#include "terminal.h"

#define RESET_STR_SIZE 7
#define COLOR4_MAX_SIZE 10


usize max_out(usize wid, usize hgt)
{
	return RESET_STR_SIZE
		+ wid * hgt * COLOR4_MAX_SIZE
		+ wid * hgt * UTF8_MAX_SIZE
		+ hgt
		+ 1;
}

void CreateTerminal(Alloc *pool, struct Terminal *term, usize wid, usize hgt)
{
	term->col4s = pool->alloc(wid * hgt, sizeof(struct Color4));
	term->utf8s = pool->alloc(wid * hgt, UTF8_MAX_SIZE);
	term->out = pool->alloc(wid * hgt, max_out(wid, hgt));

	if (pool->oom)
		return;

	term->wid = wid;
	term->hgt = hgt;
}

usize u8_to_str(char *out, u8 x)
{
	u8 ones = x % 10;
	u8 tens = x / 10;
	u8 hnds = tens / 10;
	tens %= 10;

	usize len = 0;

	out[len] = hnds + 48;
	len += (hnds != 0);

	out[len] = tens + 48;
	len += (hnds | tens) != 0;

	out[len++] = ones + 48;

	return len;
}

u8 ansi_bg(u8 bg)
{
	return bg + (bg < 8 ? 40 : 92);
}

u8 ansi_fg(u8 fg)
{
	return fg + (fg < 8 ? 30 : 82);
}

usize col4_dif_to_str(char *out, struct Color4 *dif, struct Color4 *col)
{
	if (*(u8 *)dif == *(u8 *)col)
		return 0;

	usize len = 0;

	out[len++] = '\x1b';
	out[len++] = '[';

	if (dif->bg != col->bg) {
		len += u8_to_str(out + len, ansi_bg(col->bg));

		if (dif->fg != col->fg) {
			out[len++] += ';';
			len += u8_to_str(out + len, ansi_fg(col->fg));
		}
	} else if (dif->fg != col->fg) {
		len += u8_to_str(out + len, ansi_fg(col->fg));
	}

	out[len++] = 'm';
	*dif = *col;

	return len;
}

usize utf8_to_str(char *out, char utf8[4])
{
	if (utf8[0] == 0)
		utf8[0] = '#';

	out = utf8;
	return 1 + (utf8[1] != 0) + (utf8[2] != 0) + (utf8[3] != 0);
}

usize TerminalPrint(struct Terminal *term)
{
	term->out = (char[3]) { '\x1b', '[', 'H' };
	usize len = 3;

	struct Color4 dif = {0};

	char (*utf8)[4] = term->utf8s;
	struct Color4 *col4 = term->col4s;

	for (usize y = 0; y < term->hgt; y++) {
	for (usize x = 0; x < term->wid; x++, utf8++, col4++) {
		len += col4_dif_to_str(term->out + len, &dif, col4);
		len += utf8_to_str(term->out + len, *utf8);
	}
		term->out[len++] = '\n';
	}

	*(term->out + len) = (char[4]) { '\x1b', '[', '0', 'm' };
	len += 4;

	term->out[len] = '\0';
	return len;
}