asterisk/main/xmldoc.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2008, Eliel C. Sardanons (LU1ALY) <eliels@gmail.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief XML Documentation API
 *
 * \author Eliel C. Sardanons (LU1ALY) <eliels@gmail.com>
 *
 * \extref libxml2 http://www.xmlsoft.org/
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/_private.h"
#include "asterisk/paths.h"
#include "asterisk/linkedlists.h"
#include "asterisk/strings.h"
#include "asterisk/config.h"
#include "asterisk/term.h"
#include "asterisk/xmldoc.h"

#ifdef AST_XML_DOCS

/*! \brief Default documentation language. */
static const char default_documentation_language[] = "en_US";

/*! \brief Number of columns to print when showing the XML documentation with a
 *         'core show application/function *' CLI command. Used in text wrapping.*/
static const int xmldoc_text_columns = 74;

/*! \brief This is a value that we will use to let the wrapping mechanism move the cursor
 *         backward and forward xmldoc_max_diff positions before cutting the middle of a
 *         word, trying to find a space or a \n. */
static const int xmldoc_max_diff = 5;

/*! \brief XML documentation language. */
static char documentation_language[6];

/*! \brief XML documentation tree */
struct documentation_tree {
	char *filename;					/*!< XML document filename. */
	struct ast_xml_doc *doc;			/*!< Open document pointer. */
	AST_RWLIST_ENTRY(documentation_tree) entry;
};

static char *xmldoc_get_syntax_cmd(struct ast_xml_node *fixnode, const char *name, int printname);
static int xmldoc_parse_enumlist(struct ast_xml_node *fixnode, const char *tabs, struct ast_str **buffer);

/*!
 * \brief Container of documentation trees
 *
 * \note A RWLIST is a sufficient container type to use here for now.
 *       However, some changes will need to be made to implement ref counting
 *       if reload support is added in the future.
 */
static AST_RWLIST_HEAD_STATIC(xmldoc_tree, documentation_tree);

static const struct strcolorized_tags {
	const char *init;      /*!< Replace initial tag with this string. */
	const char *end;       /*!< Replace end tag with this string. */
	const int colorfg;     /*!< Foreground color. */
	const char *inittag;   /*!< Initial tag description. */
	const char *endtag;    /*!< Ending tag description. */
} colorized_tags[] = {
	{ "<",  ">",  COLOR_GREEN,  "<replaceable>", "</replaceable>" },
	{ "\'", "\'", COLOR_BLUE,   "<literal>",     "</literal>" },
	{ "*",  "*",  COLOR_RED,    "<emphasis>",    "</emphasis>" },
	{ "\"", "\"", COLOR_YELLOW, "<filename>",    "</filename>" },
	{ "\"", "\"", COLOR_CYAN,   "<directory>",   "</directory>" },
	{ "${", "}",  COLOR_GREEN,  "<variable>",    "</variable>" },
	{ "",   "",   COLOR_BLUE,   "<value>",       "</value>" },
	{ "",   "",   COLOR_BLUE,   "<enum>",        "</enum>" },
	{ "\'", "\'", COLOR_GRAY,   "<astcli>",      "</astcli>" },

	/* Special tags */
	{ "", "", COLOR_YELLOW, "<note>",   "</note>" },
	{ "", "", COLOR_RED,   "<warning>", "</warning>" }
};

static const struct strspecial_tags {
	const char *tagname;		/*!< Special tag name. */
	const char *init;		/*!< Print this at the beginning. */
	const char *end;		/*!< Print this at the end. */
} special_tags[] = {
	{ "note",    "<note>NOTE:</note> ",             "" },
	{ "warning", "<warning>WARNING!!!:</warning> ", "" }
};

/*! \internal
 *  \brief Calculate the space in bytes used by a format string
 *         that will be passed to a sprintf function.
 *  \param postbr The format string to use to calculate the length.
 *  \retval The postbr length.
 */
static int xmldoc_postbrlen(const char *postbr)
{
	int postbrreallen = 0, i;
	size_t postbrlen;

	if (!postbr) {
		return 0;
	}
	postbrlen = strlen(postbr);
	for (i = 0; i < postbrlen; i++) {
		if (postbr[i] == '\t') {
			postbrreallen += 8 - (postbrreallen % 8);
		} else {
			postbrreallen++;
		}
	}
	return postbrreallen;
}

/*! \internal
 *  \brief Setup postbr to be used while wrapping the text.
 *         Add to postbr array all the spaces and tabs at the beginning of text.
 *  \param postbr output array.
 *  \param len text array length.
 *  \param text Text with format string before the actual string.
 */
static void xmldoc_setpostbr(char *postbr, size_t len, const char *text)
{
	int c, postbrlen = 0;

	if (!text) {
		return;
	}

	for (c = 0; c < len; c++) {
		if (text[c] == '\t' || text[c] == ' ') {
			postbr[postbrlen++] = text[c];
		} else {
			break;
		}
	}
	postbr[postbrlen] = '\0';
}

/*! \internal
 *  \brief Try to find a space or a break in text starting at currentpost
 *         and moving at most maxdiff positions.
 *         Helper for xmldoc_string_wrap().
 *  \param text Input string where it will search.
 *  \param currentpos Current position within text.
 *  \param maxdiff Not move more than maxdiff inside text.
 *  \retval 1 if a space or break is found inside text while moving.
 *  \retval 0 if no space or break is found.
 */
static int xmldoc_wait_nextspace(const char *text, int currentpos, int maxdiff)
{
	int i, textlen;

	if (!text) {
		return 0;
	}

	textlen = strlen(text);
	for (i = currentpos; i < textlen; i++) {
		if (text[i] == ESC) {
			/* Move to the end of the escape sequence */
			while (i < textlen && text[i] != 'm') {
				i++;
			}
		} else if (text[i] == ' ' || text[i] == '\n') {
			/* Found the next space or linefeed */
			return 1;
		} else if (i - currentpos > maxdiff) {
			/* We have looked the max distance and didn't find it */
			return 0;
		}
	}

	/* Reached the end and did not find it */

	return 0;
}

/*! \internal
 *  \brief Helper function for xmldoc_string_wrap().
 *	   Try to found a space or a break inside text moving backward
 *	   not more than maxdiff positions.
 *  \param text The input string where to search for a space.
 *  \param currentpos The current cursor position.
 *  \param maxdiff The max number of positions to move within text.
 *  \retval 0 If no space is found (Notice that text[currentpos] is not a space or a break)
 *  \retval > 0 If a space or a break is found, and the result is the position relative to
 *		currentpos.
 */
static int xmldoc_foundspace_backward(const char *text, int currentpos, int maxdiff)
{
	int i;

	for (i = currentpos; i > 0; i--) {
		if (text[i] == ' ' || text[i] == '\n') {
			return (currentpos - i);
		} else if (text[i] == 'm' && (text[i - 1] >= '0' || text[i - 1] <= '9')) {
			/* give up, we found the end of a possible ESC sequence. */
			return 0;
		} else if (currentpos - i > maxdiff) {
			/* give up, we can't move anymore. */
			return 0;
		}
	}

	/* we found the beginning of the text */

	return 0;
}

/*! \internal
 *  \brief Justify a text to a number of columns.
 *  \param text Input text to be justified.
 *  \param columns Number of columns to preserve in the text.
 *  \param maxdiff Try to not cut a word when goinf down.
 *  \retval NULL on error.
 *  \retval The wrapped text.
 */
static char *xmldoc_string_wrap(const char *text, int columns, int maxdiff)
{
	struct ast_str *tmp;
	char *ret, postbr[160];
	int count = 1, i, backspace, needtobreak = 0, colmax, textlen;

	/* sanity check */
	if (!text || columns <= 0 || maxdiff < 0) {
		ast_log(LOG_WARNING, "Passing wrong arguments while trying to wrap the text\n");
		return NULL;
	}

	tmp = ast_str_create(strlen(text) * 3);

	if (!tmp) {
		return NULL;
	}

	/* Check for blanks and tabs and put them in postbr. */
	xmldoc_setpostbr(postbr, sizeof(postbr), text);
	colmax = columns - xmldoc_postbrlen(postbr);

	textlen = strlen(text);
	for (i = 0; i < textlen; i++) {
		if (needtobreak || !(count % colmax)) {
			if (text[i] == ' ') {
				ast_str_append(&tmp, 0, "\n%s", postbr);
				needtobreak = 0;
				count = 1;
			} else if (text[i] != '\n') {
				needtobreak = 1;
				if (xmldoc_wait_nextspace(text, i, maxdiff)) {
					/* wait for the next space */
					ast_str_append(&tmp, 0, "%c", text[i]);
					continue;
				}
				/* Try to look backwards */
				backspace = xmldoc_foundspace_backward(text, i, maxdiff);
				if (backspace) {
					needtobreak = 1;
					ast_str_truncate(tmp, -backspace);
					i -= backspace + 1;
					continue;
				}
				ast_str_append(&tmp, 0, "\n%s", postbr);
				needtobreak = 0;
				count = 1;
			}
			/* skip blanks after a \n */
			while (text[i] == ' ') {
				i++;
			}
		}
		if (text[i] == '\n') {
			xmldoc_setpostbr(postbr, sizeof(postbr), &text[i] + 1);
			colmax = columns - xmldoc_postbrlen(postbr);
			needtobreak = 0;
			count = 1;
		}
		if (text[i] == ESC) {
			/* Ignore Escape sequences. */
			do {
				ast_str_append(&tmp, 0, "%c", text[i]);
				i++;
			} while (i < textlen && text[i] != 'm');
		} else {
			count++;
		}
		ast_str_append(&tmp, 0, "%c", text[i]);
	}

	ret = ast_strdup(ast_str_buffer(tmp));
	ast_free(tmp);

	return ret;
}

char *ast_xmldoc_printable(const char *bwinput, int withcolors)
{
	struct ast_str *colorized;
	char *wrapped = NULL;
	int i, c, len, colorsection;
	char *tmp;
	size_t bwinputlen;
	static const int base_fg = COLOR_CYAN;

	if (!bwinput) {
		return NULL;
	}

	bwinputlen = strlen(bwinput);

	if (!(colorized = ast_str_create(256))) {
		return NULL;
	}

	if (withcolors) {
		ast_term_color_code(&colorized, base_fg, 0);
		if (!colorized) {
			return NULL;
		}
	}

	for (i = 0; i < bwinputlen; i++) {
		colorsection = 0;
		/* Check if we are at the beginning of a tag to be colorized. */
		for (c = 0; c < ARRAY_LEN(colorized_tags); c++) {
			if (strncasecmp(bwinput + i, colorized_tags[c].inittag, strlen(colorized_tags[c].inittag))) {
				continue;
			}

			if (!(tmp = strcasestr(bwinput + i + strlen(colorized_tags[c].inittag), colorized_tags[c].endtag))) {
				continue;
			}

			len = tmp - (bwinput + i + strlen(colorized_tags[c].inittag));

			/* Setup color */
			if (withcolors) {
				ast_term_color_code(&colorized, colorized_tags[c].colorfg, 0);
				if (!colorized) {
					return NULL;
				}
			}

			/* copy initial string replace */
			ast_str_append(&colorized, 0, "%s", colorized_tags[c].init);
			if (!colorized) {
				return NULL;
			}
			{
				char buf[len + 1];
				ast_copy_string(buf, bwinput + i + strlen(colorized_tags[c].inittag), sizeof(buf));
				ast_str_append(&colorized, 0, "%s", buf);
			}
			if (!colorized) {
				return NULL;
			}

			/* copy the ending string replace */
			ast_str_append(&colorized, 0, "%s", colorized_tags[c].end);
			if (!colorized) {
				return NULL;
			}

			/* Continue with the last color. */
			if (withcolors) {
				ast_term_color_code(&colorized, base_fg, 0);
				if (!colorized) {
					return NULL;
				}
			}

			i += len + strlen(colorized_tags[c].endtag) + strlen(colorized_tags[c].inittag) - 1;
			colorsection = 1;
			break;
		}

		if (!colorsection) {
			ast_str_append(&colorized, 0, "%c", bwinput[i]);
			if (!colorized) {
				return NULL;
			}
		}
	}

	if (withcolors) {
		ast_str_append(&colorized, 0, "%s", term_end());
		if (!colorized) {
			return NULL;
		}
	}

	/* Wrap the text, notice that string wrap will avoid cutting an ESC sequence. */
	wrapped = xmldoc_string_wrap(ast_str_buffer(colorized), xmldoc_text_columns, xmldoc_max_diff);

	ast_free(colorized);

	return wrapped;
}

/*! \internal
 *  \brief Cleanup spaces and tabs after a \n
 *  \param text String to be cleaned up.
 *  \param output buffer (not already allocated).
 *  \param lastspaces Remove last spaces in the string.
 */
static void xmldoc_string_cleanup(const char *text, struct ast_str **output, int lastspaces)
{
	int i;
	size_t textlen;

	if (!text) {
		*output = NULL;
		return;
	}

	textlen = strlen(text);

	*output = ast_str_create(textlen);
	if (!(*output)) {
		ast_log(LOG_ERROR, "Problem allocating output buffer\n");
		return;
	}

	for (i = 0; i < textlen; i++) {
		if (text[i] == '\n' || text[i] == '\r') {
			/* remove spaces/tabs/\n after a \n. */
			while (text[i + 1] == '\t' || text[i + 1] == '\r' || text[i + 1] == '\n') {
				i++;
			}
			ast_str_append(output, 0, " ");
			continue;
		} else {
			ast_str_append(output, 0, "%c", text[i]);
		}
	}

	/* remove last spaces (we don't want always to remove the trailing spaces). */
	if (lastspaces) {
		ast_str_trim_blanks(*output);
	}
}

/*! \internal
 *  \brief Get the application/function node for 'name' application/function with language 'language'
 *         if we don't find any, get the first application with 'name' no matter which language with.
 *  \param type 'application', 'function', ...
 *  \param name Application or Function name.
 *  \param language Try to get this language (if not found try with en_US)
 *  \retval NULL on error.
 *  \retval A node of type ast_xml_node.
 */
static struct ast_xml_node *xmldoc_get_node(const char *type, const char *name, const char *language)
{
	struct ast_xml_node *node = NULL;
	struct documentation_tree *doctree;
	const char *lang;

	AST_RWLIST_RDLOCK(&xmldoc_tree);
	AST_LIST_TRAVERSE(&xmldoc_tree, doctree, entry) {
		/* the core xml documents have priority over thirdparty document. */
		node = ast_xml_get_root(doctree->doc);
		while ((node = ast_xml_find_element(node, type, "name", name))) {
			/* Check language */
			lang = ast_xml_get_attribute(node, "language");
			if (lang && !strcmp(lang, language)) {
				ast_xml_free_attr(lang);
				break;
			} else if (lang) {
				ast_xml_free_attr(lang);
			}
		}

		if (node && ast_xml_node_get_children(node)) {
			break;
		}

		/* We didn't find the application documentation for the specified language,
		so, try to load documentation for any language */
		node = ast_xml_get_root(doctree->doc);
		if (ast_xml_node_get_children(node)) {
			if ((node = ast_xml_find_element(ast_xml_node_get_children(node), type, "name", name))) {
				break;
			}
		}
	}
	AST_RWLIST_UNLOCK(&xmldoc_tree);

	return node;
}

/*! \internal
 *  \brief Helper function used to build the syntax, it allocates the needed buffer (or reallocates it),
 *         and based on the reverse value it makes use of fmt to print the parameter list inside the
 *         realloced buffer (syntax).
 *  \param reverse We are going backwards while generating the syntax?
 *  \param len Current length of 'syntax' buffer.
 *  \param syntax Output buffer for the concatenated values.
 *  \param fmt A format string that will be used in a sprintf call.
 */
static void __attribute__((format(printf, 4, 5))) xmldoc_reverse_helper(int reverse, int *len, char **syntax, const char *fmt, ...)
{
	int totlen, tmpfmtlen;
	char *tmpfmt, tmp;
	va_list ap;

	va_start(ap, fmt);
	if (ast_vasprintf(&tmpfmt, fmt, ap) < 0) {
		va_end(ap);
		return;
	}
	va_end(ap);

	tmpfmtlen = strlen(tmpfmt);
	totlen = *len + tmpfmtlen + 1;

	*syntax = ast_realloc(*syntax, totlen);

	if (!*syntax) {
		ast_free(tmpfmt);
		return;
	}

	if (reverse) {
		memmove(*syntax + tmpfmtlen, *syntax, *len);
		/* Save this char, it will be overwritten by the \0 of strcpy. */
		tmp = (*syntax)[0];
		strcpy(*syntax, tmpfmt);
		/* Restore the already saved char. */
		(*syntax)[tmpfmtlen] = tmp;
		(*syntax)[totlen - 1] = '\0';
	} else {
		strcpy(*syntax + *len, tmpfmt);
	}

	*len = totlen - 1;
	ast_free(tmpfmt);
}

/*! \internal
 *  \brief Check if the passed node has 'what' tags inside it.
 *  \param node Root node to search 'what' elements.
 *  \param what node name to search inside node.
 *  \retval 1 If a 'what' element is found inside 'node'.
 *  \retval 0 If no 'what' is found inside 'node'.
 */
static int xmldoc_has_inside(struct ast_xml_node *fixnode, const char *what)
{
	struct ast_xml_node *node = fixnode;

	for (node = ast_xml_node_get_children(fixnode); node; node = ast_xml_node_get_next(node)) {
		if (!strcasecmp(ast_xml_node_get_name(node), what)) {
			return 1;
		}
	}
	return 0;
}

/*! \internal
 *  \brief Check if the passed node has at least one node inside it.
 *  \param node Root node to search node elements.
 *  \retval 1 If a node element is found inside 'node'.
 *  \retval 0 If no node is found inside 'node'.
 */
static int xmldoc_has_nodes(struct ast_xml_node *fixnode)
{
	struct ast_xml_node *node = fixnode;

	for (node = ast_xml_node_get_children(fixnode); node; node = ast_xml_node_get_next(node)) {
		if (strcasecmp(ast_xml_node_get_name(node), "text")) {
			return 1;
		}
	}
	return 0;
}

/*! \internal
 *  \brief Check if the passed node has at least one specialtag.
 *  \param node Root node to search "specialtags" elements.
 *  \retval 1 If a "specialtag" element is found inside 'node'.
 *  \retval 0 If no "specialtag" is found inside 'node'.
 */
static int xmldoc_has_specialtags(struct ast_xml_node *fixnode)
{
	struct ast_xml_node *node = fixnode;
	int i;

	for (node = ast_xml_node_get_children(fixnode); node; node = ast_xml_node_get_next(node)) {
		for (i = 0; i < ARRAY_LEN(special_tags); i++) {
			if (!strcasecmp(ast_xml_node_get_name(node), special_tags[i].tagname)) {
				return 1;
			}
		}
	}
	return 0;
}

/*! \internal
 *  \brief Build the syntax for a specified starting node.
 *  \param rootnode A pointer to the ast_xml root node.
 *  \param rootname Name of the application, function, option, etc. to build the syntax.
 *  \param childname The name of each parameter node.
 *  \param printparenthesis Boolean if we must print parenthesis if not parameters are found in the rootnode.
 *  \param printrootname Boolean if we must print the rootname before the syntax and parenthesis at the begining/end.
 *  \retval NULL on error.
 *  \retval An ast_malloc'ed string with the syntax generated.
 */
static char *xmldoc_get_syntax_fun(struct ast_xml_node *rootnode, const char *rootname, const char *childname, int printparenthesis, int printrootname)
{
#define GOTONEXT(__rev, __a) (__rev ? ast_xml_node_get_prev(__a) : ast_xml_node_get_next(__a))
#define ISLAST(__rev, __a)  (__rev == 1 ? (ast_xml_node_get_prev(__a) ? 0 : 1) : (ast_xml_node_get_next(__a) ? 0 : 1))
#define MP(__a) ((multiple ? __a : ""))
	struct ast_xml_node *node = NULL, *firstparam = NULL, *lastparam = NULL;
	const char *paramtype, *multipletype, *paramnameattr, *attrargsep, *parenthesis, *argname;
	int reverse, required, paramcount = 0, openbrackets = 0, len = 0, hasparams=0;
	int reqfinode = 0, reqlanode = 0, optmidnode = 0, prnparenthesis, multiple;
	char *syntax = NULL, *argsep, *paramname;

	if (ast_strlen_zero(rootname) || ast_strlen_zero(childname)) {
		ast_log(LOG_WARNING, "Tried to look in XML tree with faulty rootname or childname while creating a syntax.\n");
		return NULL;
	}

	if (!rootnode || !ast_xml_node_get_children(rootnode)) {
		/* If the rootnode field is not found, at least print name. */
		ast_asprintf(&syntax, "%s%s", (printrootname ? rootname : ""), (printparenthesis ? "()" : ""));
		return syntax;
	}

	/* Get the argument separator from the root node attribute name 'argsep', if not found
	defaults to ','. */
	attrargsep = ast_xml_get_attribute(rootnode, "argsep");
	if (attrargsep) {
		argsep = ast_strdupa(attrargsep);
		ast_xml_free_attr(attrargsep);
	} else {
		argsep = ast_strdupa(",");
	}

	/* Get order of evaluation. */
	for (node = ast_xml_node_get_children(rootnode); node; node = ast_xml_node_get_next(node)) {
		if (strcasecmp(ast_xml_node_get_name(node), childname)) {
			continue;
		}
		required = 0;
		hasparams = 1;
		if ((paramtype = ast_xml_get_attribute(node, "required"))) {
			if (ast_true(paramtype)) {
				required = 1;
			}
			ast_xml_free_attr(paramtype);
		}

		lastparam = node;
		reqlanode = required;

		if (!firstparam) {
			/* first parameter node */
			firstparam = node;
			reqfinode = required;
		}
	}

	if (!hasparams) {
		/* This application, function, option, etc, doesn't have any params. */
		ast_asprintf(&syntax, "%s%s", (printrootname ? rootname : ""), (printparenthesis ? "()" : ""));
		return syntax;
	}

	if (reqfinode && reqlanode) {
		/* check midnode */
		for (node = ast_xml_node_get_children(rootnode); node; node = ast_xml_node_get_next(node)) {
			if (strcasecmp(ast_xml_node_get_name(node), childname)) {
				continue;
			}
			if (node != firstparam && node != lastparam) {
				if ((paramtype = ast_xml_get_attribute(node, "required"))) {
					if (!ast_true(paramtype)) {
						optmidnode = 1;
						break;
					}
					ast_xml_free_attr(paramtype);
				}
			}
		}
	}

	if ((!reqfinode && reqlanode) || (reqfinode && reqlanode && optmidnode)) {
		reverse = 1;
		node = lastparam;
	} else {
		reverse = 0;
		node = firstparam;
	}

	/* init syntax string. */
	if (reverse) {
		xmldoc_reverse_helper(reverse, &len, &syntax,
			(printrootname ? (printrootname == 2 ? ")]" : ")"): ""));
	} else {
		xmldoc_reverse_helper(reverse, &len, &syntax, "%s%s", (printrootname ? rootname : ""),
			(printrootname ? (printrootname == 2 ? "[(" : "(") : ""));
	}

	for (; node; node = GOTONEXT(reverse, node)) {
		if (strcasecmp(ast_xml_node_get_name(node), childname)) {
			continue;
		}

		/* Get the argument name, if it is not the leaf, go inside that parameter. */
		if (xmldoc_has_inside(node, "argument")) {
			parenthesis = ast_xml_get_attribute(node, "hasparams");
			prnparenthesis = 0;
			if (parenthesis) {
				prnparenthesis = ast_true(parenthesis);
				if (!strcasecmp(parenthesis, "optional")) {
					prnparenthesis = 2;
				}
				ast_xml_free_attr(parenthesis);
			}
			argname = ast_xml_get_attribute(node, "name");
			if (argname) {
				paramname = xmldoc_get_syntax_fun(node, argname, "argument", prnparenthesis, prnparenthesis);
				ast_xml_free_attr(argname);
			} else {
				/* Malformed XML, print **UNKOWN** */
				paramname = ast_strdup("**unknown**");
			}
		} else {
			paramnameattr = ast_xml_get_attribute(node, "name");
			if (!paramnameattr) {
				ast_log(LOG_WARNING, "Malformed XML %s: no %s name\n", rootname, childname);
				if (syntax) {
					/* Free already allocated syntax */
					ast_free(syntax);
				}
				/* to give up is ok? */
				ast_asprintf(&syntax, "%s%s", (printrootname ? rootname : ""), (printparenthesis ? "()" : ""));
				return syntax;
			}
			paramname = ast_strdup(paramnameattr);
			ast_xml_free_attr(paramnameattr);
		}

		/* Defaults to 'false'. */
		multiple = 0;
		if ((multipletype = ast_xml_get_attribute(node, "multiple"))) {
			if (ast_true(multipletype)) {
				multiple = 1;
			}
			ast_xml_free_attr(multipletype);
		}

		required = 0;	/* Defaults to 'false'. */
		if ((paramtype = ast_xml_get_attribute(node, "required"))) {
			if (ast_true(paramtype)) {
				required = 1;
			}
			ast_xml_free_attr(paramtype);
		}

		/* build syntax core. */

		if (required) {
			/* First parameter */
			if (!paramcount) {
				xmldoc_reverse_helper(reverse, &len, &syntax, "%s%s%s%s", paramname, MP("["), MP(argsep), MP("...]"));
			} else {
				/* Time to close open brackets. */
				while (openbrackets > 0) {
					xmldoc_reverse_helper(reverse, &len, &syntax, (reverse ? "[" : "]"));
					openbrackets--;
				}
				if (reverse) {
					xmldoc_reverse_helper(reverse, &len, &syntax, "%s%s", paramname, argsep);
				} else {
					xmldoc_reverse_helper(reverse, &len, &syntax, "%s%s", argsep, paramname);
				}
				xmldoc_reverse_helper(reverse, &len, &syntax, "%s%s%s", MP("["), MP(argsep), MP("...]"));
			}
		} else {
			/* First parameter */
			if (!paramcount) {
				xmldoc_reverse_helper(reverse, &len, &syntax, "[%s%s%s%s]", paramname, MP("["), MP(argsep), MP("...]"));
			} else {
				if (ISLAST(reverse, node)) {
					/* This is the last parameter. */
					if (reverse) {
						xmldoc_reverse_helper(reverse, &len, &syntax, "[%s%s%s%s]%s", paramname,
									MP("["), MP(argsep), MP("...]"), argsep);
					} else {
						xmldoc_reverse_helper(reverse, &len, &syntax, "%s[%s%s%s%s]", argsep, paramname,
									MP("["), MP(argsep), MP("...]"));
					}
				} else {
					if (reverse) {
						xmldoc_reverse_helper(reverse, &len, &syntax, "%s%s%s%s%s]", paramname, argsep,
									MP("["), MP(argsep), MP("...]"));
					} else {
						xmldoc_reverse_helper(reverse, &len, &syntax, "[%s%s%s%s%s", argsep, paramname,
									MP("["), MP(argsep), MP("...]"));
					}
					openbrackets++;
				}
			}
		}
		ast_free(paramname);

		paramcount++;
	}

	/* Time to close open brackets. */
	while (openbrackets > 0) {
		xmldoc_reverse_helper(reverse, &len, &syntax, (reverse ? "[" : "]"));
		openbrackets--;
	}

	/* close syntax string. */
	if (reverse) {
		xmldoc_reverse_helper(reverse, &len, &syntax, "%s%s", (printrootname ? rootname : ""),
			(printrootname ? (printrootname == 2 ? "[(" : "(") : ""));
	} else {
		xmldoc_reverse_helper(reverse, &len, &syntax, (printrootname ? (printrootname == 2 ? ")]" : ")") : ""));
	}

	return syntax;
#undef ISLAST
#undef GOTONEXT
#undef MP
}

/*! \internal
 *  \brief Parse an enumlist inside a <parameter> to generate a COMMAND
 *         syntax.
 *  \param fixnode A pointer to the <enumlist> node.
 *  \retval {<unknown>} on error.
 *  \retval A string inside brackets {} with the enum's separated by pipes |.
 */
static char *xmldoc_parse_cmd_enumlist(struct ast_xml_node *fixnode)
{
	struct ast_xml_node *node = fixnode;
	struct ast_str *paramname;
	char *enumname, *ret;
	int first = 1;

	paramname = ast_str_create(128);
	if (!paramname) {
		return ast_strdup("{<unkown>}");
	}

	ast_str_append(&paramname, 0, "{");

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (strcasecmp(ast_xml_node_get_name(node), "enum")) {
			continue;
		}

		enumname = xmldoc_get_syntax_cmd(node, "", 0);
		if (!enumname) {
			continue;
		}
		if (!first) {
			ast_str_append(&paramname, 0, "|");
		}
		ast_str_append(&paramname, 0, "%s", enumname);
		first = 0;
		ast_free(enumname);
	}

	ast_str_append(&paramname, 0, "}");

	ret = ast_strdup(ast_str_buffer(paramname));
	ast_free(paramname);

	return ret;
}

/*! \internal
 *  \brief Generate a syntax of COMMAND type.
 *  \param fixnode The <syntax> node pointer.
 *  \param name The name of the 'command'.
 *  \param printname Print the name of the command before the paramters?
 *  \retval On error, return just 'name'.
 *  \retval On success return the generated syntax.
 */
static char *xmldoc_get_syntax_cmd(struct ast_xml_node *fixnode, const char *name, int printname)
{
	struct ast_str *syntax;
	struct ast_xml_node *tmpnode, *node = fixnode;
	char *ret, *paramname;
	const char *paramtype, *attrname, *literal;
	int required, isenum, first = 1, isliteral;

	syntax = ast_str_create(128);
	if (!syntax) {
		/* at least try to return something... */
		return ast_strdup(name);
	}

	/* append name to output string. */
	if (printname) {
		ast_str_append(&syntax, 0, "%s", name);
		first = 0;
	}

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (strcasecmp(ast_xml_node_get_name(node), "parameter")) {
			continue;
		}

		if (xmldoc_has_inside(node, "parameter")) {
			/* is this a recursive parameter. */
			paramname = xmldoc_get_syntax_cmd(node, "", 0);
			isenum = 1;
		} else if (!xmldoc_has_inside(node, "enumlist")) {
			/* this is a simple parameter. */
			attrname = ast_xml_get_attribute(node, "name");
			if (!attrname) {
				/* ignore this bogus parameter and continue. */
				continue;
			}
			paramname = ast_strdup(attrname);
			ast_xml_free_attr(attrname);
			isenum = 0;
		} else {
			/* parse enumlist (note that this is a special enumlist
			that is used to describe a syntax like {<param1>|<param2>|...} */
			for (tmpnode = ast_xml_node_get_children(node); tmpnode; tmpnode = ast_xml_node_get_next(tmpnode)) {
				if (!strcasecmp(ast_xml_node_get_name(tmpnode), "enumlist")) {
					break;
				}
			}
			paramname = xmldoc_parse_cmd_enumlist(tmpnode);
			isenum = 1;
		}

		/* Is this parameter required? */
		required = 0;
		paramtype = ast_xml_get_attribute(node, "required");
		if (paramtype) {
			required = ast_true(paramtype);
			ast_xml_free_attr(paramtype);
		}

		/* Is this a replaceable value or a fixed parameter value? */
		isliteral = 0;
		literal = ast_xml_get_attribute(node, "literal");
		if (literal) {
			isliteral = ast_true(literal);
			ast_xml_free_attr(literal);
		}

		/* if required="false" print with [...].
		 * if literal="true" or is enum print without <..>.
		 * if not first print a space at the beginning.
		 */
		ast_str_append(&syntax, 0, "%s%s%s%s%s%s",
				(first ? "" : " "),
				(required ? "" : "["),
				(isenum || isliteral ? "" : "<"),
				paramname,
				(isenum || isliteral ? "" : ">"),
				(required ? "" : "]"));
		first = 0;
		ast_free(paramname);
	}

	/* return a common string. */
	ret = ast_strdup(ast_str_buffer(syntax));
	ast_free(syntax);

	return ret;
}

/*! \internal
 *  \brief Generate an AMI action syntax.
 *  \param fixnode The manager action node pointer.
 *  \param name The name of the manager action.
 *  \retval The generated syntax.
 *  \retval NULL on error.
 */
static char *xmldoc_get_syntax_manager(struct ast_xml_node *fixnode, const char *name)
{
	struct ast_str *syntax;
	struct ast_xml_node *node = fixnode;
	const char *paramtype, *attrname;
	int required;
	char *ret;

	syntax = ast_str_create(128);
	if (!syntax) {
		return ast_strdup(name);
	}

	ast_str_append(&syntax, 0, "Action: %s", name);

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (strcasecmp(ast_xml_node_get_name(node), "parameter")) {
			continue;
		}

		/* Is this parameter required? */
		required = 0;
		paramtype = ast_xml_get_attribute(node, "required");
		if (paramtype) {
			required = ast_true(paramtype);
			ast_xml_free_attr(paramtype);
		}

		attrname = ast_xml_get_attribute(node, "name");
		if (!attrname) {
			/* ignore this bogus parameter and continue. */
			continue;
		}

		ast_str_append(&syntax, 0, "\n%s%s:%s <value>",
			(required ? "" : "["),
			attrname,
			(required ? "" : "]"));

		ast_xml_free_attr(attrname);
	}

	/* return a common string. */
	ret = ast_strdup(ast_str_buffer(syntax));
	ast_free(syntax);

	return ret;
}

/*! \brief Types of syntax that we are able to generate. */
enum syntaxtype {
	FUNCTION_SYNTAX,
	MANAGER_SYNTAX,
	COMMAND_SYNTAX
};

/*! \brief Mapping between type of node and type of syntax to generate. */
static struct strsyntaxtype {
	const char *type;
	enum syntaxtype stxtype;
} stxtype[] = {
	{ "function",		FUNCTION_SYNTAX	},
	{ "application",	FUNCTION_SYNTAX	},
	{ "manager",		MANAGER_SYNTAX  },
	{ "agi",		COMMAND_SYNTAX	}
};

/*! \internal
 *  \brief Get syntax type based on type of node.
 *  \param type Type of node.
 *  \retval The type of syntax to generate based on the type of node.
 */
static enum syntaxtype xmldoc_get_syntax_type(const char *type)
{
	int i;
	for (i=0; i < ARRAY_LEN(stxtype); i++) {
		if (!strcasecmp(stxtype[i].type, type)) {
			return stxtype[i].stxtype;
		}
	}

	return FUNCTION_SYNTAX;
}

char *ast_xmldoc_build_syntax(const char *type, const char *name)
{
	struct ast_xml_node *node;
	char *syntax = NULL;

	node = xmldoc_get_node(type, name, documentation_language);
	if (!node) {
		return NULL;
	}

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (!strcasecmp(ast_xml_node_get_name(node), "syntax")) {
			break;
		}
	}

	if (node) {
		switch (xmldoc_get_syntax_type(type)) {
		case FUNCTION_SYNTAX:
			syntax = xmldoc_get_syntax_fun(node, name, "parameter", 1, 1);
			break;
		case COMMAND_SYNTAX:
			syntax = xmldoc_get_syntax_cmd(node, name, 1);
			break;
		case MANAGER_SYNTAX:
			syntax = xmldoc_get_syntax_manager(node, name);
			break;
		default:
			syntax = xmldoc_get_syntax_fun(node, name, "parameter", 1, 1);
		}
	}
	return syntax;
}

/*! \internal
 *  \brief Parse a <para> element.
 *  \param node The <para> element pointer.
 *  \param tabs Added this string before the content of the <para> element.
 *  \param posttabs Added this string after the content of the <para> element.
 *  \param buffer This must be an already allocated ast_str. It will be used
 *         to store the result (if already has something it will be appended to the current
 *         string).
 *  \retval 1 If 'node' is a named 'para'.
 *  \retval 2 If data is appended in buffer.
 *  \retval 0 on error.
 */
static int xmldoc_parse_para(struct ast_xml_node *node, const char *tabs, const char *posttabs, struct ast_str **buffer)
{
	const char *tmptext;
	struct ast_xml_node *tmp;
	int ret = 0;
	struct ast_str *tmpstr;

	if (!node || !ast_xml_node_get_children(node)) {
		return ret;
	}

	if (strcasecmp(ast_xml_node_get_name(node), "para")) {
		return ret;
	}

	ast_str_append(buffer, 0, "%s", tabs);

	ret = 1;

	for (tmp = ast_xml_node_get_children(node); tmp; tmp = ast_xml_node_get_next(tmp)) {
		/* Get the text inside the <para> element and append it to buffer. */
		tmptext = ast_xml_get_text(tmp);
		if (tmptext) {
			/* Strip \n etc. */
			xmldoc_string_cleanup(tmptext, &tmpstr, 0);
			ast_xml_free_text(tmptext);
			if (tmpstr) {
				if (strcasecmp(ast_xml_node_get_name(tmp), "text")) {
					ast_str_append(buffer, 0, "<%s>%s</%s>", ast_xml_node_get_name(tmp),
							ast_str_buffer(tmpstr), ast_xml_node_get_name(tmp));
				} else {
					ast_str_append(buffer, 0, "%s", ast_str_buffer(tmpstr));
				}
				ast_free(tmpstr);
				ret = 2;
			}
		}
	}

	ast_str_append(buffer, 0, "%s", posttabs);

	return ret;
}

/*! \internal
 *  \brief Parse special elements defined in 'struct special_tags' special elements must have a <para> element inside them.
 *  \param fixnode special tag node pointer.
 *  \param tabs put tabs before printing the node content.
 *  \param posttabs put posttabs after printing node content.
 *  \param buffer Output buffer, the special tags will be appended here.
 *  \retval 0 if no special element is parsed.
 *  \retval 1 if a special element is parsed (data is appended to buffer).
 *  \retval 2 if a special element is parsed and also a <para> element is parsed inside the specialtag.
 */
static int xmldoc_parse_specialtags(struct ast_xml_node *fixnode, const char *tabs, const char *posttabs, struct ast_str **buffer)
{
	struct ast_xml_node *node = fixnode;
	int ret = 0, i, count = 0;

	if (!node || !ast_xml_node_get_children(node)) {
		return ret;
	}

	for (i = 0; i < ARRAY_LEN(special_tags); i++) {
		if (strcasecmp(ast_xml_node_get_name(node), special_tags[i].tagname)) {
			continue;
		}

		ret = 1;
		/* This is a special tag. */

		/* concat data */
		if (!ast_strlen_zero(special_tags[i].init)) {
			ast_str_append(buffer, 0, "%s%s", tabs, special_tags[i].init);
		}

		/* parse <para> elements inside special tags. */
		for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
			/* first <para> just print it without tabs at the begining. */
			if (xmldoc_parse_para(node, (!count ? "" : tabs), posttabs, buffer) == 2) {
				ret = 2;
			}
		}

		if (!ast_strlen_zero(special_tags[i].end)) {
			ast_str_append(buffer, 0, "%s%s", special_tags[i].end, posttabs);
		}

		break;
	}

	return ret;
}

/*! \internal
 *  \brief Parse an <argument> element from the xml documentation.
 *  \param fixnode Pointer to the 'argument' xml node.
 *  \param insideparameter If we are parsing an <argument> inside a <parameter>.
 *  \param paramtabs pre tabs if we are inside a parameter element.
 *  \param tabs What to be printed before the argument name.
 *  \param buffer Output buffer to put values found inside the <argument> element.
 *  \retval 1 If there is content inside the argument.
 *  \retval 0 If the argument element is not parsed, or there is no content inside it.
 */
static int xmldoc_parse_argument(struct ast_xml_node *fixnode, int insideparameter, const char *paramtabs, const char *tabs, struct ast_str **buffer)
{
	struct ast_xml_node *node = fixnode;
	const char *argname;
	int count = 0, ret = 0;

	if (!node || !ast_xml_node_get_children(node)) {
		return ret;
	}

	/* Print the argument names */
	argname = ast_xml_get_attribute(node, "name");
	if (!argname) {
		return 0;
	}
	if (xmldoc_has_inside(node, "para") || xmldoc_has_specialtags(node)) {
		ast_str_append(buffer, 0, "%s%s%s", tabs, argname, (insideparameter ? "\n" : ""));
		ast_xml_free_attr(argname);
	} else {
		ast_xml_free_attr(argname);
		return 0;
	}

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (xmldoc_parse_para(node, (insideparameter ? paramtabs : (!count ? " - " : tabs)), "\n", buffer) == 2) {
			count++;
			ret = 1;
		} else if (xmldoc_parse_specialtags(node, (insideparameter ? paramtabs : (!count ? " - " : tabs)), "\n", buffer) == 2) {
			count++;
			ret = 1;
		}
	}

	return ret;
}

/*! \internal
 *  \brief Parse a <variable> node inside a <variablelist> node.
 *  \param node The variable node to parse.
 *  \param tabs A string to be appended at the begining of the output that will be stored
 *         in buffer.
 *  \param buffer This must be an already created ast_str. It will be used
 *         to store the result (if already has something it will be appended to the current
 *         string).
 *  \retval 0 if no data is appended.
 *  \retval 1 if data is appended.
 */
static int xmldoc_parse_variable(struct ast_xml_node *node, const char *tabs, struct ast_str **buffer)
{
	struct ast_xml_node *tmp;
	const char *valname;
	const char *tmptext;
	struct ast_str *cleanstr;
	int ret = 0, printedpara=0;

	for (tmp = ast_xml_node_get_children(node); tmp; tmp = ast_xml_node_get_next(tmp)) {
		if (xmldoc_parse_para(tmp, (ret ? tabs : ""), "\n", buffer)) {
			printedpara = 1;
			continue;
		} else if (xmldoc_parse_specialtags(tmp, (ret ? tabs : ""), "\n", buffer)) {
			printedpara = 1;
			continue;
		}

		if (strcasecmp(ast_xml_node_get_name(tmp), "value")) {
			continue;
		}

		/* Parse a <value> tag only. */
		if (!printedpara) {
			ast_str_append(buffer, 0, "\n");
			printedpara = 1;
		}
		/* Parse each <value name='valuename'>desciption</value> */
		valname = ast_xml_get_attribute(tmp, "name");
		if (valname) {
			ret = 1;
			ast_str_append(buffer, 0, "%s<value>%s</value>", tabs, valname);
			ast_xml_free_attr(valname);
		}
		tmptext = ast_xml_get_text(tmp);
		/* Check inside this node for any explanation about its meaning. */
		if (tmptext) {
			/* Cleanup text. */
			xmldoc_string_cleanup(tmptext, &cleanstr, 1);
			ast_xml_free_text(tmptext);
			if (cleanstr && ast_str_strlen(cleanstr) > 0) {
				ast_str_append(buffer, 0, ":%s", ast_str_buffer(cleanstr));
			}
			ast_free(cleanstr);
		}
		ast_str_append(buffer, 0, "\n");
	}

	return ret;
}

/*! \internal
 *  \brief Parse a <variablelist> node and put all the output inside 'buffer'.
 *  \param node The variablelist node pointer.
 *  \param tabs A string to be appended at the begining of the output that will be stored
 *         in buffer.
 *  \param buffer This must be an already created ast_str. It will be used
 *         to store the result (if already has something it will be appended to the current
 *         string).
 *  \retval 1 If a <variablelist> element is parsed.
 *  \retval 0 On error.
 */
static int xmldoc_parse_variablelist(struct ast_xml_node *node, const char *tabs, struct ast_str **buffer)
{
	struct ast_xml_node *tmp;
	const char *varname;
	char *vartabs;
	int ret = 0;

	if (!node || !ast_xml_node_get_children(node)) {
		return ret;
	}

	if (strcasecmp(ast_xml_node_get_name(node), "variablelist")) {
		return ret;
	}

	/* use this spacing (add 4 spaces) inside a variablelist node. */
	ast_asprintf(&vartabs, "%s    ", tabs);
	if (!vartabs) {
		return ret;
	}
	for (tmp = ast_xml_node_get_children(node); tmp; tmp = ast_xml_node_get_next(tmp)) {
		/* We can have a <para> element inside the variable list */
		if ((xmldoc_parse_para(tmp, (ret ? tabs : ""), "\n", buffer))) {
			ret = 1;
			continue;
		} else if ((xmldoc_parse_specialtags(tmp, (ret ? tabs : ""), "\n", buffer))) {
			ret = 1;
			continue;
		}

		if (!strcasecmp(ast_xml_node_get_name(tmp), "variable")) {
			/* Store the variable name in buffer. */
			varname = ast_xml_get_attribute(tmp, "name");
			if (varname) {
				ast_str_append(buffer, 0, "%s<variable>%s</variable>: ", tabs, varname);
				ast_xml_free_attr(varname);
				/* Parse the <variable> possible values. */
				xmldoc_parse_variable(tmp, vartabs, buffer);
				ret = 1;
			}
		}
	}

	ast_free(vartabs);

	return ret;
}

char *ast_xmldoc_build_seealso(const char *type, const char *name)
{
	struct ast_str *outputstr;
	char *output;
	struct ast_xml_node *node;
	const char *typename;
	const char *content;
	int first = 1;

	if (ast_strlen_zero(type) || ast_strlen_zero(name)) {
		return NULL;
	}

	/* get the application/function root node. */
	node = xmldoc_get_node(type, name, documentation_language);
	if (!node || !ast_xml_node_get_children(node)) {
		return NULL;
	}

	/* Find the <see-also> node. */
	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (!strcasecmp(ast_xml_node_get_name(node), "see-also")) {
			break;
		}
	}

	if (!node || !ast_xml_node_get_children(node)) {
		/* we couldnt find a <see-also> node. */
		return NULL;
	}

	/* prepare the output string. */
	outputstr = ast_str_create(128);
	if (!outputstr) {
		return NULL;
	}

	/* get into the <see-also> node. */
	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (strcasecmp(ast_xml_node_get_name(node), "ref")) {
			continue;
		}

		/* parse the <ref> node. 'type' attribute is required. */
		typename = ast_xml_get_attribute(node, "type");
		if (!typename) {
			continue;
		}
		content = ast_xml_get_text(node);
		if (!content) {
			ast_xml_free_attr(typename);
			continue;
		}
		if (!strcasecmp(typename, "application")) {
			ast_str_append(&outputstr, 0, "%s%s()",	(first ? "" : ", "), content);
		} else if (!strcasecmp(typename, "function")) {
			ast_str_append(&outputstr, 0, "%s%s", (first ? "" : ", "), content);
		} else if (!strcasecmp(typename, "astcli")) {
			ast_str_append(&outputstr, 0, "%s<astcli>%s</astcli>", (first ? "" : ", "), content);
		} else {
			ast_str_append(&outputstr, 0, "%s%s", (first ? "" : ", "), content);
		}
		first = 0;
		ast_xml_free_text(content);
		ast_xml_free_attr(typename);
	}

	output = ast_strdup(ast_str_buffer(outputstr));
	ast_free(outputstr);

	return output;
}

/*! \internal
 *  \brief Parse a <enum> node.
 *  \brief fixnode An ast_xml_node pointer to the <enum> node.
 *  \bried buffer The output buffer.
 *  \retval 0 if content is not found inside the enum element (data is not appended to buffer).
 *  \retval 1 if content is found and data is appended to buffer.
 */
static int xmldoc_parse_enum(struct ast_xml_node *fixnode, const char *tabs, struct ast_str **buffer)
{
	struct ast_xml_node *node = fixnode;
	int ret = 0;
	char *optiontabs;

	ast_asprintf(&optiontabs, "%s    ", tabs);

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if ((xmldoc_parse_para(node, (ret ? tabs : " - "), "\n", buffer))) {
			ret = 1;
		} else if ((xmldoc_parse_specialtags(node, (ret ? tabs : " - "), "\n", buffer))) {
			ret = 1;
		}

		xmldoc_parse_enumlist(node, optiontabs, buffer);
	}

	ast_free(optiontabs);

	return ret;
}

/*! \internal
 *  \brief Parse a <enumlist> node.
 *  \param fixnode As ast_xml pointer to the <enumlist> node.
 *  \param buffer The ast_str output buffer.
 *  \retval 0 if no <enumlist> node was parsed.
 *  \retval 1 if a <enumlist> node was parsed.
 */
static int xmldoc_parse_enumlist(struct ast_xml_node *fixnode, const char *tabs, struct ast_str **buffer)
{
	struct ast_xml_node *node = fixnode;
	const char *enumname;
	int ret = 0;

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (strcasecmp(ast_xml_node_get_name(node), "enum")) {
			continue;
		}

		enumname = ast_xml_get_attribute(node, "name");
		if (enumname) {
			ast_str_append(buffer, 0, "%s<enum>%s</enum>", tabs, enumname);
			ast_xml_free_attr(enumname);

			/* parse only enum elements inside a enumlist node. */
			if ((xmldoc_parse_enum(node, tabs, buffer))) {
				ret = 1;
			} else {
				ast_str_append(buffer, 0, "\n");
			}
		}
	}
	return ret;
}

/*! \internal
 *  \brief Parse an <option> node.
 *  \param fixnode An ast_xml pointer to the <option> node.
 *  \param tabs A string to be appended at the begining of each line being added to the
 *              buffer string.
 *  \param buffer The output buffer.
 *  \retval 0 if no option node is parsed.
 *  \retval 1 if an option node is parsed.
 */
static int xmldoc_parse_option(struct ast_xml_node *fixnode, const char *tabs, struct ast_str **buffer)
{
	struct ast_xml_node *node;
	int ret = 0;
	char *optiontabs;

	ast_asprintf(&optiontabs, "%s    ", tabs);
	if (!optiontabs) {
		return ret;
	}
	for (node = ast_xml_node_get_children(fixnode); node; node = ast_xml_node_get_next(node)) {
		if (!strcasecmp(ast_xml_node_get_name(node), "argument")) {
			/* if this is the first data appended to buffer, print a \n*/
			if (!ret && ast_xml_node_get_children(node)) {
				/* print \n */
				ast_str_append(buffer, 0, "\n");
			}
			if (xmldoc_parse_argument(node, 0, NULL, optiontabs, buffer)) {
				ret = 1;
			}
			continue;
		}

		if (xmldoc_parse_para(node, (ret ? tabs :  ""), "\n", buffer)) {
			ret = 1;
		} else if (xmldoc_parse_specialtags(node, (ret ? tabs :  ""), "\n", buffer)) {
			ret = 1;
		}

		xmldoc_parse_variablelist(node, optiontabs, buffer);

		xmldoc_parse_enumlist(node, optiontabs, buffer);
	}
	ast_free(optiontabs);

	return ret;
}

/*! \internal
 *  \brief Parse an <optionlist> element from the xml documentation.
 *  \param fixnode Pointer to the optionlist xml node.
 *  \param tabs A string to be appended at the begining of each line being added to the
 *              buffer string.
 *  \param buffer Output buffer to put what is inside the optionlist tag.
 */
static void xmldoc_parse_optionlist(struct ast_xml_node *fixnode, const char *tabs, struct ast_str **buffer)
{
	struct ast_xml_node *node;
	const char *optname, *hasparams;
	char *optionsyntax;
	int optparams;

	for (node = ast_xml_node_get_children(fixnode); node; node = ast_xml_node_get_next(node)) {
		/* Start appending every option tag. */
		if (strcasecmp(ast_xml_node_get_name(node), "option")) {
			continue;
		}

		/* Get the option name. */
		optname = ast_xml_get_attribute(node, "name");
		if (!optname) {
			continue;
		}

		optparams = 1;
		hasparams = ast_xml_get_attribute(node, "hasparams");
		if (hasparams && !strcasecmp(hasparams, "optional")) {
			optparams = 2;
		}

		optionsyntax = xmldoc_get_syntax_fun(node, optname, "argument", 0, optparams);
		if (!optionsyntax) {
			ast_xml_free_attr(optname);
			ast_xml_free_attr(hasparams);
			continue;
		}

		ast_str_append(buffer, 0, "%s%s: ", tabs, optionsyntax);

		if (!xmldoc_parse_option(node, tabs, buffer)) {
			ast_str_append(buffer, 0, "\n");
		}
		ast_str_append(buffer, 0, "\n");
		ast_xml_free_attr(optname);
		ast_xml_free_attr(hasparams);
	}
}

/*! \internal
 *  \brief Parse a 'parameter' tag inside a syntax element.
 *  \param fixnode A pointer to the 'parameter' xml node.
 *  \param tabs A string to be appended at the beginning of each line being printed inside
 *              'buffer'.
 *  \param buffer String buffer to put values found inside the parameter element.
 */
static void xmldoc_parse_parameter(struct ast_xml_node *fixnode, const char *tabs, struct ast_str **buffer)
{
	const char *paramname;
	struct ast_xml_node *node = fixnode;
	int hasarguments, printed = 0;
	char *internaltabs;

	if (strcasecmp(ast_xml_node_get_name(node), "parameter")) {
		return;
	}

	hasarguments = xmldoc_has_inside(node, "argument");
	if (!(paramname = ast_xml_get_attribute(node, "name"))) {
		/* parameter MUST have an attribute name. */
		return;
	}

	ast_asprintf(&internaltabs, "%s    ", tabs);
	if (!internaltabs) {
		return;
	}

	if (!hasarguments && xmldoc_has_nodes(node)) {
		ast_str_append(buffer, 0, "%s\n", paramname);
		ast_xml_free_attr(paramname);
		printed = 1;
	}

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (!strcasecmp(ast_xml_node_get_name(node), "optionlist")) {
			xmldoc_parse_optionlist(node, internaltabs, buffer);
		} else if (!strcasecmp(ast_xml_node_get_name(node), "enumlist")) {
			xmldoc_parse_enumlist(node, internaltabs, buffer);
		} else if (!strcasecmp(ast_xml_node_get_name(node), "argument")) {
			xmldoc_parse_argument(node, 1, internaltabs, (!hasarguments ? "        " : ""), buffer);
		} else if (!strcasecmp(ast_xml_node_get_name(node), "para")) {
			if (!printed) {
				ast_str_append(buffer, 0, "%s\n", paramname);
				ast_xml_free_attr(paramname);
				printed = 1;
			}
			xmldoc_parse_para(node, internaltabs, "\n", buffer);
			continue;
		} else if ((xmldoc_parse_specialtags(node, internaltabs, "\n", buffer))) {
			continue;
		}
	}
	if (!printed) {
		ast_xml_free_attr(paramname);
	}
	ast_free(internaltabs);
}

char *ast_xmldoc_build_arguments(const char *type, const char *name)
{
	struct ast_xml_node *node;
	struct ast_str *ret = ast_str_create(128);
	char *retstr = NULL;

	if (ast_strlen_zero(type) || ast_strlen_zero(name)) {
		return NULL;
	}

	node = xmldoc_get_node(type, name, documentation_language);

	if (!node || !ast_xml_node_get_children(node)) {
		return NULL;
	}

	/* Find the syntax field. */
	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		if (!strcasecmp(ast_xml_node_get_name(node), "syntax")) {
			break;
		}
	}

	if (!node || !ast_xml_node_get_children(node)) {
		/* We couldn't find the syntax node. */
		return NULL;
	}

	for (node = ast_xml_node_get_children(node); node; node = ast_xml_node_get_next(node)) {
		xmldoc_parse_parameter(node, "", &ret);
	}

	if (ast_str_strlen(ret) > 0) {
		/* remove last '\n' */
		char *buf = ast_str_buffer(ret);
		if (buf[ast_str_strlen(ret) - 1] == '\n') {
			ast_str_truncate(ret, -1);
		}
		retstr = ast_strdup(ast_str_buffer(ret));
	}
	ast_free(ret);

	return retstr;
}

/*! \internal
 *  \brief Return the string within a node formatted with <para> and <variablelist> elements.
 *  \param node Parent node where content resides.
 *  \param raw If set, return the node's content without further processing.
 *  \param raw_wrap Wrap raw text.
 *  \retval NULL on error
 *  \retval Node content on success.
 */
static struct ast_str *xmldoc_get_formatted(struct ast_xml_node *node, int raw_output, int raw_wrap)
{
	struct ast_xml_node *tmp;
	const char *notcleanret, *tmpstr;
	struct ast_str *ret = ast_str_create(128);

	if (raw_output) {
		notcleanret = ast_xml_get_text(node);
		tmpstr = notcleanret;
		xmldoc_string_cleanup(ast_skip_blanks(notcleanret), &ret, 0);
		ast_xml_free_text(tmpstr);
	} else {
		for (tmp = ast_xml_node_get_children(node); tmp; tmp = ast_xml_node_get_next(tmp)) {
			/* if found, parse a <para> element. */
			if (xmldoc_parse_para(tmp, "", "\n", &ret)) {
				continue;
			} else if (xmldoc_parse_specialtags(tmp, "", "\n", &ret)) {
				continue;
			}
			/* if found, parse a <variablelist> element. */
			xmldoc_parse_variablelist(tmp, "", &ret);
			xmldoc_parse_enumlist(tmp, "    ", &ret);
		}
		/* remove last '\n' */
		/* XXX Don't modify ast_str internals manually */
		tmpstr = ast_str_buffer(ret);
		if (tmpstr[ast_str_strlen(ret) - 1] == '\n') {
			ast_str_truncate(ret, -1);
		}
	}
	return ret;
}

/*!
 *  \brief Get the content of a field (synopsis, description, etc) from an asterisk document tree
 *  \param type Type of element (application, function, ...).
 *  \param name Name of element (Dial, Echo, Playback, ...).
 *  \param var Name of field to return (synopsis, description, etc).
 *  \param raw Field only contains text, no other elements inside it.
 *  \retval NULL On error.
 *  \retval Field text content on success.
 */
static char *xmldoc_build_field(const char *type, const char *name, const char *var, int raw)
{
	struct ast_xml_node *node;
	char *ret = NULL;
	struct ast_str *formatted;

	if (ast_strlen_zero(type) || ast_strlen_zero(name)) {
		ast_log(LOG_ERROR, "Tried to look in XML tree with faulty values.\n");
		return ret;
	}

	node = xmldoc_get_node(type, name, documentation_language);

	if (!node) {
		ast_log(LOG_WARNING, "Couldn't find %s %s in XML documentation\n", type, name);
		return ret;
	}

	node = ast_xml_find_element(ast_xml_node_get_children(node), var, NULL, NULL);

	if (!node || !ast_xml_node_get_children(node)) {
		ast_log(LOG_DEBUG, "Cannot find variable '%s' in tree '%s'\n", name, var);
		return ret;
	}

	formatted = xmldoc_get_formatted(node, raw, raw);
	if (ast_str_strlen(formatted) > 0) {
		ret = ast_strdup(ast_str_buffer(formatted));
	}
	ast_free(formatted);

	return ret;
}

char *ast_xmldoc_build_synopsis(const char *type, const char *name)
{
	return xmldoc_build_field(type, name, "synopsis", 1);
}

char *ast_xmldoc_build_description(const char *type, const char *name)
{
	return xmldoc_build_field(type, name, "description", 0);
}

#if !defined(HAVE_GLOB_NOMAGIC) || !defined(HAVE_GLOB_BRACE) || defined(DEBUG_NONGNU)
static int xml_pathmatch(char *xmlpattern, int xmlpattern_maxlen, glob_t *globbuf)
{
	int globret;

	snprintf(xmlpattern, xmlpattern_maxlen, "%s/documentation/thirdparty/*-%s.xml",
		ast_config_AST_DATA_DIR, documentation_language);
	if((globret = glob(xmlpattern, GLOB_NOCHECK, NULL, globbuf))) {
		return globret;
	}

	snprintf(xmlpattern, xmlpattern_maxlen, "%s/documentation/thirdparty/*-%.2s_??.xml",
		ast_config_AST_DATA_DIR, documentation_language);
	if((globret = glob(xmlpattern, GLOB_APPEND | GLOB_NOCHECK, NULL, globbuf))) {
		return globret;
	}

	snprintf(xmlpattern, xmlpattern_maxlen, "%s/documentation/thirdparty/*-%s.xml",
		ast_config_AST_DATA_DIR, default_documentation_language);
	if((globret = glob(xmlpattern, GLOB_APPEND | GLOB_NOCHECK, NULL, globbuf))) {
		return globret;
	}

	snprintf(xmlpattern, xmlpattern_maxlen, "%s/documentation/*-%s.xml",
		ast_config_AST_DATA_DIR, documentation_language);
	if((globret = glob(xmlpattern, GLOB_APPEND | GLOB_NOCHECK, NULL, globbuf))) {
		return globret;
	}

	snprintf(xmlpattern, xmlpattern_maxlen, "%s/documentation/*-%.2s_??.xml",
		ast_config_AST_DATA_DIR, documentation_language);
	if((globret = glob(xmlpattern, GLOB_APPEND | GLOB_NOCHECK, NULL, globbuf))) {
		return globret;
	}

	snprintf(xmlpattern, xmlpattern_maxlen, "%s/documentation/*-%s.xml",
		ast_config_AST_DATA_DIR, default_documentation_language);
	globret = glob(xmlpattern, GLOB_APPEND | GLOB_NOCHECK, NULL, globbuf);

	return globret;
}
#endif

/*! \brief Close and unload XML documentation. */
static void xmldoc_unload_documentation(void)
{
        struct documentation_tree *doctree;

	AST_RWLIST_WRLOCK(&xmldoc_tree);
	while ((doctree = AST_RWLIST_REMOVE_HEAD(&xmldoc_tree, entry))) {
		ast_free(doctree->filename);
		ast_xml_close(doctree->doc);
	}
	AST_RWLIST_UNLOCK(&xmldoc_tree);

	ast_xml_finish();
}

int ast_xmldoc_load_documentation(void)
{
	struct ast_xml_node *root_node;
	struct ast_xml_doc *tmpdoc;
	struct documentation_tree *doc_tree;
	char *xmlpattern;
	struct ast_config *cfg = NULL;
	struct ast_variable *var = NULL;
	struct ast_flags cnfflags = { 0 };
	int globret, i, dup, duplicate;
	glob_t globbuf;
#if !defined(HAVE_GLOB_NOMAGIC) || !defined(HAVE_GLOB_BRACE) || defined(DEBUG_NONGNU)
	int xmlpattern_maxlen;
#endif

	/* setup default XML documentation language */
	snprintf(documentation_language, sizeof(documentation_language), default_documentation_language);

	if ((cfg = ast_config_load2("asterisk.conf", "" /* core can't reload */, cnfflags)) && cfg != CONFIG_STATUS_FILEINVALID) {
		for (var = ast_variable_browse(cfg, "options"); var; var = var->next) {
			if (!strcasecmp(var->name, "documentation_language")) {
				if (!ast_strlen_zero(var->value)) {
					snprintf(documentation_language, sizeof(documentation_language), "%s", var->value);
				}
			}
		}
		ast_config_destroy(cfg);
	}

	/* initialize the XML library. */
	ast_xml_init();

	/* register function to be run when asterisk finish. */
	ast_register_atexit(xmldoc_unload_documentation);

	globbuf.gl_offs = 0;    /* slots to reserve in gl_pathv */

#if !defined(HAVE_GLOB_NOMAGIC) || !defined(HAVE_GLOB_BRACE) || defined(DEBUG_NONGNU)
	xmlpattern_maxlen = strlen(ast_config_AST_DATA_DIR) + strlen("/documentation/thirdparty") + strlen("/*-??_??.xml") + 1;
	xmlpattern = ast_malloc(xmlpattern_maxlen);
	globret = xml_pathmatch(xmlpattern, xmlpattern_maxlen, &globbuf);
#else
	/* Get every *-LANG.xml file inside $(ASTDATADIR)/documentation */
	ast_asprintf(&xmlpattern, "%s/documentation{/thirdparty/,/}*-{%s,%.2s_??,%s}.xml", ast_config_AST_DATA_DIR,
		documentation_language, documentation_language, default_documentation_language);
	globret = glob(xmlpattern, MY_GLOB_FLAGS, NULL, &globbuf);
#endif

	ast_debug(3, "gl_pathc %zd\n", globbuf.gl_pathc);
	if (globret == GLOB_NOSPACE) {
		ast_log(LOG_WARNING, "XML load failure, glob expansion of pattern '%s' failed: Not enough memory\n", xmlpattern);
		ast_free(xmlpattern);
		return 1;
	} else if (globret  == GLOB_ABORTED) {
		ast_log(LOG_WARNING, "XML load failure, glob expansion of pattern '%s' failed: Read error\n", xmlpattern);
		ast_free(xmlpattern);
		return 1;
	}
	ast_free(xmlpattern);

	AST_RWLIST_WRLOCK(&xmldoc_tree);
	/* loop over expanded files */
	for (i = 0; i < globbuf.gl_pathc; i++) {
		/* check for duplicates (if we already [try to] open the same file. */
		duplicate = 0;
		for (dup = 0; dup < i; dup++) {
			if (!strcmp(globbuf.gl_pathv[i], globbuf.gl_pathv[dup])) {
				duplicate = 1;
				break;
			}
		}
		if (duplicate || strchr(globbuf.gl_pathv[i], '*')) {
		/* skip duplicates as well as pathnames not found 
		 * (due to use of GLOB_NOCHECK in xml_pathmatch) */
			continue;
		}
		tmpdoc = NULL;
		tmpdoc = ast_xml_open(globbuf.gl_pathv[i]);
		if (!tmpdoc) {
			ast_log(LOG_ERROR, "Could not open XML documentation at '%s'\n", globbuf.gl_pathv[i]);
			continue;
		}
		/* Get doc root node and check if it starts with '<docs>' */
		root_node = ast_xml_get_root(tmpdoc);
		if (!root_node) {
			ast_log(LOG_ERROR, "Error getting documentation root node");
			ast_xml_close(tmpdoc);
			continue;
		}
		/* Check root node name for malformed xmls. */
		if (strcmp(ast_xml_node_get_name(root_node), "docs")) {
			ast_log(LOG_ERROR, "Documentation file is not well formed!\n");
			ast_xml_close(tmpdoc);
			continue;
		}
		doc_tree = ast_calloc(1, sizeof(*doc_tree));
		if (!doc_tree) {
			ast_log(LOG_ERROR, "Unable to allocate documentation_tree structure!\n");
			ast_xml_close(tmpdoc);
			continue;
		}
		doc_tree->doc = tmpdoc;
		doc_tree->filename = ast_strdup(globbuf.gl_pathv[i]);
		AST_RWLIST_INSERT_TAIL(&xmldoc_tree, doc_tree, entry);
	}
	AST_RWLIST_UNLOCK(&xmldoc_tree);

	globfree(&globbuf);

	return 0;
}

#endif /* AST_XML_DOCS */