/*
 * Copyright (c) 2018 MariaDB Corporation Ab
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
 *
 * Change Date: 2025-02-16
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2 or later of the General
 * Public License.
 */
#pragma once

/**
 * @file galeramon.hh - The Galera cluster monitor
 */

#include <maxscale/ccdefs.hh>
#include <unordered_map>
#include <maxscale/monitor.hh>

/**
 *  Galera status variables
 */
struct GaleraNode
{
    int         joined;         /**< Node is in sync with the cluster */
    int         local_index;    /**< Node index */
    int         local_state;    /**< Node state */
    int         cluster_size;   /**< The cluster size*/
    std::string cluster_uuid;   /**< Cluster UUID */
    std::string gtid_binlog_pos;
    std::string gtid_current_pos;
    bool        read_only = false;
    int         master_id;
    int         server_id;
};

typedef std::unordered_map<mxs::MonitorServer*, GaleraNode> NodeMap;

class GaleraMonitor : public maxscale::MonitorWorkerSimple
{
public:
    GaleraMonitor(const GaleraMonitor&) = delete;
    GaleraMonitor& operator=(const GaleraMonitor&) = delete;

    ~GaleraMonitor();
    static GaleraMonitor* create(const std::string& name, const std::string& module);
    void                  diagnostics(DCB* dcb) const;
    json_t*               diagnostics_json() const;

protected:
    bool configure(const MXS_CONFIG_PARAMETER* param);
    bool has_sufficient_permissions();
    void update_server_status(mxs::MonitorServer* monitored_server);
    void pre_tick();
    void post_tick();

private:
    int  m_disableMasterFailback;       /**< Monitor flag for Galera Cluster Master failback */
    int  m_availableWhenDonor;          /**< Monitor flag for Galera Cluster Donor availability */
    bool m_disableMasterRoleSetting;    /**< Monitor flag to disable setting master role */
    bool m_root_node_as_master;         /**< Whether we require that the Master should
                                         * have a wsrep_local_index of 0 */
    bool m_use_priority;                /**< Use server priorities */
    bool m_set_donor_nodes;             /**< set the wrep_sst_donor variable with an
                                         * ordered list of nodes */
    std::string m_cluster_uuid;         /**< The Cluster UUID */
    bool        m_log_no_members;       /**< Should we log if no member are found. */
    NodeMap     m_info;                 /**< Contains Galera Cluster variables of all nodes */
    NodeMap     m_prev_info;            /**< Contains the info from the previous tick */
    int         m_cluster_size;         /**< How many nodes in the cluster */

    // Prevents concurrent use that might occur during the diagnostics_json call
    mutable std::mutex m_lock;

    GaleraMonitor(const std::string& name, const std::string& module);

    bool detect_cluster_size(const int n_nodes,
                             const char* candidate_uuid,
                             const int candidate_size);
    mxs::MonitorServer* get_candidate_master();
    void                set_galera_cluster();
    void                update_sst_donor_nodes(int is_cluster);
    void                calculate_cluster();
};