/*
 * Text layout and parsing functions
 *
 * Copyright (C) 2019  Patrick McDermott
 *
 * This file is part of fbcon2png.
 *
 * fbcon2png is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * fbcon2png is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with fbcon2png.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "text.h"

#include <stdlib.h>

#include <png.h>

#include "font.h"

#define MAX(a, b) (((a) > (b)) ? (a) : (b))

struct text {
	const char *string;
	int         width;
	int         height;
};

struct text *
text_new(const char *string)
{
	struct text *text;
	int          width;
	int          eol;

	if (!string) {
		return NULL;
	}
	text = calloc(1, sizeof(*text));
	if (!text) {
		return NULL;
	}

	text->string = string;

	width = 0;
	eol = 0;
	while (string && *string) {
		if (*string == 0x1B && *(string + 1) == '[') {  /* CSI */
			string += 2;
			for (; *string >= 0x30 && *string <= 0x3F; ++string);
			for (; *string >= 0x20 && *string <= 0x2F; ++string);
			if (*string >= 0x40 && *string <= 0x7E) {
				++string;
			}
			eol = 0;
		} else if (*string == '\n') {
			text->width = MAX(text->width, width);
			width = 0;
			++text->height;
			++string;
			eol = 1;
		} else {
			++width;
			++string;
			eol = 0;
		}
	}
	if (!eol) {
		++text->height;
	}

	return text;
}

int
text_get_width(struct text *text)
{
	return text->width;
}

int
text_get_height(struct text *text)
{
	return text->height;
}

void
text_render(struct text *text, struct font *font, png_bytepp rows)
{
	const char *string;
	size_t      row;
	size_t      col;
	png_color   fg = {255, 255, 255};
	png_color   bg = {  0,   0,   0};

	string = text->string;

	row = 0;
	col = 0;
	while (string && *string) {
		if (*string == 0x1B && *(string + 1) == '[') {  /* CSI */
			string += 2;
			for (; *string >= 0x30 && *string <= 0x3F; ++string);
			for (; *string >= 0x20 && *string <= 0x2F; ++string);
			if (*string >= 0x40 && *string <= 0x7E) {
				++string;
			}
		} else if (*string == '\n') {
			for (; col < text->width; ++col) {
				font_render(font, &fg,&bg, ' ', rows, row, col);
			}
			col = 0;
			++row;
			++string;
		} else {
			font_render(font, &fg, &bg, *string, rows, row, col);
			++col;
			++string;
		}
	}
	for (; col < text->width; ++col) {
		font_render(font, &fg, &bg, ' ', rows, row, col);
	}
}

struct text *
text_destroy(struct text **text_p)
{
	struct text *text;

	text = *text_p;

	free(text);
	return text = NULL;
}