/* Copyright (c) 2005-2017 Jay Berkenbilt
 *
 * This file is part of qpdf.  This software may be distributed under
 * the terms of version 2 of the Artistic License which may be found
 * in the source distribution.  It is provided "as is" without express
 * or implied warranty.
 */

#ifndef __QPDF_INPUTSOURCE_HH__
#define __QPDF_INPUTSOURCE_HH__

#include <qpdf/DLL.h>
#include <qpdf/Types.h>
#include <stdio.h>
#include <string>

class InputSource
{
  public:
    QPDF_DLL
    InputSource() :
        last_offset(0)
    {
    }
    QPDF_DLL
    virtual ~InputSource()
    {
    }

    class Finder
    {
      public:
        Finder()
        {
        }
        virtual ~Finder()
        {
        }

        virtual bool check() = 0;
    };

    QPDF_DLL
    void setLastOffset(qpdf_offset_t);
    QPDF_DLL
    qpdf_offset_t getLastOffset() const;
    QPDF_DLL
    std::string readLine(size_t max_line_length);

    // Find first or last occurrence of a sequence of characters
    // starting within the range defined by offset and len such that,
    // when the input source is positioned at the beginning of that
    // sequence, finder.check() returns true. If len is 0, the search
    // proceeds until EOF. If a qualifying pattern these methods
    // return true and leave the input source positioned wherever
    // check() left it at the end of the matching pattern.
    QPDF_DLL
    bool findFirst(char const* start_chars,
                   qpdf_offset_t offset, size_t len,
                   Finder& finder);
    QPDF_DLL
    bool findLast(char const* start_chars,
                  qpdf_offset_t offset, size_t len,
                  Finder& finder);

    virtual qpdf_offset_t findAndSkipNextEOL() = 0;
    virtual std::string const& getName() const = 0;
    virtual qpdf_offset_t tell() = 0;
    virtual void seek(qpdf_offset_t offset, int whence) = 0;
    virtual void rewind() = 0;
    virtual size_t read(char* buffer, size_t length) = 0;
    virtual void unreadCh(char ch) = 0;

  protected:
    qpdf_offset_t last_offset;
};

#endif // __QPDF_INPUTSOURCE_HH__