#include <stdlib.h>
#include <string.h>

#include <platon/html/escape.h>

#define HTML_ESCAPE_TABLE_TERMINATOR { '\0', NULL }

static struct html_escape_table html_escape_space[] = { /* {{{ */
	{ ' ', "&nbsp;" },
	HTML_ESCAPE_TABLE_TERMINATOR
}; /* }}} */

static struct html_escape_table html_escape_special_chars[] = { /* {{{ */
	{ '\x3C', "&lt;"  },
	{ '\x3E', "&gt;"  },
	{ '\x26', "&amp;" },
	HTML_ESCAPE_TABLE_TERMINATOR
}; /* }}} */

static struct html_escape_table html_escape_quotes[] = { /* {{{ */
	{ '\"', "&quot;" },
	{ '\'', "&#039;" },
	HTML_ESCAPE_TABLE_TERMINATOR
}; /* }}} */

static struct html_escape_table html_escape_iso8859_1[] = { /* {{{ */
	HTML_ESCAPE_TABLE_TERMINATOR
}; /* }}} */

static struct html_escape_table html_escape_iso8859_2[] = { /* {{{ */
	HTML_ESCAPE_TABLE_TERMINATOR
}; /* }}} */

static struct html_escape_table html_escape_iso8859_15[] = { /* {{{ */
	{ '\xE4', "&auml;"  },
	{ '\xC4', "&Auml;"  },
	{ '\xF6', "&ouml;"  },
	{ '\xD6', "&Ouml;"  },
	{ '\xFC', "&uuml;"  },
	{ '\xDC', "&Uuml;"  },
	{ '\xDF', "&szlig;" },
	{ '\xA4', "&euro;"  },
	HTML_ESCAPE_TABLE_TERMINATOR
}; /* }}} */

static struct html_escape_table *html_escape_tables[] = { /* {{{ */
	html_escape_space,
	html_escape_special_chars,
	html_escape_quotes,
	html_escape_iso8859_1,
	html_escape_iso8859_2,
	html_escape_iso8859_15,
	NULL
}; /* }}} */

	char *
PLATON_FUNC(html_escape)(str, types)
	const char *str;
	const int types;
{ /* {{{ */
	register int i, ii, j, len = 1;
	struct html_escape_table *current_table;
	char *html;

	if ((html = (char *) malloc(1 * sizeof(char))) == NULL)
		return NULL;

	/* Loop through every character of str */
	for (*html = '\0'; *str != '\0'; str++) {

		/* Loop through every HTML escape table */
		for (i = 0, ii = 1; ; i++, ii *= 2) { /* ii == 2^i */
			if ((current_table = html_escape_tables[i]) == NULL)
				break;

			/* Check if table is selected */
			if (! types & ii)
				continue;

			/* Loop though every entity of HTML escape table */
			for (j = 0; current_table[j].html != NULL; j++) {

				/* If character to escape was found */
				if (*str != current_table[j].code)
					continue;

				/* Substitute character with appropriate entity */
				len += strlen(current_table[j].html);
				if ((html = (char *) realloc(html, len)) == NULL)
					return NULL;
				strcat(html, current_table[j].html);
				break;
			}
			if (current_table[j].html != NULL)
				break;
		}

		/* If character was substitued */
		if (current_table != NULL)
			continue;

		/* Just copy character */
		len++;
		if ((html = (char *) realloc(html, len)) == NULL)
			return NULL;
		html[len - 2] = *str;
		html[len - 1] = '\0';
	}

	return html;
} /* }}} */

	char *
PLATON_FUNC(html_unescape)(html, types)
	const char *html;
	const int types;
{ /* {{{ */
	register int i, ii, j, len;
	struct html_escape_table *current_table;
	char *str, *ptr;

	/* String duplication */
	if ((str = strdup(html)) == NULL)
		return NULL;

	/* Loop through every HTML escape table */
	for (i = 0, ii = 1; ; i++, ii *= 2) { /* ii == 2^i */
		if ((current_table = html_escape_tables[i]) == NULL)
			break;

		/* Check if table is selected */
		if (! types & ii)
			continue;

		/* Loop though every entity of HTML escape table */
		for (j = 0; current_table[j].html != NULL; j++) {

			while ((ptr = strstr(str, current_table[j].html)) != NULL) {
				len  = strlen(current_table[j].html);
				if (len <= 0)
					break;
				*ptr = current_table[j].code;
				memmove((void *) (ptr + 1), (void *) (ptr + len),
						strlen(ptr + len) + 1);
			}

		}
	}

	return str;
} /* }}} */

#if defined(SELF) || defined(SELFTEST) || defined(SELF_HTML_ESCAPE) /* {{{ */

#include <stdio.h>

#define TEST_STRING		"<<--'//'-->>"

	int
main(argc, argv)
	int argc;
	char **argv;
{
	register char *s1, *s2;

	s1 = htmlspecialchars(TEST_STRING);
	printf("htmlspecialchars(\"%s\") = \"%s\"\n", TEST_STRING, s1);
	s2 = html_unescape(s1, HTML_ESCAPE_HTMLSPECIALCHARS);
	printf("html_unescape(\"%s\", HTML_ESCAPE_HTMLSPECIALCHARS) = \"%s\"\n", s1, s2);
	free(s2);
	free(s1);

	s1 = htmlentities(TEST_STRING);
	printf("htmlentities(\"%s\") = \"%s\"\n", TEST_STRING, s1);
	s2 = html_unescape(s1, HTML_ESCAPE_HTMLENTITIES);
	printf("html_unescape(\"%s\", HTML_ESCAPE_HTMLENTITIES) = \"%s\"\n", s1, s2);
	free(s2);
	free(s1);

	return 0;
}

#endif /* #if defined(SELF) || defined(SELFTEST) || defined(SELF_STRCGI) */ /* }}} */

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