/*****************************************************************************
 * RRDtool 1.2.23  Copyright by Tobi Oetiker, 1997-2007
 *****************************************************************************
 * rrd_fetch.c  read date from an rrd to use for further processing
 *****************************************************************************
 * $Id: rrd_fetch.c 1050 2007-05-02 18:06:05Z oetiker $
 * $Log$
 * Revision 1.8  2004/05/18 18:53:03  oetiker
 * big spell checking patch -- slif@bellsouth.net
 *
 * Revision 1.7  2003/11/11 19:46:21  oetiker
 * replaced time_value with rrd_time_value as MacOS X introduced a struct of that name in their standard headers
 *
 * Revision 1.6  2003/01/16 23:27:54  oetiker
 * fix border condition in rra selection of rrd_fetch
 * -- Stanislav Sinyagin <ssinyagin@yahoo.com>
 *
 * Revision 1.5  2002/06/23 22:29:40  alex
 * Added "step=1800" and such to "DEF"
 * Cleaned some of the signed vs. unsigned problems
 *
 * Revision 1.4  2002/02/01 20:34:49  oetiker
 * fixed version number and date/time
 *
 * Revision 1.3  2001/12/24 06:51:49  alex
 * A patch of size 44Kbytes... in short:
 *
 * Found and repaired the off-by-one error in rrd_fetch_fn().
 * As a result I had to remove the hacks in rrd_fetch_fn(),
 * rrd_tool.c, vdef_calc(), data_calc(), data_proc() and
 * reduce_data().  There may be other places which I didn't
 * find so be careful.
 *
 * Enhanced debugging in rrd_fetch_fn(), it shows the RRA selection
 * process.
 *
 * Added the ability to print VDEF timestamps.  At the moment it
 * is a hack, I needed it now to fix the off-by-one error.
 * If the format string is "%c" (and nothing else!), the time
 * will be printed by both ctime() and as a long int.
 *
 * Moved some code around (slightly altering it) from rrd_graph()
 *   initializing     now in rrd_graph_init()
 *   options parsing  now in rrd_graph_options()
 *   script parsing   now in rrd_graph_script()
 *
 * Revision 1.2  2001/12/17 12:48:43  oetiker
 * fix overflow error ...
 *
 * Revision 1.1.1.1  2001/02/25 22:25:05  oetiker
 * checkin
 *
 *****************************************************************************/

#include "rrd_tool.h"

#include "rrd_is_thread_safe.h"
/*#define DEBUG*/

int
rrd_fetch(int argc, 
	  char **argv,
	  time_t         *start,
	  time_t         *end,       /* which time frame do you want ?
				      * will be changed to represent reality */
	  unsigned long  *step,      /* which stepsize do you want? 
				      * will be changed to represent reality */
	  unsigned long  *ds_cnt,    /* number of data sources in file */
	  char           ***ds_namv,   /* names of data sources */
	  rrd_value_t    **data)     /* two dimensional array containing the data */
{


    long     step_tmp =1;
    time_t   start_tmp=0, end_tmp=0;
    const char *cf;

    struct rrd_time_value start_tv, end_tv;
    char     *parsetime_error = NULL;
    optind = 0; opterr = 0;  /* initialize getopt */

    /* init start and end time */
    parsetime("end-24h", &start_tv);
    parsetime("now", &end_tv);

    while (1){
	static struct option long_options[] =
	{
	    {"resolution",      required_argument, 0, 'r'},
	    {"start",      required_argument, 0, 's'},
	    {"end",      required_argument, 0, 'e'},
	    {0,0,0,0}
	};
	int option_index = 0;
	int opt;
	opt = getopt_long(argc, argv, "r:s:e:", 
			  long_options, &option_index);

	if (opt == EOF)
	    break;

	switch(opt) {
	case 's':
            if ((parsetime_error = parsetime(optarg, &start_tv))) {
                rrd_set_error( "start time: %s", parsetime_error );
                return -1;
	    }
	    break;
	case 'e':
            if ((parsetime_error = parsetime(optarg, &end_tv))) {
                rrd_set_error( "end time: %s", parsetime_error );
                return -1;
	    }
	    break;
	case 'r':
	    step_tmp = atol(optarg);
	    break;
	case '?':
	    rrd_set_error("unknown option '-%c'",optopt);
	    return(-1);
	}
    }

    
    if (proc_start_end(&start_tv,&end_tv,&start_tmp,&end_tmp) == -1){
	return -1;
    }  

    
    if (start_tmp < 3600*24*365*10){
	rrd_set_error("the first entry to fetch should be after 1980");
	return(-1);
    }
    
    if (end_tmp < start_tmp) {
	rrd_set_error("start (%ld) should be less than end (%ld)", start_tmp, end_tmp);
	return(-1);
    }
    
    *start = start_tmp;
    *end = end_tmp;

    if (step_tmp < 1) {
	rrd_set_error("step must be >= 1 second");
	return -1;
    }
    *step = step_tmp;
    
    if (optind + 1 >= argc){
	rrd_set_error("not enough arguments");
	return -1;
    }

    cf = argv[optind+1];

    if (rrd_fetch_r(argv[optind],cf,start,end,step,ds_cnt,ds_namv,data) == -1)
	return(-1);
    return (0);
}

int
rrd_fetch_r(
    const char           *filename,  /* name of the rrd */
    const char           *cf,        /* which consolidation function ?*/
    time_t         *start,
    time_t         *end,       /* which time frame do you want ?
                                * will be changed to represent reality */
    unsigned long  *step,      /* which stepsize do you want? 
                                * will be changed to represent reality */
    unsigned long  *ds_cnt,    /* number of data sources in file */
    char           ***ds_namv, /* names of data_sources */
    rrd_value_t    **data)     /* two dimensional array containing the data */
{
    enum     cf_en cf_idx;

    if ((int)(cf_idx=cf_conv(cf)) == -1 ){
        return -1;
    }

    return (rrd_fetch_fn(filename,cf_idx,start,end,step,ds_cnt,ds_namv,data));
}

int
rrd_fetch_fn(
    const char     *filename,  /* name of the rrd */
    enum cf_en     cf_idx,         /* which consolidation function ?*/
    time_t         *start,
    time_t         *end,       /* which time frame do you want ?
			        * will be changed to represent reality */
    unsigned long  *step,      /* which stepsize do you want? 
				* will be changed to represent reality */
    unsigned long  *ds_cnt,    /* number of data sources in file */
    char           ***ds_namv,   /* names of data_sources */
    rrd_value_t    **data)     /* two dimensional array containing the data */
{
    long           i,ii;
    FILE           *in_file;
    time_t         cal_start,cal_end, rra_start_time,rra_end_time;
    long  best_full_rra=0, best_part_rra=0, chosen_rra=0, rra_pointer=0;
    long  best_full_step_diff=0, best_part_step_diff=0, tmp_step_diff=0, tmp_match=0, best_match=0;
    long  full_match, rra_base;
    long           start_offset, end_offset;
    int            first_full = 1;
    int            first_part = 1;
    rrd_t     rrd;
    rrd_value_t    *data_ptr;
    unsigned long  rows;

#ifdef DEBUG
fprintf(stderr,"Entered rrd_fetch_fn() searching for the best match\n");
fprintf(stderr,"Looking for: start %10lu end %10lu step %5lu\n",
						*start,*end,*step);
#endif

    if(rrd_open(filename,&in_file,&rrd, RRD_READONLY)==-1)
	return(-1);
    
    /* when was the really last update of this file ? */

    if (((*ds_namv) = (char **) malloc(rrd.stat_head->ds_cnt * sizeof(char*)))==NULL){
	rrd_set_error("malloc fetch ds_namv array");
	rrd_free(&rrd);
	fclose(in_file);
	return(-1);
    }
    
    for(i=0;(unsigned long)i<rrd.stat_head->ds_cnt;i++){
	if ((((*ds_namv)[i]) = malloc(sizeof(char) * DS_NAM_SIZE))==NULL){
	    rrd_set_error("malloc fetch ds_namv entry");
	    rrd_free(&rrd);
	    free(*ds_namv);
	    fclose(in_file);
	    return(-1);
	}
	strncpy((*ds_namv)[i],rrd.ds_def[i].ds_nam,DS_NAM_SIZE-1);
	(*ds_namv)[i][DS_NAM_SIZE-1]='\0';

    }
    
    /* find the rra which best matches the requirements */
    for(i=0;(unsigned)i<rrd.stat_head->rra_cnt;i++){
	if(cf_conv(rrd.rra_def[i].cf_nam) == cf_idx){
	    
	    cal_end = (rrd.live_head->last_up - (rrd.live_head->last_up 
			  % (rrd.rra_def[i].pdp_cnt 
			     * rrd.stat_head->pdp_step)));
	    cal_start = (cal_end 
			 - (rrd.rra_def[i].pdp_cnt 
			    * rrd.rra_def[i].row_cnt
			    * rrd.stat_head->pdp_step));

	    full_match = *end -*start;
#ifdef DEBUG
fprintf(stderr,"Considering: start %10lu end %10lu step %5lu ",
							cal_start,cal_end,
			rrd.stat_head->pdp_step * rrd.rra_def[i].pdp_cnt);
#endif
 	    /* we need step difference in either full or partial case */
 	    tmp_step_diff = labs(*step - (rrd.stat_head->pdp_step
					   * rrd.rra_def[i].pdp_cnt));
	    /* best full match */
	    if(cal_end >= *end 
	       && cal_start <= *start){
		if (first_full || (tmp_step_diff < best_full_step_diff)){
		    first_full=0;
		    best_full_step_diff = tmp_step_diff;
		    best_full_rra=i;
#ifdef DEBUG
fprintf(stderr,"best full match so far\n");
#endif
		} else {
#ifdef DEBUG
fprintf(stderr,"full match, not best\n");
#endif
		}
		
	    } else {
		/* best partial match */
		tmp_match = full_match;
		if (cal_start>*start)
		    tmp_match -= (cal_start-*start);
		if (cal_end<*end)
		    tmp_match -= (*end-cal_end);		
		if (first_part ||
                    (best_match < tmp_match) ||
                    (best_match == tmp_match && 
                     tmp_step_diff < best_part_step_diff)){ 
#ifdef DEBUG
fprintf(stderr,"best partial so far\n");
#endif
		    first_part=0;
		    best_match = tmp_match;
		    best_part_step_diff = tmp_step_diff;
		    best_part_rra =i;
		} else {
#ifdef DEBUG
fprintf(stderr,"partial match, not best\n");
#endif
		}
	    }
	}
    }

    /* lets see how the matching went. */
    if (first_full==0)
	chosen_rra = best_full_rra;
    else if (first_part==0)
	chosen_rra = best_part_rra;
    else {
	rrd_set_error("the RRD does not contain an RRA matching the chosen CF");
	rrd_free(&rrd);
	fclose(in_file);
	return(-1);
    }
	
    /* set the wish parameters to their real values */
    *step = rrd.stat_head->pdp_step * rrd.rra_def[chosen_rra].pdp_cnt;
    *start -= (*start % *step);
    *end += (*step - *end % *step);
    rows = (*end - *start) / *step + 1;

#ifdef DEBUG
    fprintf(stderr,"We found:    start %10lu end %10lu step %5lu rows  %lu\n",
						*start,*end,*step,rows);
#endif

/* Start and end are now multiples of the step size.  The amount of
** steps we want is (end-start)/step and *not* an extra one.
** Reasoning:  if step is s and we want to graph from t to t+s,
** we need exactly ((t+s)-t)/s rows.  The row to collect from the
** database is the one with time stamp (t+s) which means t to t+s.
*/
    *ds_cnt =   rrd.stat_head->ds_cnt; 
    if (((*data) = malloc(*ds_cnt * rows * sizeof(rrd_value_t)))==NULL){
	rrd_set_error("malloc fetch data area");
	for (i=0;(unsigned long)i<*ds_cnt;i++)
	      free((*ds_namv)[i]);
	free(*ds_namv);
	rrd_free(&rrd);
	fclose(in_file);
	return(-1);
    }
    
    data_ptr=(*data);
    
    /* find base address of rra */
    rra_base=ftell(in_file);
    for(i=0;i<chosen_rra;i++)
	rra_base += ( *ds_cnt
		      * rrd.rra_def[i].row_cnt
		      * sizeof(rrd_value_t));

    /* find start and end offset */
    rra_end_time = (rrd.live_head->last_up 
		    - (rrd.live_head->last_up % *step));
    rra_start_time = (rra_end_time
		 - ( *step * (rrd.rra_def[chosen_rra].row_cnt-1)));
    /* here's an error by one if we don't be careful */
    start_offset =(long)(*start + *step - rra_start_time) / (long)*step;
    end_offset = (long)(rra_end_time - *end ) / (long)*step; 
#ifdef DEBUG
    fprintf(stderr,"rra_start %lu, rra_end %lu, start_off %li, end_off %li\n",
	    rra_start_time,rra_end_time,start_offset,end_offset);
#endif

    /* fill the gap at the start if needs be */

    if (start_offset <= 0)
	rra_pointer = rrd.rra_ptr[chosen_rra].cur_row+1;
    else 
	rra_pointer = rrd.rra_ptr[chosen_rra].cur_row+1+start_offset;
    
    if(fseek(in_file,(rra_base 
		   + (rra_pointer
		      * *ds_cnt
		      * sizeof(rrd_value_t))),SEEK_SET) != 0){
	rrd_set_error("seek error in RRA");
	for (i=0;(unsigned)i<*ds_cnt;i++)
	      free((*ds_namv)[i]);
	free(*ds_namv);
	rrd_free(&rrd);
	free(*data);
	*data = NULL;
	fclose(in_file);
	return(-1);

    }
#ifdef DEBUG
    fprintf(stderr,"First Seek: rra_base %lu rra_pointer %lu\n",
	    rra_base, rra_pointer);
#endif
    /* step trough the array */

    for (i=start_offset;
	 i< (signed)rrd.rra_def[chosen_rra].row_cnt - end_offset;
	 i++){
	/* no valid data yet */
	if (i<0) {
#ifdef DEBUG
	    fprintf(stderr,"pre fetch %li -- ",i);
#endif
	    for(ii=0;(unsigned)ii<*ds_cnt;ii++){
		*(data_ptr++) = DNAN;
#ifdef DEBUG
		fprintf(stderr,"%10.2f ",*(data_ptr-1));
#endif
	    }
	} 
	/* past the valid data area */
	else if (i >= (signed)rrd.rra_def[chosen_rra].row_cnt) {
#ifdef DEBUG
	    fprintf(stderr,"post fetch %li -- ",i);
#endif
	    for(ii=0;(unsigned)ii<*ds_cnt;ii++){
		*(data_ptr++) = DNAN;
#ifdef DEBUG
		fprintf(stderr,"%10.2f ",*(data_ptr-1));
#endif
	    }
	} else {
	    /* OK we are inside the valid area but the pointer has to 
	     * be wrapped*/
	    if (rra_pointer >= (signed)rrd.rra_def[chosen_rra].row_cnt) {
		rra_pointer -= rrd.rra_def[chosen_rra].row_cnt;
		if(fseek(in_file,(rra_base+rra_pointer
			       * *ds_cnt
			       * sizeof(rrd_value_t)),SEEK_SET) != 0){
		    rrd_set_error("wrap seek in RRA did fail");
		    for (ii=0;(unsigned)ii<*ds_cnt;ii++)
			free((*ds_namv)[ii]);
		    free(*ds_namv);
		    rrd_free(&rrd);
		    free(*data);
		    *data = NULL;
		    fclose(in_file);
		    return(-1);
		}
#ifdef DEBUG
		fprintf(stderr,"wrap seek ...\n");
#endif	    
	    }
	    
	    if(fread(data_ptr,
		     sizeof(rrd_value_t),
		     *ds_cnt,in_file) != rrd.stat_head->ds_cnt){
		rrd_set_error("fetching cdp from rra");
		for (ii=0;(unsigned)ii<*ds_cnt;ii++)
		    free((*ds_namv)[ii]);
		free(*ds_namv);
		rrd_free(&rrd);
		free(*data);
		*data = NULL;
		fclose(in_file);
		return(-1);
	    }
#ifdef DEBUG
	    fprintf(stderr,"post fetch %li -- ",i);
	    for(ii=0;ii<*ds_cnt;ii++)
		fprintf(stderr,"%10.2f ",*(data_ptr+ii));
#endif
	    data_ptr += *ds_cnt;
	    rra_pointer ++;
	}
#ifdef DEBUG
	    fprintf(stderr,"\n");
#endif	    
	
    }
    rrd_free(&rrd);
    fclose(in_file);
    return(0);
}