// Copyright 2017 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_CSS_CFDE_CSSTEXTBUF_H_
#define XFA_FDE_CSS_CFDE_CSSTEXTBUF_H_

#include "core/fxcrt/cfx_retain_ptr.h"
#include "core/fxcrt/cfx_seekablestreamproxy.h"
#include "core/fxcrt/fx_memory.h"
#include "core/fxcrt/fx_system.h"

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

  void AttachBuffer(const wchar_t* pBuffer, int32_t iBufLen);
  bool EstimateSize(int32_t iAllocSize);
  bool AppendChar(wchar_t wch);

  void Clear() { m_iDatPos = m_iDatLen = 0; }
  void Reset();

  int32_t TrimEnd();

  void Subtract(int32_t iStart, int32_t iLength);
  bool IsEOF() const { return m_iDatPos >= m_iDatLen; }

  wchar_t GetAt(int32_t index) const { return GetBuffer()[index]; }
  wchar_t GetChar() const { return GetBuffer()[m_iDatPos]; }
  wchar_t GetNextChar() const {
    return (m_iDatPos + 1 >= m_iDatLen) ? 0 : GetBuffer()[m_iDatPos + 1];
  }

  void MoveNext() { m_iDatPos++; }

  int32_t GetLength() const { return m_iDatLen; }
  const wchar_t* GetBuffer() const;

 protected:
  bool ExpandBuf(int32_t iDesiredSize);

  bool m_bExtBuf;
  const wchar_t* m_pExtBuffer;
  wchar_t* m_pBuffer;
  int32_t m_iBufLen;
  int32_t m_iDatLen;
  int32_t m_iDatPos;
};

#endif  // XFA_FDE_CSS_CFDE_CSSTEXTBUF_H_