//! @file
//! @author Claes Nasten <pekdon{@}pekdon{.}net
//! @date 2005-06-15
//! @brief Configuration parser source handler.

//
// Copyright (C) 2005 Claes Nasten <pekdon{@}pekdon{.}net>
//
// This program is licensed under the GNU GPL.
// See the LICENSE file for more information.
//

#ifndef _CFG_PARSER_SOURCE_HH_
#define _CFG_PARSER_SOURCE_HH_

#include <string>
#include <cstdio>

extern "C" {
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
}

class CfgParserSource
{
public:
  //! @brief Source type description.
  enum Type {
    SOURCE_FILE, //!< Source from filesystem accesible file.
    SOURCE_COMMAND, //!< Source from command output.
    SOURCE_VIRTUAL //!< Source base type.
  };

  CfgParserSource (const std::string &or_source) :
    m_op_file (NULL), m_or_name(or_source),
    m_type(SOURCE_VIRTUAL), m_i_line (0)
  {
  }
  virtual ~CfgParserSource (void) { }

  //! @brief Gets a character from m_op_file, increments line count if \n.
  inline int getc (void) {
    int i_c = fgetc (m_op_file);
    if (i_c == '\n') {
      ++m_i_line;
    }
    return i_c;
  }

  //! @brief Returns a character to m_op_file, decrements line count if \n.
  inline void ungetc (int i_c)  {
    ::ungetc (i_c, m_op_file);
    if (i_c == '\n') {
      --m_i_line;
    }
  }

  const std::string &get_name(void) { return m_or_name; }
  CfgParserSource::Type get_type(void) { return m_type; }
  int get_line (void) { return m_i_line; }

  virtual bool open (void) throw (std::string&) { return false; }
  virtual void close (void) throw (std::string&) { }

protected:
  FILE *m_op_file;
  const std::string &m_or_name;
  CfgParserSource::Type m_type;
  int m_i_line;
};

class CfgParserSourceFile : public CfgParserSource
{
public:
  CfgParserSourceFile (const std::string &or_source)
    : CfgParserSource (or_source)
  {
    m_type = SOURCE_FILE;
  }
  virtual ~CfgParserSourceFile (void) { }

  virtual bool open (void) throw (std::string&);
  virtual void close (void) throw (std::string&);
};

class CfgParserSourceCommand : public CfgParserSource
{
public:
  CfgParserSourceCommand (const std::string &or_source)
          : CfgParserSource (or_source)
  {
    m_type = SOURCE_COMMAND;
  }
  virtual ~CfgParserSourceCommand (void) { }

  virtual bool open (void) throw (std::string&);
  virtual void close (void) throw (std::string&);

private:
  pid_t m_o_pid;

  struct sigaction m_sigaction; //!< sigaction for restore.
  static unsigned int m_sigaction_counter; //!< Counts open.
};

#endif // _CFG_PARSER_SOURCE_HH_