/*
 * Copyright © 2001 Keith Packard and Carl Worth
 * All Rights Reserved.  See the file COPYING in this directory
 * for licensing information.
 */

int style_b = 1;
int style_em = 2;
int style_i = 4;
int style_s = 8;
int style_tt = 16;

int[*] colornames = {'r', 'g', 'b', 'c', 'm', 'y', 'k', 'w'};

typedef struct {
    int styles;
    int underline; /* "root underline" is 0 */
    int color; /* "root color" is -1 */
    int size; /* "root size" is -1 */
} context;

*context no_context = reference ((context) {});

context root_context = (context) {
    .styles=0, .underline=0, .color=-1, .size=-1
};

public exception UnknownColor (int name);

int function color_index_for_name(int n) {
    int i;
    for (i=0; i<dim(colornames); i++)
	if (colornames[i] == n)
	    return i;
    raise UnknownColor (n);
}

function context_set (*context c, string value)
{
    switch (value) {
    case "B":
	c->styles |= style_b;
	break;
    case "EM":
	if ((c->styles & style_s) == 0) {
	    c->styles ^= style_em;
	}
	break;
    case "I":
	c->styles |= style_i;
	break;
    case "PL":
	c->styles &= ~(style_s | style_em | style_i | style_b | style_tt);
	c->underline = 0;
	break;
    case "S":
	c->styles |= style_s;
	c->styles &= ~style_em;
	break;
    case "TT":
	c->styles |= style_tt;
	break;
    case "U":
	if (c->underline < 3) {
	    c->underline++;
	}
	break;
    default:
	if (value[0] >= '0' && value[0] <= '9') {
	    c->size = string_to_integer(value);
	} else {
	    c->color = color_index_for_name(value[0]);
	}
    }
}

function context_dump (context c)
{
    printf("%s %s %s %s %s %d %s %s ",
	   (c.styles & style_b) != 0 ? "B" : "-",
	   (c.styles & style_em) != 0 ? "EM" : "--",
	   (c.styles & style_i) != 0 ? "I" : "-",
	   (c.styles & style_s) != 0 ? "S" : "-",
	   (c.styles & style_tt) != 0 ? "TT" : "--",
	   c.underline,
	   (c.color >= 0) ? String::new (colornames[c.color]) : "-",
	   (c.size >= 0) ? String::new (c.size) : "-");
}