/* bar.c 
 *
 * function defined:
 *
 * bar(dist_stats,colors) 
 *
 * struct stat_list *dist_stats          - linked list of statistics
 * struct Colors *colors                 - map colors
 * 
 * PURPOSE: To draw a bar-chart representing the histogram
 * statistics in the linked list dist_stats.  
 *
 * NOTES: 
 *
 * 1) see dhist.h for a decalaration of the structure stat_list.  
 * 2) see bar.h for normalized coordinates of the different parts
 *    of the bar-chart, like the origin of the chart, the label
 *    positions, etc.
 *
 *
 * Dave Johnson
 * DBA Systems, Inc.
 * 10560 Arrowhead Drive
 * Fairfax, Virginia 22030
 *
 */

#include <string.h>
#include <grass/display.h>
#include <grass/raster.h>
#include "bar.h"

int bar (
    struct stat_list *dist_stats,  /* list of distribution statistics */
    struct Colors *colors
)
{
	struct stat_node *ptr;
	int draw=YES;
	long int bar_height;     /* height, in pixels, of a histogram bar */
	CELL bar_color;      /* color/category number of a histogram bar */
	DCELL dmax, range_dmin, range_dmax, dmin, dval;
	long int max_tics;       /* maximum tics allowed on an axis */
	long int xoffset;        /* offset for x-axis */
	long int yoffset;        /* offset for y-axis */
	long int cat_incr = 1;
	long int stat_incr = 1;
	long int stat_start;
	long int stat_finis;
	int text_height;
	int text_width;
	long int i, j;
	long int num_cats = 0;
	long int num_stats = 0;
	long int tic_every;       /* spacing, in units of category value, of tics */

	long int tic_unit;
	int t, b, l, r;
	int tt, tb, tl, tr;
	int x_line[3];            /* for border of histogram */
	int y_line[3];
	int x_box[5];             /* for histogram bar coordinates */
	int y_box[5];
	double height, width;
	double xscale;            /* scaling factors */
	double yscale;
	char xlabel[1024];
	char ylabel[1024];
	char txt[1024];
	char tic_name[80];
	extern int stash_away();

	/* get coordinates of current screen window, in pixels */
	D_get_screen_window(&t, &b, &l, &r) ;
	R_set_window(t, b, l, r) ;

	/* create axis lines, to be drawn later */
	height = b-t;
	width = r-l;
	x_line[0] = x_line[1] = l+(int)(ORIGIN_X*width);
	x_line[2] = l+(int)(XAXIS_END*width);
	y_line[0] = b-(int)(YAXIS_END*height);
	y_line[1] = y_line[2] = b-(int)(ORIGIN_Y*height);

	/* figure scaling factors and offsets */
	num_cats = dist_stats->maxcat - dist_stats->mincat + 1;

	if(nodata)
	{
	    num_cats++;
	    dist_stats->mincat--;
        }
	xscale = ((double)(x_line[2]-x_line[1])/((double)num_cats));
	yscale = ((double)(y_line[1]-y_line[0]))/dist_stats->maxstat;
	if (num_cats >= x_line[2]-x_line[1])
		xoffset = (long int)x_line[1];
	else
		xoffset = (long int)x_line[0]+0.5*xscale;  /* boxes need extra space */
	yoffset = (double)(y_line[1]);

	/* figure tic_every and tic_units for the x-axis of the bar-chart.
 * tic_every tells how often to place a tic-number.  tic_unit tells
 * the unit to use in expressing tic-numbers.
 */
	if (xscale < XTIC_DIST)
	{
		max_tics = (x_line[2]-x_line[1])/XTIC_DIST;
		if(nodata) max_tics--;
		i=0;
		if(is_fp)
		{
		   G_get_fp_range_min_max (&fp_range, &range_dmin, &range_dmax);
		   if(G_is_d_null_value(&range_dmin) || G_is_d_null_value(&range_dmax))
		        G_fatal_error("Floating point data range is empty");

                   while((range_dmax - range_dmin)/tics[i].every > max_tics)
		       i++;
                }
		else
		{
		   while ((num_cats/tics[i].every) > max_tics)
			i++;
                }
		tic_every = tics[i].every;
		tic_unit = tics[i].unit;
		strcpy(tic_name,tics[i].name);
	}
	else
	{
		if(is_fp && !cat_ranges)
		{
		   G_get_fp_range_min_max (&fp_range, &range_dmin, &range_dmax);
		   if(G_is_d_null_value(&range_dmin) || G_is_d_null_value(&range_dmax))
		      G_fatal_error("Floating point data range is empty");
                }
		tic_every = 1;
		tic_unit = 1;
	}

	/* X-AXIS LOOP
 *
 * loop through category range, drawing a pie-slice and a
 * legend bar on each iteration evenly divisible, a tic-mark
 * on those evenly divisible by tic_unit, and a tic_mark
 * number on those evenly divisible by tic_every
 *
 */
	ptr = dist_stats->ptr;
	for (i=dist_stats->mincat; i<=dist_stats->maxcat; i++)
	{
		if (!ptr)
			break;
		draw=NO;
		/* figure bar color and height 
    *
    * the cat number determines the color, the corresponding stat,
    * determines the bar height.  if a stat cannot be found for the
    * cat, then it doesn't drow anything, before it used to draw the
    * box of size 0 in black. Later when the option to provide the
    * background color will be added , we might still draw a box in
    * this color.
    */
		if(nodata && i==dist_stats->mincat)
		{
	 	        if (dist_stats->null_stat == 0 && xscale > 1)
				draw=NO;
			else
			{
				draw=YES;
		                G_set_c_null_value(&bar_color,1);
				bar_height =
				  (int)(yoffset-yscale*(double)dist_stats->null_stat);
			}
                }
		else if (ptr->cat == i) /* AH-HA!! found the stat */
		{
			if (ptr->stat == 0 && xscale > 1)
				draw=NO;
			else
			{
				draw=YES;
				bar_color = ptr->cat;
				bar_height =
				  (int)(yoffset-yscale*(double)ptr->stat);
			}
			if (ptr->next != NULL)
				ptr=ptr->next;
		}
		else /* we have to look for the stat */
		{
			/* loop until we find it, or pass where it should be */
			while (ptr->cat < i && ptr->next != NULL)
				ptr = ptr->next;
			if (ptr->cat == i) /* AH-HA!! found the stat */
			{
				if (ptr->stat == 0 && xscale > 1)
					draw=NO;
				else
				{
					draw=YES;
					bar_color = ptr->cat;
					bar_height =
					   (int)(yoffset-yscale*(double)ptr->stat);
				}
				if (ptr->next != NULL)
					ptr=ptr->next;
			}
			else /* stat cannot be found */
			{
				if (xscale > 1)
				{
					draw=NO;

#ifdef notdef 
					draw=YES;
					bar_color = D_translate_color("black");
					bar_height = yoffset; /* zero */
#endif
				}
				else
					draw=NO;
			}
		}

		/* draw the bar */
		if (draw==YES)
		{
			if (xscale != 1)
			{
				/* draw the bar as a box */
				if(!G_is_c_null_value(&bar_color) && is_fp)
				{
				     if(cat_ranges)
				       G_get_ith_d_raster_cat(&cats, bar_color, 
						 &dmin, &dmax);
                                     else
				     {
				       dmin=range_dmin+(double)i*
  				         (range_dmax-range_dmin)/(double)nsteps;
				       dmax=range_dmin+(double)(i+1)*
  				         (range_dmax-range_dmin)/(double)nsteps;
                                     }
				     if(dmin != dmax)
				     {
					for(j=0; j < xscale; j++)
					{
					   dval = dmin + j * (dmax-dmin)/ xscale;
					   D_d_color(dval, colors);
					   x_box[0]= x_box[1] = xoffset+((i-dist_stats->mincat)*xscale-0.5*xscale + j);
					   x_box[2]= x_box[3] = xoffset+((i-dist_stats->mincat)*xscale-0.5*xscale + j + 1);
					   y_box[0]= y_box[3] = yoffset;
					   y_box[1]= y_box[2] = bar_height;
					   R_polygon_abs(x_box,y_box,4);
                                        }
                                     }
				     else  /* 1-color bar */
				     {
					D_d_color(dmin, colors);
				        x_box[0]= x_box[1] = xoffset+((i-dist_stats->mincat)*xscale-0.5*xscale);
				        x_box[2]= x_box[3] = xoffset+((i-dist_stats->mincat)*xscale+0.5*xscale);
				        y_box[0]= y_box[3] = yoffset;
			     	        y_box[1]= y_box[2] = bar_height;
				        R_polygon_abs(x_box,y_box,4);
                                     }
				}/* fp */
			        else /* 1-color bar for int data or null */
			        {
			             D_color((CELL)bar_color, colors);
			             x_box[0]= x_box[1] = xoffset+((i-dist_stats->mincat)*xscale-0.5*xscale);
			             x_box[2]= x_box[3] = xoffset+((i-dist_stats->mincat)*xscale+0.5*xscale);
			             y_box[0]= y_box[3] = yoffset;
		     	             y_box[1]= y_box[2] = bar_height;
			             R_polygon_abs(x_box,y_box,4);
                                }
			}
			else
			{
				/* draw the bar as a line */
				if(is_fp) 
				{
				     if(cat_ranges)
				       G_get_ith_d_raster_cat(&cats, bar_color, 
						 &dmin, &dmax);
                                     else
				     {
				       dmin=range_dmin+(double)i*
  				         (range_dmax-range_dmin)/(double)nsteps;
				       dmax=range_dmin+(double)(i+1)*
  				         (range_dmax-range_dmin)/(double)nsteps;
                                     }
                                     D_d_color(dmin, colors);
                                }
				else
				     D_color((CELL)bar_color, colors);
				x_box[0] = x_box[1] = xoffset+(i-dist_stats->mincat)*xscale;
				y_box[0] = yoffset;
				y_box[1] = bar_height;
				R_move_abs((int)x_box[0],(int)y_box[0]);
				R_cont_abs((int)x_box[1],(int)y_box[1]);
			}
		}

		/* draw x-axis tic-marks and numbers */
		/* draw tick for null and for numbers at every tic step
		   except when there is null, don't draw tic for mincat+1 */

		if ((rem((long int)i,tic_every)==(float)0 || 
		      i==dist_stats->mincat && nodata) 
		      && !(nodata && i==dist_stats->mincat+1))
		{
			/* draw a numbered tic-mark */
			R_standard_color(color);
			R_move_abs( (int)(xoffset+(i-dist_stats->mincat)*xscale - 0.5 * xscale),
			    (int)(b-ORIGIN_Y*(b-t)) );
			R_cont_rel( (int)0 , (int)(BIG_TIC*(b-t)) );
		        if(nodata && i==dist_stats->mincat)
			   sprintf(txt, "null");
			else if(is_fp)
			   sprintf(txt,"%d",(int) (dmin/(double) tic_unit));
                        else
			   sprintf(txt,"%d",(int) (i/tic_unit));
			text_height = (b-t)*TEXT_HEIGHT;
			text_width = (r-l)*TEXT_WIDTH;
			R_text_size(text_width,text_height);
			R_get_text_box(txt,&tt,&tb,&tl,&tr);
			while ((tr-tl) > XTIC_DIST)
			{
				text_width *= 0.75;
				text_height *= 0.75;
				R_text_size(text_width,text_height);
				R_get_text_box(txt,&tt,&tb,&tl,&tr);
			}
			R_move_abs((int)(xoffset+(i-dist_stats->mincat)*xscale - 0.5 * xscale -(tr-tl)/2),
			    (int)(b-XNUMS_Y*(b-t)));
			R_text(txt);
		}
		else if (rem(i,tic_unit)==(float)0)
		{
			/* draw a tic-mark */
			R_standard_color(color);
			R_move_abs( (int)(xoffset+(i-dist_stats->mincat)*xscale- 0.5 * xscale),
			    (int)(b-ORIGIN_Y*(b-t)) );
			R_cont_rel( (int)0 , (int)(SMALL_TIC*(b-t)) );
		}
	}

	/* draw the x-axis label */
	if (tic_unit != 1)
		sprintf(xlabel,"X-AXIS: Cell Values %s",tic_name);
	else
		sprintf(xlabel,"X-AXIS: Cell Values");
	text_height = (b-t)*TEXT_HEIGHT;
	text_width = (r-l)*TEXT_WIDTH;
	R_text_size(text_width,text_height);
	R_get_text_box(xlabel,&tt,&tb,&tl,&tr);
	R_move_abs( (int) (l+(r-l)/2-(tr-tl)/2) , (int) (b-LABEL_1*(b-t)) );
	R_standard_color((int)color);
	R_text(xlabel);

	/* DRAW Y-AXIS TIC-MARKS AND NUMBERS
 * 
 * first, figure tic_every and tic_units for the x-axis of the bar-chart.
 * tic_every tells how often to place a tic-number.  tic_unit tells
 * the unit to use in expressing tic-numbers.
 */

	max_tics = (long)((y_line[1]-y_line[0])/YTIC_DIST);

	if (dist_stats->maxstat == dist_stats->minstat)
		dist_stats->minstat = 0;   /* LOOKS FUNNY TO ME */
	num_stats = dist_stats->maxstat - dist_stats->minstat;
	i=0;
	while ((num_stats/tics[i].every) > max_tics)
		i++;
	tic_every = tics[i].every;
	tic_unit = tics[i].unit;
	strcpy(tic_name,tics[i].name);

	stat_start = tic_unit*((long)(dist_stats->minstat/tic_unit));
	stat_finis = tic_unit*((long)(dist_stats->maxstat/tic_unit));

	/* Y-AXIS LOOP
 *
 */
	for (i=stat_start; i<=stat_finis; i+=tic_unit)
	{
		if (rem(i,tic_every)==(float)0)
		{
			/* draw a tic-mark */
			R_move_abs((int)x_line[0],(int)(yoffset-yscale*i));
			R_cont_rel((int)(-(r-l)*BIG_TIC),(int)0);

			/* draw a tic-mark number */
			sprintf(txt,"%d",(int)(i/tic_unit));
			text_height = (b-t)*TEXT_HEIGHT;
			text_width =(r-l)*TEXT_WIDTH;
			R_text_size(text_width,text_height);
			R_get_text_box(txt,&tt,&tb,&tl,&tr);
			while ((tt-tb) > YTIC_DIST)
			{
				text_width *= 0.75;
				text_height *= 0.75;
				R_text_size(text_width,text_height);
				R_get_text_box(txt,&tt,&tb,&tl,&tr);
			}
			R_move_abs((int)(l+(r-l)*YNUMS_X-(tr-tl)/2),
			    (int)(yoffset-(yscale*i+0.5*(tt-tb))));
			R_text(txt);
		}
		else if (rem(i,tic_unit)==(float)0)
		{
			/* draw a tic-mark */
			R_move_abs((int)x_line[0],(int)(yoffset-yscale*i));
			R_cont_rel((int)(-(r-l)*SMALL_TIC),(int)0);
		}
	}

	/* draw the y-axis label */
	if (tic_unit != 1)
	{
		if (type==COUNT)
			sprintf(xlabel,"Y-AXIS: Number of cells %s",tic_name);
		else 
			sprintf(xlabel,"Y-AXIS: Area %s sq. meters",tic_name);
	}
	else
	{
		if (type==COUNT)
			sprintf(xlabel,"Y-AXIS: Number of cells");
		else
			sprintf(xlabel,"Y-AXIS: Area");
	}

	text_height = (b-t)*TEXT_HEIGHT;
	text_width = (r-l)*TEXT_WIDTH;
	R_text_size(text_width,text_height);
	R_get_text_box(xlabel,&tt,&tb,&tl,&tr);
	R_move_abs((int)(l+(r-l)/2-(tr-tl)/2),(int)(b-LABEL_2*(b-t)));
	R_standard_color((int)color);
	R_text(xlabel);

	/* draw x and y axis lines */
	R_standard_color(color);
	R_polyline_abs(x_line,y_line,3);

	return 0;
}


float 
rem (long int x, long int y)
{
	long int d = x/y;
	return((float)(x-y*d));
}