/*
    Class declaration for the Seq_IO class
	The Seq_IO class can be used independently or as part of the MiniDB project.

    Copyright (C) 1998  Hossein Hakimzadeh

	Comments and bug fixes can be sent to hhakimza@iusb.edu
	
	This code is dedicated to my former student Willard.  He was a
	hard working student and a very decent individual.  I miss his stories.

    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 3 of the License, or
    (at your option) 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, see <http://www.gnu.org/licenses/>.

*/

#ifndef SEQ_IO_H
#define SEQ_IO_H

#define CLOSED				0
#define OPEN_FOR_READ		1
#define OPEN_FOR_WRITE		2

#define FALSE	0
#define TRUE	1

#define ON		1
#define OFF		0
//-----------------------------------------------------------------
#include <fstream>


class Seq_IO
{
	char    FileName[256];                          // *.dat
	fstream Seqfp;                                  // Pointer to file class
	int     State;                                  // File state (OPEN for READ  WRITE, APPEND, or CLOSED)
	int     Verbose;                                // Verbose flag (ON / OFF)

  public:

	Seq_IO(char *filename);                         // Constructor
	~Seq_IO();                                      // Destructor

	void EraseFile(void);                           // Erase the file
	int  OpenForWrite(void);                        // If file does not exist create it, if it does, erase it.
	int  OpenForAppend(void);                       // If file does not exist create it, if it does, place the file point at the end of the file.
	int  OpenForRead(void);                         // Return 1 if successful
	int  CloseFile();                               // if the file is open, close it, otherwise return -1

	int  WriteData(char *a_record);                 // Write/Append a record
	int  ReadData(char *a_record,  char rec_sep);   // Read record (starting current file location, until a record separator is found)
	int  ReadData(char *a_record, 
                  unsigned long record_location,
                  char rec_sep);                    // Read a record (until a record separator is found)

	unsigned long GetCurrentFileLocation(void);     // if the file is open, get the current location
	unsigned long SetCurrentFileLocation(
                  unsigned long location);          // if the file is open, set the file pointer to location

	unsigned long FileSize(void);                   // if the file is open, return the last location in the file
};

#endif