#include <kern/ansi.h>

uint8_t vga_colors[8] = {
	[0] = 0,
	[1] = 4,
	[2] = 2,
	[3] = 6,
	[4] = 1,
	[5] = 5,
	[6] = 3,
	[7] = 7
};

void
ansi_step(void (*putcf)(int), int c, struct AttrState* s) {
	switch(s->state) {
		case NORMAL:
			if(c != 27) putcf(c | (s->cattrs << 8));
			else s->state = ESC;
			return;
		case ESC:
			s->state = (c == '[') ? BRACKET : NORMAL;
			return;
		case BRACKET:
			if(c == '3') {
				s->state = COLOR_FG;
			} else if(c == '0') {
				s->state = COLOR;
				s->attrs = 0;
			} else {
				s->state = NORMAL;
			}
			return;
		case COLOR_FG:
			if(c >= '0' && c <= '9') {
				s->attrs = (s->attrs & ~(0x07)) | vga_colors[c - '0'];
				c |= ((c - '0') << 8);
				s->state = COLOR;
			} else {
				s->state = NORMAL;
			}
			return;
		case COLOR:
			s->state = (c == ';') ? BRACKET : NORMAL;
			if(c == 'm') s->cattrs = s->attrs;
			return;
	}
}