/********************************************************************************
 *                                                                              *
 * This file is part of IfcOpenShell.                                           *
 *                                                                              *
 * IfcOpenShell is free software: you can redistribute it and/or modify         *
 * it under the terms of the Lesser GNU General Public License as published by  *
 * the Free Software Foundation, either version 3.0 of the License, or          *
 * (at your option) any later version.                                          *
 *                                                                              *
 * IfcOpenShell is distributed in the hope that it will be useful,              *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of               *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
 * Lesser GNU General Public License for more details.                          *
 *                                                                              *
 * You should have received a copy of the Lesser GNU General Public License     *
 * along with this program. If not, see <http://www.gnu.org/licenses/>.         *
 *                                                                              *
 ********************************************************************************/

/*********************************************************************************
 *                                                                               *
 * Reads a file and provides functions to access its                             *
 * contents randomly and character by character                                  *
 *                                                                               *
 ********************************************************************************/

#ifndef IFCSPFSTREAM_H
#define IFCSPFSTREAM_H

#include "ifc_parse_api.h"

#include <string>

#ifdef USE_MMAP
#include <boost/iostreams/device/mapped_file.hpp>
#endif

namespace IfcParse {
/// The IfcSpfStream class represents a ISO 10303-21 IFC-SPF file in memory.
/// The file is interpreted as a sequence of tokens which are lazily
/// interpreted only when requested.
class IFC_PARSE_API IfcSpfStream {
  private:
#ifdef USE_MMAP
    boost::iostreams::mapped_file_source mfs;
#endif
    FILE* stream_;
    const char* buffer_;
    unsigned int ptr_;
    unsigned int len_;

  public:
    bool valid;
    bool eof;
    unsigned int size;
#ifdef USE_MMAP
    IfcSpfStream(const std::string& path, bool mmap = false);
#else
    IfcSpfStream(const std::string& path);
#endif
    IfcSpfStream(std::istream& stream, int length);
    IfcSpfStream(void* data, int length);
    ~IfcSpfStream();
    /// Returns the character at the cursor
    char Peek();
    /// Returns the character at specified offset
    char Read(unsigned int offset);
    /// Increment the file cursor and reads new page if necessary
    void Inc();
    void Close();
    /// Moves the file cursor to an arbitrary offset in the file
    void Seek(unsigned int offset);
    /// Returns the cursor position
    unsigned int Tell();

    bool is_eof_at(unsigned int);
    void increment_at(unsigned int&);
    char peek_at(unsigned int);
};
} // namespace IfcParse

#endif