHAR GetCharByIndex(int32_t nIndex) const;
  CFX_WideString GetRange(int32_t nBegin, int32_t nCount = -1) const;

  void Insert(int32_t nPos, const FX_WCHAR* lpText, int32_t nLength = 1);
  void Delete(int32_t nIndex, int32_t nLength = 1);
  void Clear(bool bRelease = true);

  bool Optimize(IFX_Pause* pPause = nullptr);

 private:
  friend class CFDE_TxtEdtBufIter;

  struct FDE_CHUNKHEADER {
    int32_t nUsed;
    FX_WCHAR wChars[1];
  };

  struct FDE_CHUNKPLACE {
    int32_t nChunkIndex;
    int32_t nCharIndex;
  };

  void ResetChunkBuffer(int32_t nDefChunkCount, int32_t nChunkSize);
  int32_t CP2Index(const FDE_CHUNKPLACE& cp) const;
  void Index2CP(int32_t nIndex, FDE_CHUNKPLACE& cp) const;

  int32_t m_nChunkSize;

  int32_t m_nTotal;
  bool m_bChanged;
  CFX_ArrayTemplate<FDE_CHUNKHEADER*> m_Chunks;
  std::unique_ptr<IFX_MemoryAllocator> m_pAllocator;
};

#endif  // XFA_FDE_CFDE_TXTEDTBUF_H_