/*
* xmlTreeEnsureXMLDecl:
* @doc: the doc
*
* Ensures that there is an XML namespace declaration on the doc.
*
* Returns the XML ns-struct or NULL on API and internal errors.
*/
static xmlNsPtr
xmlTreeEnsureXMLDecl(xmlDocPtr doc)
{
    if (doc == NULL)
	return (NULL);
    if (doc->oldNs != NULL)
	return (doc->oldNs);
    {
	xmlNsPtr ns;
	ns = (xmlNsPtr) xmlMalloc(sizeof(xmlNs));
	if (ns == NULL) {
	    xmlTreeErrMemory(
		"allocating the XML namespace");
	    return (NULL);
	}
	memset(ns, 0, sizeof(xmlNs));
	ns->type = XML_LOCAL_NAMESPACE;
	ns->href = xmlStrdup(XML_XML_NAMESPACE);
	ns->prefix = xmlStrdup((const xmlChar *)"xml");
	doc->oldNs = ns;
	return (ns);
    }
}

/*
* xmlTreeAquireDocOldNs:
* @doc: the doc
* @nsName: the namespace name
* @prefix: the prefix
*
* Creates or reuses an xmlNs struct on doc->oldNs with
* the given prefix and namespace name.
*
* Returns the aquired ns struct or NULL in case of an API
*         or internal error.
*/
static xmlNsPtr
xmlTreeAquireDocOldNs(xmlDocPtr doc,
		   const xmlChar *nsName,
		   const xmlChar *prefix)
{
    xmlNsPtr ns;

    if (doc == NULL)
	return (NULL);
    ns = xmlTreeEnsureXMLDecl(doc);
    if (ns == NULL)
	return (NULL);
    if (ns->next != NULL) {
	/* Reuse. */
	ns = ns->next;
	while (ns != NULL) {
	    if (((ns->prefix == prefix) ||
		xmlStrEqual(ns->prefix, prefix)) &&
		xmlStrEqual(ns->href, nsName)) {
		return (ns);
	    }
	    if (ns->next == NULL)
		break;
	    ns = ns->next;
	}
    }
    /* Create. */
    ns->next = xmlNewNs(NULL, NULL, NULL);
    if (ns->next == NULL)
	return (NULL);
    ns = ns->next;
    if (doc->dict) {
	if (prefix != NULL)
	    ns->prefix = xmlDictLookup(doc->dict, prefix, -1);
	ns->href = xmlDictLookup(doc->dict, nsName, -1);
    } else {
	if (prefix != NULL)
	    ns->prefix = BAD_CAST xmlStrdup(prefix);
	ns->href = BAD_CAST xmlStrdup(nsName);
    }
}

static int
xmlDOMWrapAddNsMapItem2(xmlNsPtr **list, int *size, int *number,
			xmlNsPtr oldNs, xmlNsPtr newNs)
{
    if (*list == NULL) {
	*list = (xmlNsPtr *) xmlMalloc(6 * sizeof(xmlNsPtr));
	if (*list == NULL) {
	    xmlTreeErrMemory("alloc ns map item");
	    return(-1);
	}
	*size = 3;
	*number = 0;
    } else if ((*number) >= (*size)) {
	*size *= 2;
	*list = (xmlNsPtr *) xmlRealloc(*list,
	    (*size) * 2 * sizeof(xmlNsPtr));
	if (*list == NULL) {
	    xmlTreeErrMemory("realloc ns map item");
	    return(-1);
	}
    }
    (*list)[2 * (*number)] = oldNs;
    (*list)[2 * (*number) +1] = newNs;
    (*number)++;
}

/*
* xmlDOMWrapRemoveNode:
*
* @doc: the doc
* @node: the node to be removed.
*
* Unlinks the given node from its owner.
* This will substitute ns-references to node->nsDef for
* ns-references to doc->oldNs, thus ensuring the removed
* branch to be autonomous of any other node in the doc
* wrt to ns-references.
*
* Returns 0 on success, 1 if the node is not supported,
*         -1 on API and internal errors.
*/
static int
xmlDOMWrapRemoveNode(xmlDocPtr doc, xmlNodePtr node)
{
    xmlNsPtr *list = NULL;
    int sizeList, nbList, i, j;
    xmlNsPtr ns;

    if ((node == NULL) || (doc == NULL))
	return (-1);

    /* TODO: 0 or -1 ? */
    if (node->parent == NULL)
	return (0);

    switch (node->type) {
	case XML_TEXT_NODE:
	case XML_CDATA_SECTION_NODE:
	case XML_ENTITY_REF_NODE:
	case XML_PI_NODE:
	case XML_COMMENT_NODE:
	    xmlUnlinkNode(node);
	    return (0);
	case XML_ELEMENT_NODE:
	case XML_ATTRIBUTE_NODE:
	    break;
	default:
	    return (1);
    }
    xmlUnlinkNode(node);
    /*
    * Save out-of-scope ns-references in doc->oldNs.
    */
    do {
	switch (node->type) {
	    case XML_ELEMENT_NODE:
		if (node->nsDef != NULL) {
		    ns = node->nsDef;
		    do {
			if (xmlDOMWrapAddNsMapItem2(&list, &sizeList,
			    &nbList, ns, ns) == -1)
			    goto internal_error;
		    } while (ns != NULL);
		}
		/* No break on purpose. */
	    case XML_ATTRIBUTE_NODE:
		if (node->ns != NULL) {
		    /*
		    * Find a mapping.
		    */
		    if (list != NULL) {
			for (i = 0, j = 0; i < nbList; i++, j += 2) {
			    if (node->ns == list[j]) {
				node->ns = list[++j];
				goto next_node;
			    }
			}
		    }
		    /*
		    * Search in doc's oldNs.
		    */
		    if (doc->oldNs != NULL) {
			ns = doc->oldNs;
			do {
			    if (node->ns == ns)
				goto next_node;
			    ns = ns->next;
			} while (ns != NULL);
		    }
		    /*
		    * Add to doc's oldNs.
		    */
		    ns = xmlTreeAquireDocOldNs(doc, node->ns->href,
			node->ns->prefix);
		    if (ns == NULL)
			goto internal_error;
		    /*
		    * Add mapping.
		    */
		    if (xmlDOMWrapAddNsMapItem2(&list, &sizeList,
			&nbList, node->ns, ns) == -1)
			goto internal_error;
		    node->ns = ns;
		}
		break;
	    default:
		goto next_sibling;
	}

next_node:
	if ((node->type == XML_ELEMENT_NODE) &&
	    (node->children != NULL)) {
	    node = node->children;
	    continue;
	}
next_sibling:
	if (node == NULL)
	    break;
	if (node->next != NULL)
	    node = node->next;
	else {
	    node = node->parent;
	    goto next_sibling;
	}
    } while (node != NULL);

    if (list != NULL)
	xmlFree(list);
    return (0);

internal_error:
    if (list != NULL)
	xmlFree(list);
    return (-1);
}