cprintf.c

// SPDX-License-Identifier: MIT
/*
 *
 * This file is part of cprintf, with ABSOLUTELY NO WARRANTY.
 *
 * MIT License
 *
 * Copyright (c) 2024 Moe-hacker
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 *
 */
#include "include/cprintf.h"

//
// Generic support.
//

// For marking the buffer, so that it can be free() later.
static thread_local char **cprintf_buffer = NULL;
static thread_local size_t cprintf_buf_count = 0;
void cprintf_mark_buf__(char *b)
{
	/*
	 * Mark the buffer, so that it can be free() later.
	 */
	cprintf_buffer = realloc(cprintf_buffer, (cprintf_buf_count + 1) * sizeof(char *));
	cprintf_buffer[cprintf_buf_count] = b;
	cprintf_buf_count++;
}
void cprintf_free_buf__(void)
{
	/*
	 * Free all the buffers that have been marked.
	 */
	for (size_t i = 0; i < cprintf_buf_count; i++) {
		free(cprintf_buffer[i]);
	}
	free(cprintf_buffer);
	cprintf_buffer = NULL;
	cprintf_buf_count = 0;
}
char *cprintf_regen_format__(const char *f)
{
	/*
	 * This function will regenerate the format string
	 * to replace all '{}' with '%s'.
	 * If the input is NULL, it will return an empty string.
	 */
	char *ret = strdup(cprintf_avoid_null__(f));
	int j = 0;
	size_t len = cprintf_strlen__(f);
	if (len == 0) {
		cprintf_mark_buf__(ret);
		return ret;
	}
	for (size_t i = 0; i < len - 1; i++) {
		if (f[i] == '{' && f[i + 1] == '}') {
			ret[j] = '%';
			ret[j + 1] = 's';
			j += 2;
			i++;
		} else {
			ret[j] = f[i];
			j++;
		}
	}
	ret[j] = '\0';
	if (f[len - 1] != '}') {
		ret[j] = f[len - 1];
		ret[j + 1] = '\0';
	}
	cprintf_mark_buf__(ret);
	return ret;
}
//
// Color support.
//
struct CPRINTF_COLOR__ cprintf_color = {
	.base = "254;228;208",
	.black_fg = "\033[30m",
	.red_fg = "\033[31m",
	.green_fg = "\033[32m",
	.yellow_fg = "\033[33m",
	.blue_fg = "\033[34m",
	.purple_fg = "\033[35m",
	.cyan_fg = "\033[36m",
	.white_fg = "\033[37m",
	.black_bg = "\033[40m",
	.red_bg = "\033[41m",
	.green_bg = "\033[42m",
	.yellow_bg = "\033[43m",
	.blue_bg = "\033[44m",
	.purple_bg = "\033[45m",
	.cyan_bg = "\033[46m",
	.white_bg = "\033[47m",
};
bool cprintf_print_color_only_tty = true;
#define fprintf_only_tty(stream, ...)                                                               \
	{                                                                                           \
		if (!cprintf_print_color_only_tty) {                                                \
			fprintf(stream, __VA_ARGS__);                                               \
		} else {                                                                            \
			struct stat _stat_buf;                                                      \
			if (fstat(fileno(stream), &_stat_buf) == 0 && S_ISCHR(_stat_buf.st_mode)) { \
				fprintf(stream, __VA_ARGS__);                                       \
			}                                                                           \
		}                                                                                   \
	}
static void fprint_rgb_fg_color(FILE *_Nonnull stream, const char *_Nonnull color)
{
	/*
	 * print \033[1;38;2;R;G;Bm format color.
	 */
	char buf[17];
	for (size_t i = 1; i < strlen(color) - 1; i++) {
		buf[i - 1] = color[i];
		buf[i] = 0;
	}
	fprintf_only_tty(stream, "\033[38;2;%sm", buf);
}
static void fprint_rgb_bg_color(FILE *_Nonnull stream, const char *_Nonnull color)
{
	/*
	 * print \033[1;38;2;R;G;Bm format color.
	 */
	char buf[17];
	for (size_t i = 1; i < strlen(color) - 1; i++) {
		buf[i - 1] = color[i];
		buf[i] = 0;
	}
	fprintf_only_tty(stream, "\033[48;2;%sm", buf);
}
static bool is_rgb_color(const char *_Nonnull color)
{
	/*
	 * Check if color is an R;G;B format color.
	 */
	int sem = 0;
	// If R > 255, it's not a color.
	if (atoi(color) > 255) {
		return false;
	}
	for (size_t i = 1; i < strlen(color) - 1; i++) {
		if (color[i] == ';') {
			sem++;
			// If G or B > 255, it's not a color.
			if (atoi(&color[i + 1]) > 255) {
				return false;
			}
		}
		// If there are more than 2 `;`, the format is not correct.
		if (sem > 2) {
			return false;
		}
		// If the color include other charactor, the format is not correct.
		if (!isdigit(color[i]) && color[i] != ';') {
			return false;
		}
	}
	// If there are not 2 `;`, the format is not correct.
	if (sem != 2) {
		return false;
	}
	return true;
}
static const char *cfprintf_print_fg_color(FILE *_Nonnull stream, const char *_Nonnull buf)
{
	/*
	 * Only valid {color} will be recognized,
	 * and for other '{' without 'color}', we print a '{'.
	 * we return the pointer to the last character that is
	 * not recognized as color.
	 */
	const char *ret = buf;
	char color[17] = { '\0' };
	for (int i = 0; i < 16; i++) {
		if (buf[i] == '\0') {
			fprintf(stream, "{");
			return buf;
		}
		if (buf[i] == '}') {
			color[i] = buf[i];
			color[i + 1] = 0;
			ret = &(buf[i]);
			break;
		}
		color[i] = buf[i];
		color[i + 1] = 0;
	}
	if (strcmp(color, "{clear}") == 0) {
		fprintf_only_tty(stream, "\033[0m");
	} else if (strcmp(color, "{black}") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.black_fg);
	} else if (strcmp(color, "{red}") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.red_fg);
	} else if (strcmp(color, "{green}") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.green_fg);
	} else if (strcmp(color, "{yellow}") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.yellow_fg);
	} else if (strcmp(color, "{blue}") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.blue_fg);
	} else if (strcmp(color, "{purple}") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.purple_fg);
	} else if (strcmp(color, "{cyan}") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.cyan_fg);
	} else if (strcmp(color, "{white}") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.white_fg);
	} else if (strcmp(color, "{base}") == 0) {
		fprintf_only_tty(stream, "\033[1;38;2;%sm", cprintf_color.base);
	} else if (strcmp(color, "{underline}") == 0) {
		fprintf_only_tty(stream, "\033[4m");
	} else if (strcmp(color, "{highlight}") == 0) {
		fprintf_only_tty(stream, "\033[1m");
	} else if (is_rgb_color(color)) {
		fprint_rgb_fg_color(stream, color);
	} else {
		ret = buf;
		fprintf(stream, "{");
	}
	return ret;
}
static const char *cfprintf_print_bg_color(FILE *_Nonnull stream, const char *_Nonnull buf)
{
	/*
	 * Only valid [color] will be recognized,
	 * and for other '[' without 'color[', we print a '['.
	 * we return the pointer to the last character that is
	 * not recognized as color.
	 */
	const char *ret = buf;
	char color[17] = { '\0' };
	for (int i = 0; i < 16; i++) {
		if (buf[i] == '\0') {
			fprintf(stream, "[");
			return buf;
		}
		if (buf[i] == ']') {
			color[i] = buf[i];
			color[i + 1] = 0;
			ret = &(buf[i]);
			break;
		}
		color[i] = buf[i];
		color[i + 1] = 0;
	}
	if (strcmp(color, "[clear]") == 0) {
		fprintf_only_tty(stream, "\033[0m");
	} else if (strcmp(color, "[black]") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.black_bg);
	} else if (strcmp(color, "[red]") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.red_bg);
	} else if (strcmp(color, "[green]") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.green_bg);
	} else if (strcmp(color, "[yellow]") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.yellow_bg);
	} else if (strcmp(color, "[blue]") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.blue_bg);
	} else if (strcmp(color, "[purple]") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.purple_bg);
	} else if (strcmp(color, "[cyan]") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.cyan_bg);
	} else if (strcmp(color, "[white]") == 0) {
		fprintf_only_tty(stream, "%s", cprintf_color.white_bg);
	} else if (strcmp(color, "[base]") == 0) {
		fprintf_only_tty(stream, "\033[1;48;2;%sm", cprintf_color.base);
	} else if (strcmp(color, "[underline]") == 0) {
		fprintf_only_tty(stream, "\033[4m");
	} else if (strcmp(color, "[highlight]") == 0) {
		fprintf_only_tty(stream, "\033[1m");
	} else if (is_rgb_color(color)) {
		fprint_rgb_bg_color(stream, color);
	} else {
		ret = buf;
		fprintf(stream, "[");
	}
	return ret;
}
int cprintf__(const char *_Nonnull buf)
{
	const char *p = NULL;
	p = buf;
	for (size_t i = 0; i < strlen(buf); i++) {
		// Search for '{'.
		if (*p == '{') {
			// *p will be moved because we need to skip the {color} string.
			p = cfprintf_print_fg_color(stdout, p);
		} else if (*p == '[') {
			// *p will be moved because we need to skip the [color] string.
			p = cfprintf_print_bg_color(stdout, p);
		} else {
			printf("%c", *p);
		}
		// Recompute the value of i.
		i = (size_t)(p - buf);
		// Goto the next charactor.
		p = &(p[1]);
	}
	// We will always reset the color in the end.
	fprintf_only_tty(stdout, "\033[0m");
	fflush(stdout);
	return 114514;
}
int cfprintf__(FILE *_Nonnull stream, const char *_Nonnull buf)
{
	const char *p = NULL;
	p = buf;
	for (size_t i = 0; i < strlen(buf); i++) {
		// Search for '{' or '['.
		if (*p == '{') {
			// *p will be moved because we need to skip the {color} string.
			p = cfprintf_print_fg_color(stream, p);
		} else if (*p == '[') {
			// *p will be moved because we need to skip the {color} string.
			p = cfprintf_print_bg_color(stream, p);
		} else {
			fprintf(stream, "%c", *p);
		}
		// Recompute the value of i.
		i = (size_t)(p - buf);
		// Goto the next charactor.
		p = &(p[1]);
	}
	// We will always reset the color in the end.
	fprintf_only_tty(stream, "\033[0m");
	fflush(stream);
	return 114514;
}
jmp_buf cprintf_jmp_buf;
void cp_time_out(int sig)
{
	/*
	 * This function is used to handle the timeout signal.
	 * It will do nothing, just to avoid the program to exit.
	 */
	(void)sig; // Avoid unused parameter warning.
	longjmp(cprintf_jmp_buf, 1);
}
static char *get_bg_color__(void)
{
	/*
	 * Only xterm **might** support this.
	 * At least, better than nothing.
	 * It works with magic on my machine :)
	 */
	int stat = setjmp(cprintf_jmp_buf);
	if (stat) {
		// If we got a timeout, we will return NULL.
		return NULL;
	}
	struct termios old_termios, new_termios;
	tcgetattr(STDERR_FILENO, &old_termios);
	new_termios = old_termios;
	// Don't ask me why, idk QwQ
	cfmakeraw(&new_termios);
	tcsetattr(STDERR_FILENO, TCSANOW, &new_termios);
	write(STDERR_FILENO, "\x1b]11;?\a", strlen("\x1b]11;?\a"));
	char buf[128];
	buf[0] = '\0';
	// Don't ask me why, idk QwQ
	struct sigaction sa;
	sa.sa_handler = cp_time_out;
	sigaction(SIGALRM, &sa, NULL);
	// Set a timeout of 0.1 second.
	struct itimerval timer;
	timer.it_value.tv_sec = 0;
	// Timeout of 0.2 second.
	// And we will wait for the response for 0.1 second.
	// So the real timeout is 0.1 second.
	timer.it_value.tv_usec = 200000;
	timer.it_interval.tv_sec = 0;
	timer.it_interval.tv_usec = 0;
	setitimer(ITIMER_REAL, &timer, NULL);
	// Sleep for 0.1 second to wait for the response.
	usleep(100000);
	int n = read(STDERR_FILENO, buf, sizeof(buf) - 1);
	if (n < 0) {
		// If read failed, we will return NULL.
		return NULL;
	}
	// Reset the timer.
	sigaction(SIGALRM, NULL, NULL);
	// At least I know this nya~
	// restore the old termios settings.
	tcsetattr(STDERR_FILENO, TCSANOW, &old_termios);
	fflush(stderr);
	if (n > 0) {
		buf[n] = '\0';
		int j = 0;
		char *p = strstr(buf, "rgb:");
		if (!p) {
			return NULL;
		}
		p += strlen("rgb:");
		char *ret = malloc(32);
		for (size_t i = 0; i < strlen(p); i++) {
			if (p[i] >= 32 && p[i] <= 126) {
				ret[j++] = p[i];
				ret[j] = '\0';
			}
		}
		return ret;
	} else {
		return NULL;
	}
}
bool cp_xterm_is_dark_mode(void)
{
	struct stat _stat_buf;
	if (fstat(STDERR_FILENO, &_stat_buf) != 0 || !S_ISCHR(_stat_buf.st_mode)) {
		// If stderr is not a terminal,
		// we cannot determine the background color.
		return false;
	}
	char *bg_color = get_bg_color__();
	if (!bg_color)
		return false;
	char *r_str = strtok(bg_color, "/");
	char *g_str = strtok(NULL, "/");
	char *b_str = strtok(NULL, "/");
	if (!r_str || !g_str || !b_str) {
		free(bg_color);
		return false;
	}
	unsigned int r = (unsigned int)strtol(r_str, NULL, 16);
	unsigned int g = (unsigned int)strtol(g_str, NULL, 16);
	unsigned int b = (unsigned int)strtol(b_str, NULL, 16);
	// ITU-R BT.601 luminance.
	// It works, why?
	// Y = 0.299*R + 0.587*G + 0.114*B
	double luminance = r * 0.299 + g * 0.587 + b * 0.114;
	free(bg_color);
	return (luminance <= 32768.0);
}