/*
	 * Copyright 2004-2023 the Pacemaker project contributors
	 *
	 * The version control history for this file may have further details.
	 *
	 * This source code is licensed under the GNU General Public License version 2
	 * or later (GPLv2+) WITHOUT ANY WARRANTY.
	 */
	
	#include <crm_internal.h>
	
	#include <unistd.h>  /* pid_t, sleep, ssize_t */
	
	#include <crm/cib.h>
	#include <crm/cluster.h>
	#include <crm/common/xml.h>
	#include <crm/crm.h>
	#include <crm/msg_xml.h>
	#include <crm/common/xml_internal.h>
	#include <crm/common/ipc.h>
	#include <crm/common/ipc_schedulerd.h>
	
	#include <pacemaker-controld.h>
	
	static void handle_disconnect(void);
	
	static pcmk_ipc_api_t *schedulerd_api = NULL;
	
	/*!
	 * \internal
	 * \brief Close any scheduler connection and free associated memory
	 */
	void
	controld_shutdown_schedulerd_ipc(void)
	{
	    controld_clear_fsa_input_flags(R_PE_REQUIRED);
	    pcmk_disconnect_ipc(schedulerd_api);
	    handle_disconnect();
	
	    pcmk_free_ipc_api(schedulerd_api);
	    schedulerd_api = NULL;
	}
	
	/*!
	 * \internal
	 * \brief Save CIB query result to file, raising FSA error
	 *
	 * \param[in] msg        Ignored
	 * \param[in] call_id    Call ID of CIB query
	 * \param[in] rc         Return code of CIB query
	 * \param[in] output     Result of CIB query
	 * \param[in] user_data  Unique identifier for filename
	 *
	 * \note This is intended to be called after a scheduler connection fails.
	 */
	static void
	save_cib_contents(xmlNode *msg, int call_id, int rc, xmlNode *output,
	                  void *user_data)
	{
	    const char *id = user_data;
	
	    register_fsa_error_adv(C_FSA_INTERNAL, I_ERROR, NULL, NULL, __func__);
	    CRM_CHECK(id != NULL, return);
	
	    if (rc == pcmk_ok) {
	        char *filename = crm_strdup_printf(PE_STATE_DIR "/pe-core-%s.bz2", id);
	
	        if (write_xml_file(output, filename, TRUE) < 0) {
	            crm_err("Could not save Cluster Information Base to %s after scheduler crash",
	                    filename);
	        } else {
	            crm_notice("Saved Cluster Information Base to %s after scheduler crash",
	                       filename);
	        }
	        free(filename);
	    }
	}
	
	/*!
	 * \internal
	 * \brief Respond to scheduler connection failure
	 */
	static void
	handle_disconnect(void)
	{
	    // If we aren't connected to the scheduler, we can't expect a reply
	    controld_expect_sched_reply(NULL);
	
	    if (pcmk_is_set(controld_globals.fsa_input_register, R_PE_REQUIRED)) {
	        int rc = pcmk_ok;
	        char *uuid_str = crm_generate_uuid();
	
	        crm_crit("Lost connection to the scheduler "
	                 CRM_XS " CIB will be saved to " PE_STATE_DIR "/pe-core-%s.bz2",
	                 uuid_str);
	
	        /*
	         * The scheduler died...
	         *
	         * Save the current CIB so that we have a chance of
	         * figuring out what killed it.
	         *
	         * Delay raising the I_ERROR until the query below completes or
	         * 5s is up, whichever comes first.
	         *
	         */
	        rc = controld_globals.cib_conn->cmds->query(controld_globals.cib_conn,
	                                                    NULL, NULL,
	                                                    cib_scope_local);
	        fsa_register_cib_callback(rc, uuid_str, save_cib_contents);
	    }
	
	    controld_clear_fsa_input_flags(R_PE_CONNECTED);
	    controld_trigger_fsa();
	    return;
	}
	
	static void
	handle_reply(pcmk_schedulerd_api_reply_t *reply)
	{
	    const char *msg_ref = NULL;
	
	    if (!AM_I_DC) {
	        return;
	    }
	
	    msg_ref = reply->data.graph.reference;
	
	    if (msg_ref == NULL) {
	        crm_err("%s - Ignoring calculation with no reference", CRM_OP_PECALC);
	
	    } else if (pcmk__str_eq(msg_ref, controld_globals.fsa_pe_ref,
	                            pcmk__str_none)) {
	        ha_msg_input_t fsa_input;
	        xmlNode *crm_data_node;
	
	        controld_stop_sched_timer();
	
	        /* do_te_invoke (which will eventually process the fsa_input we are constructing
	         * here) requires that fsa_input.xml be non-NULL.  That will only happen if
	         * copy_ha_msg_input (which is called by register_fsa_input_adv) sees the
	         * fsa_input.msg that it is expecting. The scheduler's IPC dispatch function
	         * gave us the values we need, we just need to put them into XML.
	         *
	         * The name of the top level element here is irrelevant.  Nothing checks it.
	         */
	        fsa_input.msg = create_xml_node(NULL, "dummy-reply");
	        crm_xml_add(fsa_input.msg, XML_ATTR_REFERENCE, msg_ref);
	        crm_xml_add(fsa_input.msg, F_CRM_TGRAPH_INPUT, reply->data.graph.input);
	
	        crm_data_node = create_xml_node(fsa_input.msg, F_CRM_DATA);
	        add_node_copy(crm_data_node, reply->data.graph.tgraph);
	        register_fsa_input_later(C_IPC_MESSAGE, I_PE_SUCCESS, &fsa_input);
	
	        free_xml(fsa_input.msg);
	
	    } else {
	        crm_info("%s calculation %s is obsolete", CRM_OP_PECALC, msg_ref);
	    }
	}
	
	static void
	scheduler_event_callback(pcmk_ipc_api_t *api, enum pcmk_ipc_event event_type,
	                         crm_exit_t status, void *event_data, void *user_data)
	{
	    pcmk_schedulerd_api_reply_t *reply = event_data;
	
	    switch (event_type) {
	        case pcmk_ipc_event_disconnect:
	            handle_disconnect();
	            break;
	
	        case pcmk_ipc_event_reply:
	            handle_reply(reply);
	            break;
	
	        default:
	            break;
	    }
	}
	
	static bool
	new_schedulerd_ipc_connection(void)
	{
	    int rc;
	
	    controld_set_fsa_input_flags(R_PE_REQUIRED);
	
	    if (schedulerd_api == NULL) {
	        rc = pcmk_new_ipc_api(&schedulerd_api, pcmk_ipc_schedulerd);
	
	        if (rc != pcmk_rc_ok) {
	            crm_err("Error connecting to the scheduler: %s", pcmk_rc_str(rc));
	            return false;
	        }
	    }
	
	    pcmk_register_ipc_callback(schedulerd_api, scheduler_event_callback, NULL);
	
	    rc = pcmk__connect_ipc(schedulerd_api, pcmk_ipc_dispatch_main, 3);
	    if (rc != pcmk_rc_ok) {
	        crm_err("Error connecting to %s: %s",
	                pcmk_ipc_name(schedulerd_api, true), pcmk_rc_str(rc));
	        return false;
	    }
	
	    controld_set_fsa_input_flags(R_PE_CONNECTED);
	    return true;
	}
	
	static void do_pe_invoke_callback(xmlNode *msg, int call_id, int rc,
	                                  xmlNode *output, void *user_data);
	
	/*	 A_PE_START, A_PE_STOP, O_PE_RESTART	*/
	void
	do_pe_control(long long action,
	              enum crmd_fsa_cause cause,
	              enum crmd_fsa_state cur_state,
	              enum crmd_fsa_input current_input, fsa_data_t * msg_data)
	{
	    if (pcmk_is_set(action, A_PE_STOP)) {
	        controld_clear_fsa_input_flags(R_PE_REQUIRED);
	        pcmk_disconnect_ipc(schedulerd_api);
	        handle_disconnect();
	    }
	    if (pcmk_is_set(action, A_PE_START)
	        && !pcmk_is_set(controld_globals.fsa_input_register, R_PE_CONNECTED)) {
	
	        if (cur_state == S_STOPPING) {
	            crm_info("Ignoring request to connect to scheduler while shutting down");
	
	        } else if (!new_schedulerd_ipc_connection()) {
	            crm_warn("Could not connect to scheduler");
	            register_fsa_error(C_FSA_INTERNAL, I_FAIL, NULL);
	        }
	    }
	}
	
	static int fsa_pe_query = 0;
	static mainloop_timer_t *controld_sched_timer = NULL;
	
	// @TODO Make this a configurable cluster option if there's demand for it
	#define SCHED_TIMEOUT_MS (120000)
	
	/*!
	 * \internal
	 * \brief Handle a timeout waiting for scheduler reply
	 *
	 * \param[in] user_data  Ignored
	 *
	 * \return FALSE (indicating that timer should not be restarted)
	 */
	static gboolean
	controld_sched_timeout(gpointer user_data)
	{
	    crm_err("Timeout waiting for reply from scheduler.");
	    if (AM_I_DC) {
	        /* If this node is the DC but can't communicate with the scheduler, just
	         * exit (and likely get fenced) so this node doesn't interfere with any
	         * further DC elections.
	         *
	         * @TODO We could try something less drastic first, like disconnecting
	         * and reconnecting to the scheduler, but something is likely going
	         * seriously wrong, so perhaps it's better to just fail as quickly as
	         * possible.
	         */
	        crmd_exit(CRM_EX_FATAL);
	    }
	    return FALSE;
	}
	
	void
	controld_stop_sched_timer(void)
	{
	    if ((controld_sched_timer != NULL)
	        && (controld_globals.fsa_pe_ref != NULL)) {
	        crm_trace("Stopping timer for scheduler reply %s",
	                  controld_globals.fsa_pe_ref);
	    }
	    mainloop_timer_stop(controld_sched_timer);
	}
	
	/*!
	 * \internal
	 * \brief Set the scheduler request currently being waited on
	 *
	 * \param[in] ref  Request to expect reply to (or NULL for none)
	 *
	 * \note This function takes ownership of \p ref.
	 */
	void
	controld_expect_sched_reply(char *ref)
	{
	    if (ref) {
	        if (controld_sched_timer == NULL) {
	            controld_sched_timer = mainloop_timer_add("scheduler_reply_timer",
	                                                      SCHED_TIMEOUT_MS, FALSE,
	                                                      controld_sched_timeout,
	                                                      NULL);
	        }
	        mainloop_timer_start(controld_sched_timer);
	    } else {
	        controld_stop_sched_timer();
	    }
	    free(controld_globals.fsa_pe_ref);
	    controld_globals.fsa_pe_ref = ref;
	}
	
	/*!
	 * \internal
	 * \brief Free the scheduler reply timer
	 */
	void
	controld_free_sched_timer(void)
	{
	    if (controld_sched_timer != NULL) {
	        mainloop_timer_del(controld_sched_timer);
	        controld_sched_timer = NULL;
	    }
	}
	
	/*	 A_PE_INVOKE	*/
	void
	do_pe_invoke(long long action,
	             enum crmd_fsa_cause cause,
	             enum crmd_fsa_state cur_state,
	             enum crmd_fsa_input current_input, fsa_data_t * msg_data)
	{
	    cib_t *cib_conn = controld_globals.cib_conn;
	
	    if (AM_I_DC == FALSE) {
	        crm_err("Not invoking scheduler because not DC: %s",
	                fsa_action2string(action));
	        return;
	    }
	
	    if (!pcmk_is_set(controld_globals.fsa_input_register, R_PE_CONNECTED)) {
	        if (pcmk_is_set(controld_globals.fsa_input_register, R_SHUTDOWN)) {
	            crm_err("Cannot shut down gracefully without the scheduler");
	            register_fsa_input_before(C_FSA_INTERNAL, I_TERMINATE, NULL);
	
	        } else {
	            crm_info("Waiting for the scheduler to connect");
	            crmd_fsa_stall(FALSE);
	            controld_set_fsa_action_flags(A_PE_START);
	            controld_trigger_fsa();
	        }
	        return;
	    }
	
	    if (cur_state != S_POLICY_ENGINE) {
	        crm_notice("Not invoking scheduler because in state %s",
	                   fsa_state2string(cur_state));
	        return;
	    }
	    if (!pcmk_is_set(controld_globals.fsa_input_register, R_HAVE_CIB)) {
	        crm_err("Attempted to invoke scheduler without consistent Cluster Information Base!");
	
	        /* start the join from scratch */
	        register_fsa_input_before(C_FSA_INTERNAL, I_ELECTION, NULL);
	        return;
	    }
	
	    fsa_pe_query = cib_conn->cmds->query(cib_conn, NULL, NULL, cib_scope_local);
	
	    crm_debug("Query %d: Requesting the current CIB: %s", fsa_pe_query,
	              fsa_state2string(controld_globals.fsa_state));
	
	    controld_expect_sched_reply(NULL);
	    fsa_register_cib_callback(fsa_pe_query, NULL, do_pe_invoke_callback);
	}
	
	static void
	force_local_option(xmlNode *xml, const char *attr_name, const char *attr_value)
	{
	    int max = 0;
	    int lpc = 0;
	    const char *xpath_base = NULL;
	    char *xpath_string = NULL;
	    xmlXPathObjectPtr xpathObj = NULL;
	
	    xpath_base = pcmk_cib_xpath_for(XML_CIB_TAG_CRMCONFIG);
	    if (xpath_base == NULL) {
	        crm_err(XML_CIB_TAG_CRMCONFIG " CIB element not known (bug?)");
	        return;
	    }
	
	    xpath_string = crm_strdup_printf("%s//%s//nvpair[@name='%s']",
	                                     xpath_base, XML_CIB_TAG_PROPSET,
	                                     attr_name);
	    xpathObj = xpath_search(xml, xpath_string);
	    max = numXpathResults(xpathObj);
	    free(xpath_string);
	
	    for (lpc = 0; lpc < max; lpc++) {
	        xmlNode *match = getXpathResult(xpathObj, lpc);
	        crm_trace("Forcing %s/%s = %s", ID(match), attr_name, attr_value);
	        crm_xml_add(match, XML_NVPAIR_ATTR_VALUE, attr_value);
	    }
	
	    if(max == 0) {
	        xmlNode *configuration = NULL;
	        xmlNode *crm_config = NULL;
	        xmlNode *cluster_property_set = NULL;
	
	        crm_trace("Creating %s-%s for %s=%s",
	                  CIB_OPTIONS_FIRST, attr_name, attr_name, attr_value);
	
	        configuration = pcmk__xe_match(xml, XML_CIB_TAG_CONFIGURATION, NULL,
	                                       NULL);
	        if (configuration == NULL) {
	            configuration = create_xml_node(xml, XML_CIB_TAG_CONFIGURATION);
	        }
	
	        crm_config = pcmk__xe_match(configuration, XML_CIB_TAG_CRMCONFIG, NULL,
	                                    NULL);
	        if (crm_config == NULL) {
	            crm_config = create_xml_node(configuration, XML_CIB_TAG_CRMCONFIG);
	        }
	
	        cluster_property_set = pcmk__xe_match(crm_config, XML_CIB_TAG_PROPSET,
	                                              NULL, NULL);
	        if (cluster_property_set == NULL) {
	            cluster_property_set = create_xml_node(crm_config, XML_CIB_TAG_PROPSET);
	            crm_xml_add(cluster_property_set, XML_ATTR_ID, CIB_OPTIONS_FIRST);
	        }
	
	        xml = create_xml_node(cluster_property_set, XML_CIB_TAG_NVPAIR);
	
	        crm_xml_set_id(xml, "%s-%s", CIB_OPTIONS_FIRST, attr_name);
	        crm_xml_add(xml, XML_NVPAIR_ATTR_NAME, attr_name);
	        crm_xml_add(xml, XML_NVPAIR_ATTR_VALUE, attr_value);
	    }
	    freeXpathObject(xpathObj);
	}
	
	static void
	do_pe_invoke_callback(xmlNode * msg, int call_id, int rc, xmlNode * output, void *user_data)
	{
	    char *ref = NULL;
	    pid_t watchdog = pcmk__locate_sbd();
	

	    if (rc != pcmk_ok) {
	        crm_err("Could not retrieve the Cluster Information Base: %s "
	                CRM_XS " rc=%d call=%d", pcmk_strerror(rc), rc, call_id);
	        register_fsa_error_adv(C_FSA_INTERNAL, I_ERROR, NULL, NULL, __func__);
	        return;
	

	    } else if (call_id != fsa_pe_query) {
	        crm_trace("Skipping superseded CIB query: %d (current=%d)", call_id, fsa_pe_query);
	        return;
	

	    } else if (!AM_I_DC
	               || !pcmk_is_set(controld_globals.fsa_input_register,
	                               R_PE_CONNECTED)) {
	        crm_debug("No need to invoke the scheduler anymore");
	        return;
	

	    } else if (controld_globals.fsa_state != S_POLICY_ENGINE) {
	        crm_debug("Discarding scheduler request in state: %s",
	                  fsa_state2string(controld_globals.fsa_state));
	        return;
	
	    /* this callback counts as 1 */

	    } else if (num_cib_op_callbacks() > 1) {
	        crm_debug("Re-asking for the CIB: %d other peer updates still pending",
	                  (num_cib_op_callbacks() - 1));
	        sleep(1);
	        controld_set_fsa_action_flags(A_PE_INVOKE);
	        controld_trigger_fsa();
	        return;
	    }
	

	    CRM_LOG_ASSERT(output != NULL);
	
	    /* Refresh the remote node cache and the known node cache when the
	     * scheduler is invoked */
	    pcmk__refresh_node_caches_from_cib(output);
	
	    crm_xml_add(output, XML_ATTR_DC_UUID, controld_globals.our_uuid);
	    pcmk__xe_set_bool_attr(output, XML_ATTR_HAVE_QUORUM,
	                           pcmk_is_set(controld_globals.flags,
	                                       controld_has_quorum));
	

	    force_local_option(output, XML_ATTR_HAVE_WATCHDOG, pcmk__btoa(watchdog));
	

	    if (pcmk_is_set(controld_globals.flags, controld_ever_had_quorum)
	        && !crm_have_quorum) {
	        crm_xml_add_int(output, XML_ATTR_QUORUM_PANIC, 1);
	    }
	

	    rc = pcmk_rc2legacy(pcmk_schedulerd_api_graph(schedulerd_api, output, &ref));
	

	    if (rc < 0) {
	        crm_err("Could not contact the scheduler: %s " CRM_XS " rc=%d",
	                pcmk_strerror(rc), rc);
	        register_fsa_error_adv(C_FSA_INTERNAL, I_ERROR, NULL, NULL, __func__);

	    } else {
	        CRM_ASSERT(ref != NULL);
	        controld_expect_sched_reply(ref);
	        crm_debug("Invoking the scheduler: query=%d, ref=%s, seq=%llu, "
	                  "quorate=%s", fsa_pe_query, controld_globals.fsa_pe_ref,
	                  crm_peer_seq, pcmk__btoa(pcmk_is_set(controld_globals.flags,
	                                                       controld_has_quorum)));
	    }

	}