/* SDB - import/export command routines */

#include <stdio.h>
#include "sdbio.h"

extern int dbv_token;
extern char dbv_tstring[];
extern int dbv_tvalue;

/* db_import - import tuples from a file */
int *db_import(fmt,a1,a2,a3,a4,a5,a6,a7,a8,a9)
  char *fmt;
{
    struct scan *sptr;
    struct attribute *aptr;
    char fname[STRINGMAX+1],avalue[STRINGMAX+1];
    int tcnt,astart,i,eofile;
    FILE *fp;

    /* check for a command line */
    if (fmt != NULL)
    	db_scan(fmt,a1,a2,a3,a4,a5,a6,a7,a8,a9);

    /* checks for "<filename> into <relation-name>" */
    if (db_ntoken() == ID)
    	strcat(dbv_tstring,".dat");
    else if (dbv_token != STRING)
    	return (db_ferror(SYNTAX));
    strcpy(fname,dbv_tstring);
    if (db_ntoken() != INTO)
    	return (db_ferror(SYNTAX));
    if (db_ntoken() != ID)
	return (db_ferror(SYNTAX));

    /* open the relation */
    if ((sptr = db_ropen(dbv_tstring)) == NULL)
	return (FALSE);

    /* open the input file */
    if ((fp = fopen(fname,"r")) == NULL)
    	return (db_ferror(INPFNF));

    /* import tuples */
    eofile = FALSE;
    for (tcnt = 0; ; tcnt++) {

    	/* get attribute values */
    	astart = 1;
    	for (i = 0; i < NATTRS; i++) {

    	    /* get a pointer to the current attribute */
	    aptr = &sptr->sc_relation->rl_header.hd_attrs[i];

	    /* check for the last attribute */
	    if (aptr->at_name[0] == 0)
    		break;

    	    /* input the tuple */
    	    if (fgets(avalue,STRINGMAX,fp) == 0) {
    		eofile = TRUE;
    		break;
    	    }
    	    avalue[strlen(avalue)-1] = EOS;

	    /* store the attribute value */
	    db_aput(aptr,&sptr->sc_tuple[astart],avalue);

    	    /* update the attribute start */
    	    astart += aptr->at_size;
    	}

    	/* store the new tuple */
    	if (!eofile) {
    	    if (!db_rstore(sptr)) {
    		db_rclose(sptr);
    		return (FALSE);
    	    }
    	}
    	else
    	    break;
    }

    /* close the relation */
    db_rclose(sptr);

    /* close the input file */
    fclose(fp);

    /* check number of tuples imported */
    if (tcnt != 0) {

	/* print tuple count */
    	printf("[ %d imported ]\n",tcnt);
    }
    else
	printf("[ none imported ]\n");

    /* return successfully */
    return (TRUE);
}

/* db_export - export tuples to a file */
int *db_export(fmt,a1,a2,a3,a4,a5,a6,a7,a8,a9)
  char *fmt;
{
    struct scan *sptr;
    struct attribute *aptr;
    char rname[STRINGMAX+1],avalue[STRINGMAX+1];
    int tcnt,astart,i;
    FILE *fp;

    /* check for a command line */
    if (fmt != NULL)
    	db_scan(fmt,a1,a2,a3,a4,a5,a6,a7,a8,a9);

    /* checks for "<relation-name> [ into <filename> ]" */
    if (db_ntoken() != ID)
	return (db_ferror(SYNTAX));
    strcpy(rname,dbv_tstring);
    if (!db_to(&fp,".dat"))
    	return (FALSE);

    /* open the relation */
    if ((sptr = db_ropen(rname)) == NULL)
	return (FALSE);

    /* export tuples */
    for (tcnt = 0; db_rfetch(sptr); tcnt++) {

    	/* get attribute values */
    	astart = 1;
    	for (i = 0; i < NATTRS; i++) {

    	    /* get a pointer to the current attribute */
	    aptr = &sptr->sc_relation->rl_header.hd_attrs[i];

	    /* check for the last attribute */
	    if (aptr->at_name[0] == 0)
		break;

	    /* get the attribute value */
	    db_aget(aptr,&sptr->sc_tuple[astart],avalue);

    	    /* output the tuple */
    	    fprintf(fp,"%s\n",avalue); 

    	    /* update the attribute start */
    	    astart += aptr->at_size;
    	}
    }

    /* close the relation */
    db_rclose(sptr);

    /* close the output file */
    if (fp != stdout)
    	fclose(fp);

    /* check number of tuples exported */
    if (tcnt != 0) {

	/* print tuple count */
    	printf("[ %d exported ]\n",tcnt);
    }
    else
	printf("[ none exported ]\n");

    /* return successfully */
    return (TRUE);
}

/* db_squeeze - squeeze deleted tuples from a relation file */
int *db_squeeze(fmt,a1,a2,a3,a4,a5,a6,a7,a8,a9)
  char *fmt;
{
    struct scan *sptr;

    /* check for a command line */
    if (fmt != NULL)
    	db_scan(fmt,a1,a2,a3,a4,a5,a6,a7,a8,a9);

    /* checks for "<relation-name>" */
    if (db_ntoken() != ID)
	return (db_ferror(SYNTAX));

    /* open the relation */
    if ((sptr = db_ropen(dbv_tstring)) == NULL)
	return (FALSE);

    /* compress the relation file */
    if (!db_rcompress(sptr)) {
	db_rclose(sptr);
	return (FALSE);
    }

    /* close the relation */
    db_rclose(sptr);

    /* return successfully */
    return (TRUE);
}

/* db_extract - extract a relation definition */
int *db_extract(fmt,a1,a2,a3,a4,a5,a6,a7,a8,a9)
  char *fmt;
{
    struct scan *sptr;
    struct attribute *aptr;
    char rname[STRINGMAX+1],aname[ANSIZE+1],*atype;
    int i;
    FILE *fp;

    /* check for a command line */
    if (fmt != NULL)
    	db_scan(fmt,a1,a2,a3,a4,a5,a6,a7,a8,a9);

    /* checks for "<relation-name> [ into <filename> ]" */
    if (db_ntoken() != ID)
	return (db_ferror(SYNTAX));
    strcpy(rname,dbv_tstring);
    if (!db_to(&fp,".def"))
    	return (FALSE);

    /* open the relation */
    if ((sptr = db_ropen(rname)) == NULL)
	return (FALSE);

    /* output the relation definition */
    fprintf(fp,"create %s (\n",rname);

    /* get attribute values */
    for (i = 0; i < NATTRS; i++) {

        /* get a pointer to the current attribute */
    	aptr = &sptr->sc_relation->rl_header.hd_attrs[i];

	/* check for the last attribute */
	if (aptr->at_name[0] == 0)
	    break;

	/* get the attribute name */
	strncpy(aname,aptr->at_name,ANSIZE); aname[ANSIZE] = 0;

    	/* determine the attribute type */
    	switch (aptr->at_type) {
    	case TCHAR:
    		atype = "char";
    		break;
    	case TNUM:
    		atype = "num";
    		break;
    	default:
    		atype = "<error>";
    		break;
    	}

    	/* output the attribute definition */
    	if (strlen(aname) < 8)
    	    fprintf(fp,"\t%s\t\t%s\t%d\n",aname,atype,aptr->at_size);
    	else
    	    fprintf(fp,"\t%s\t%s\t%d\n",aname,atype,aptr->at_size);
    }

    /* output the relation size */
    fprintf(fp,") %d\n",sptr->sc_relation->rl_tmax);

    /* close the relation */
    db_rclose(sptr);

    /* close the output file */
    if (fp != stdout)
    	fclose(fp);

    /* return successfully */
    return (TRUE);
}