// src/LineFile.cc
// This file is part of libpbe; see http://svn.chezphil.org/libpbe/
// (C) 2010 Philip Endecott

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// any later version.
//
// This program 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
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

#include "LineFile.hh"

#include "starts_ends_with.hh"


using namespace std;


namespace pbe {


// In order to understand \n, \r\n and \r line-ending conventions, we need 
// an improved getline function.
//
// The following comes from http://stackoverflow.com/questions/6089231/getting-std-ifstream-to-handle-lf-cr-and-crlf

std::istream& getline_crlf(std::istream& is, std::string& t)
{
  t.clear();

  // The characters in the stream are read one-by-one using a std::streambuf.
  // That gives better performance compared with
  // reading them one-by-one using the std::istream.
  // Code that uses streambuf this way must be guarded by a sentry object.
  // The sentry object performs various tasks,
  // such as thread synchronization and updating the stream state.

  std::istream::sentry se(is);
  std::streambuf& sb = *(is.rdbuf());

  while (1) {
    int c = sb.sbumpc();
    switch (c) {
    case '\r':
      c = sb.sgetc();
      if(c == '\n') sb.sbumpc();
      // FALL THROUGH
    case '\n':
      // FALL THROUGH
    case EOF:
      return is;
    default:
      t += static_cast<char>(c);
    }
  }
}


LineFile::LineFile(const char* fn):
  f(fn)
{
  get_next_line();
  linenum_ = 0;
}

LineFile::LineFile(std::string fn):
  f(fn.c_str())
{
  get_next_line();
  linenum_ = 0;
}

void LineFile::get_next_line()
{
  getline_crlf(f,next_line);
  ++linenum_;
  at_eof = f.eof();
}

std::string LineFile::getline()
{
  string s = next_line;
  get_next_line();
  return s;
}

bool LineFile::eof() const
{
  return at_eof;
}


};