bluelib/term/paragraph.c

#include "print.h"

#include <blue/object/string.h>
#include <blue/term.h>
#include <ctype.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

#define DEFAULT_PARAGRAPH_WIDTH 160

static void indent(
	struct b_paragraph_format *format, FILE *fp, unsigned int margin, bool tty)
{
	unsigned int x = 0;
	while (x < margin) {
		fputs(" ", fp);
		x++;
	}
}

static unsigned int extract_line(
	const char **sp, unsigned int line_length, b_string *out,
	struct b_paragraph_format *format)
{
	const char *start = *sp;
	while (isspace(*start) || *start == '\n') {
		start++;
	}

	if (!*start) {
		return 0;
	}

	const char *end = NULL;

	unsigned int delta = 0;
	unsigned int i;
	for (i = 0; start[i]; i++) {
		if (start[i] == '\033') {
			while (!isalpha(start[i++])) {
				delta++;
			}

			delta++;
		}

		if (!isspace(start[i]) && start[i] != '\n') {
			continue;
		}

		if ((i - delta) >= line_length) {
			break;
		}

		end = &start[i];

		if (start[i] == '\n') {
			break;
		}
	}

	if (start[i] == '\0' && (i - delta) < line_length) {
		end = NULL;
	}

	unsigned int len;
	if (end) {
		len = end - start;
	} else {
		len = strlen(start);
	}

	b_string_insert_cstrn(out, start, len, B_NPOS);

	*sp = end;

	return len;
}

static b_status print_paragraph_tty(
	const char *str, FILE *fp, struct b_paragraph_format *format)
{
	unsigned int w = 0, h = 0;
	z__b_stream_dimensions(fp, &w, &h);

	if (!w) {
		w = DEFAULT_PARAGRAPH_WIDTH;
	}

	unsigned int left_margin = format->p_left_margin;
	unsigned int line_length = format->p_line_length;

	if (format->p_left_margin + format->p_right_margin >= w) {
		return B_SUCCESS;
	}

	unsigned int page_width
		= w - format->p_left_margin - format->p_right_margin;
	if (page_width < line_length || line_length == 0) {
		line_length = page_width;
	}

	if (!(format->p_flags & B_PARAGRAPH_DONT_INDENT_FIRST_LINE)) {
		indent(format, fp, left_margin, true);
	}

	b_string *line = b_string_create();
	bool need_indent = false;

	while (str) {
		if (*str == '\n') {
			if (format->p_flags & B_PARAGRAPH_DOUBLE_LINE_BREAK) {
				fputc('\n', fp);
			}

			str++;
			need_indent = true;

			while (*str == '\n') {
				if (format->p_flags & B_PARAGRAPH_MULTI_LINE_BREAK) {
					fputc('\n', fp);
				}

				str++;
			}
		}

		b_string_clear(line);
		unsigned int this_line
			= extract_line(&str, line_length, line, format);
		if (this_line == 0) {
			break;
		}

		if (need_indent) {
			indent(format, fp, left_margin, false);
		}

		b_fprintf(fp, "%s\n", b_string_ptr(line));
		need_indent = true;
	}

	b_string_release(line);

	return B_SUCCESS;
}

static b_status print_paragraph_file(
	const char *str, FILE *fp, struct b_paragraph_format *format)
{
	return B_SUCCESS;
}

b_status b_print_paragraph(
	const char *str, FILE *fp, struct b_paragraph_format *format)
{
	if (z__b_stream_is_tty(fp)) {
		return print_paragraph_tty(str, fp, format);
	}

	return print_paragraph_tty(str, fp, format);
}