#ident "$URL: svn://elmer/devel/SVN/SDDAS/trunk/libdB/CloseDbf.c $ %D% SwRI"

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "dbf.h"

/********************
 ** >FILE: CloseDbf.c
 ********************/

/**********************************************
 ** Function:  int UpdateHeader(dbfrecord_t *D)
 **
 **    dbfrecord_t *d handle    pointer to database structure
 **
 ** Description:
 **    reset the header information and write it out to the database file
 **
 ** Return Values:
 **    * FAILURE - dbf_code set to actual error
 **    * SUCCESS - the routine completed without error
 **
 *****************
 *****************/

dbRet_t UpdateHeader(dbfRecord_t *D)
{
   struct tm *mytm;
   struct stat buf;
   off_t offset;
   int r;

   r = (int) D->NumRecs;

   /*
    | get the date of the file for the header information
    */
   (void)fstat(D->dFile, &buf);
   mytm = localtime(&buf.st_mtime);

   /*
    | be sure to write it out the date of the file in the correct database file
    | type format
    */
   if (D->HeadProlog[0] == DB2File)
   {
      D->HeadProlog[5] = mytm->tm_year; /* Year           */
      D->HeadProlog[3] = mytm->tm_mon;  /* Month of year  */
      D->HeadProlog[4] = mytm->tm_mday; /* Day of month   */
      D->HeadProlog[2] = r/256;
      r -= D->HeadProlog[5]*2560;
      D->HeadProlog[1] = r;
   }
   else     
   {
      D->HeadProlog[1] = mytm->tm_year; /* Year           */
      D->HeadProlog[2] = mytm->tm_mon;  /* Month of year  */
      D->HeadProlog[3] = mytm->tm_mday; /* Day of month   */

      D->HeadProlog[7] = (char) (r/16777216);
      r -= ((unsigned char)D->HeadProlog[7] * 16777216);
      D->HeadProlog[6] = (char) (r/65536);
      r -= ((unsigned char)D->HeadProlog[6] * 65536);
      D->HeadProlog[5] = (char) (r/256);
      r -= ((unsigned char)D->HeadProlog[5] * 256);
      D->HeadProlog[4] = (char)r;
   }

   /*
    | the header information goes at the beginning of the file, lseek to it.
    | If lseeking to the offset position does not retuen the offset, and error
    | has occured, return an lseek error.
    */
   offset = 0;
   if (lseek(D->dFile, offset, SEEK_SET) < offset)
   {
      dbf_code = LSEEK_ERROR;
      sprintf(msg, "'%s'", D->FileName);
      return FAILURE;
   }
   
   /*
    | if there is no problem in seeking to the beginning of the file write
    | out the header information
    */
   if (write(D->dFile, D->HeadProlog, 8) < 8)
   {
      dbf_code = WRITE_ERROR;
      sprintf(msg, "'%s'", D->FileName);
      return FAILURE;
   }

   /*
    | reset the status of the header info indicating that it matches the info
    | in the file
    */
   D->hStatus = NotUpdated;

   return SUCCESS;
}
             

/**************************************
 ** Function:  int CloseDbf(int handle)
 **
 **    int handle    database handle
 **
 ** Description:
 **    This subroutine closes the database file associated with the database
 ** structure D.  If the current record has been updated then it is written
 ** to the database file.  Once the database file is closed, all the
 ** parameters in the database structure is reset, and any pointers are
 ** freed.
 **
 ** Return Values:
 **    * FAILURE - dbf_code set to actual error
 **    * SUCCESS - the routine completed without error
 **
 *****************
 *****************/

dbRet_t CloseDbf(SDDAS_INT handle)
{
   dbfRecord_t *D;

   if ((D = GetOldDbfHandle(handle)) == NULL)
      return FAILURE;

   /*
    | update the database file if needed
    */ 
   if (D->rStatus == Updated)
   {
      if (PutDbfRecord(handle, D->CurRec) != SUCCESS)
      {
         return FAILURE;
      }
   }
   if (D->hStatus == Updated)
   {
      if (UpdateHeader(D) != SUCCESS)
      {
         return FAILURE;
      }
   }

   /*
    | close the database file and set the appropiate variables
    */
   (void)close(D->dFile);
   D->dFile   = -1;
   D->hStatus = NotOpen;

   /*
    | free any memory associated with the database structure
    */
   free((char *)D->CurRecord);
   D->CurRecord = NULL;

   free((char *)D->Fields);
   D->Fields = NULL;

   if (D == dbfRecords)
      dbfRecords = D->next;

   else
   {
      dbfRecord_t *d;

      for (d = dbfRecords ; d->next != NULL; d = d->next)
         if (d->next == D)
            break;

      d->next = D->next;
   }
   free(D);

   return SUCCESS;
}