/*
 * Copyright (C) 2013  Patrick "P. J." McDermott
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 */

#include <string.h>
#include <stdio.h>
#include <inttypes.h>
#include <expat.h>
#include <SDL_stdinc.h>
#include "xml.h"
#include "logging.h"

struct xml_node {
	void *data;
	XML_StartElementHandler start;
	XML_EndElementHandler end;
	XML_CharacterDataHandler charhndl;
	struct xml_node *parent;
};

int
xml_check_tag(const char *found, const char *expected)
{
	return strcmp(found, expected) == 0;
}

void
xml_unexpected_start_tag(XML_Parser p, const char *found, const char *expected)
{
	warn("Found \"%s\" start tag where expected one of \"%s\" in map",
			found, expected);
	XML_StopParser(p, XML_FALSE);
}

void
xml_unexpected_end_tag(XML_Parser p, const char *found, const char *expected)
{
	warn("Found \"%s\" end tag where expected one of \"%s\" in map",
			found, expected);
	XML_StopParser(p, XML_FALSE);
}

void
xml_get_uint32_attr(XML_Parser p, const char **attr, const char *name,
		Uint32 *dest, int req)
{
	for (; attr[0] != NULL; attr += 2) {
		if (strcmp(attr[0], name) == 0) {
			if (sscanf(attr[1], "%" PRIu32, dest) == 1) {
				return;
			} else if (req) {
				warn("Invalid \"%s\" attribute value", name);
				XML_StopParser(p, XML_FALSE);
			}
		}
	}
	if (req) {
		warn("Required attribute \"%s\" not found", name);
		XML_StopParser(p, XML_FALSE);
	}
}

void
xml_get_int_attr(XML_Parser p, const char **attr, const char *name,
		int *dest, int req)
{
	for (; attr[0] != NULL; attr += 2) {
		if (strcmp(attr[0], name) == 0) {
			if (sscanf(attr[1], "%d", dest) == 1) {
				return;
			} else if (req) {
				warn("Invalid \"%s\" attribute value", name);
				XML_StopParser(p, XML_FALSE);
			}
		}
	}
	if (req) {
		warn("Required attribute \"%s\" not found", name);
		XML_StopParser(p, XML_FALSE);
	}
}

void
xml_get_string_attr(XML_Parser p, const char **attr, const char *name,
		char **dest, int req)
{
	for (; attr[0] != NULL; attr += 2) {
		if (strcmp(attr[0], name) == 0) {
			*dest = strdup(attr[1]);
			return;
		}
	}
	if (req) {
		warn("Required attribute \"%s\" not found", name);
		XML_StopParser(p, XML_FALSE);
	}
}

void
xml_node_push(XML_Parser p, void *data,
		XML_StartElementHandler start, XML_EndElementHandler end,
		XML_CharacterDataHandler charhndl)
{
	struct xml_node *n;

	n = malloc(sizeof(*n));
	if (n == NULL) {
		return;
	}
	n->data = data;
	n->start = start;
	n->end = end;
	n->charhndl = charhndl;
	n->parent = (struct xml_node *) XML_GetUserData(p);
	XML_SetUserData(p, n);
	XML_SetStartElementHandler(p, n->start);
	XML_SetEndElementHandler(p, n->end);
	XML_SetCharacterDataHandler(p, n->charhndl);
}

void *
xml_node_pop(XML_Parser p)
{
	struct xml_node *n;
	void *data;

	n = (struct xml_node *) XML_GetUserData(p);
	data = n->data;
	XML_SetUserData(p, n->parent);
	free(n);

	n = (struct xml_node *) XML_GetUserData(p);
	if (n == NULL) {
		XML_SetStartElementHandler(p, NULL);
		XML_SetEndElementHandler(p, NULL);
		XML_SetCharacterDataHandler(p, NULL);
	} else {
		XML_SetStartElementHandler(p, n->start);
		XML_SetEndElementHandler(p, n->end);
		XML_SetCharacterDataHandler(p, n->charhndl);
	}

	return data;
}

void *
xml_node_peek(XML_Parser p)
{
	struct xml_node *n;

	n = (struct xml_node *) XML_GetUserData(p);

	return n->data;
}