/*

 * Copyright 2004-2026 the Pacemaker project contributors

 *

 * The version control history for this file may have further details.

 *

 * This source code is licensed under the GNU Lesser General Public License

 * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.

 */

#include <crm_internal.h>

#include <stdio.h>              // NULL

#include <stdlib.h>             // free()

#include <glib.h>               // GList, GHashTable, etc.

#include <libxml/tree.h>        // xmlNode

#include <crm/crm.h>

#include <crm/common/xml.h>     // PCMK_XA_ID_REF

/*!

 * \internal

 * \brief Add an XML ID reference to a table

 *

 * \param[in,out] table      Table of ID references to add to

 * \param[in]     id         ID of primary element being referred to

 * \param[in]     referrer   ID of element referring to \p id

 *

 * \note This refers to an ID reference in general, not necessarily connected to

 *       an id-ref attribute.

 */

void

pcmk__add_idref(GHashTable *table, const char *id, const char *referrer)

{

    pcmk__idref_t *idref = NULL;

    pcmk__assert((table != NULL) && (id != NULL) && (referrer != NULL));

    idref = g_hash_table_lookup(table, id);

    if (idref == NULL) {

        idref = pcmk__assert_alloc(1, sizeof(pcmk__idref_t));

        idref->id = pcmk__str_copy(id);

        g_hash_table_insert(table, pcmk__str_copy(id), idref);

    }

    for (GList *iter = idref->refs; iter != NULL; iter = iter->next) {

        if (pcmk__str_eq(referrer, (const char *) iter->data,

                         pcmk__str_none)) {

            return; // Already present

        }

    }

    idref->refs = g_list_append(idref->refs, pcmk__str_copy(referrer));

    pcmk__trace("Added ID %s referrer %s", id, referrer);

}

/*!

 * \internal

 * \brief Free a pcmk__idref_t

 *

 * \param[in,out] data  pcmk__idref_t to free

 */

void

pcmk__free_idref(void *data)

{

    pcmk__idref_t *idref = data;

    if (idref != NULL) {

        free(idref->id);

        g_list_free_full(idref->refs, free);

        free(idref);

    }

}

/*!

 * \internal

 * \brief Get the XML element whose \c PCMK_XA_ID matches an \c PCMK_XA_ID_REF

 *

 * \param[in] xml  Element whose \c PCMK_XA_ID_REF attribute to check

 * \param[in] doc  Document to search for node with matching \c PCMK_XA_ID

 *

 * \return If \p xml has a \c PCMK_XA_ID_REF attribute, node in \p doc whose

 *         \c PCMK_XA_ID attribute matches; otherwise, \p xml

 */

xmlNode *

pcmk__xe_resolve_idref(xmlNode *xml, xmlDoc *doc)

{

    char *xpath = NULL;

    const char *ref = NULL;

    xmlNode *result = NULL;

    if ((xml == NULL) || (doc == NULL)) {

        return NULL;

    }

    ref = pcmk__xe_get(xml, PCMK_XA_ID_REF);

    if (ref == NULL) {

        return xml;

    }

    xpath = pcmk__assert_asprintf("//%s[@" PCMK_XA_ID "='%s']", xml->name, ref);

    result = pcmk__xpath_find_one(doc, xpath, LOG_DEBUG);

    if (result == NULL) {

        // Not possible with schema validation enabled

        pcmk__config_err("Ignoring invalid %s configuration: "

                         PCMK_XA_ID_REF " '%s' does not reference "

                         "a valid object " QB_XS " xpath=%s",

                         xml->name, ref, xpath);

    }

    free(xpath);

    return result;

}

/*!

 * \internal

 * \brief Get list of resolved ID references for child elements of given element

 *

 * \param[in] xml           XML element to get list for

 * \param[in] element_name  If not NULL, list only children of this element type

 * \param[in] doc           XML document to use for resolving references

 *

 * \return Unordered list of XML elements corresponding to child elements of

 *         \p xml with any ID references resolved to the referenced elements

 */

GList *

pcmk__xe_dereference_children(const xmlNode *xml, const char *element_name,

                              xmlDoc *doc)

{

    GList *result = NULL;

    if (xml == NULL) {

        return NULL;

    }

    for (xmlNode *child = pcmk__xe_first_child(xml, element_name, NULL, NULL);

         child != NULL; child = pcmk__xe_next(child, element_name)) {

        xmlNode *resolved = pcmk__xe_resolve_idref(child, doc);

        if (resolved == NULL) {

            continue; // Not possible with schema validation enabled

        }

        result = g_list_prepend(result, resolved);

    }

    return result;

}