// SPDX-License-Identifier: GPL-3.0-or-later

#include "plugin_proc.h"

#define PLUGIN_PROC_MODULE_LOADAVG_NAME "/proc/loadavg"
#define CONFIG_SECTION_PLUGIN_PROC_LOADAVG "plugin:" PLUGIN_PROC_CONFIG_NAME ":" PLUGIN_PROC_MODULE_LOADAVG_NAME

// linux calculates this once every 5 seconds
#define MIN_LOADAVG_UPDATE_EVERY 5

int do_proc_loadavg(int update_every, usec_t dt) {
    static procfile *ff = NULL;
    static int do_loadavg = -1, do_all_processes = -1;
    static usec_t next_loadavg_dt = 0;

    if(unlikely(!ff)) {
        char filename[FILENAME_MAX + 1];
        snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/proc/loadavg");

        ff = procfile_open(config_get(CONFIG_SECTION_PLUGIN_PROC_LOADAVG, "filename to monitor", filename), " \t,:|/", PROCFILE_FLAG_DEFAULT);
        if(unlikely(!ff))
            return 1;
    }

    ff = procfile_readall(ff);
    if(unlikely(!ff))
        return 0; // we return 0, so that we will retry to open it next time

    if(unlikely(do_loadavg == -1)) {
        do_loadavg          = config_get_boolean(CONFIG_SECTION_PLUGIN_PROC_LOADAVG, "enable load average", 1);
        do_all_processes    = config_get_boolean(CONFIG_SECTION_PLUGIN_PROC_LOADAVG, "enable total processes", 1);
    }

    if(unlikely(procfile_lines(ff) < 1)) {
        collector_error("/proc/loadavg has no lines.");
        return 1;
    }
    if(unlikely(procfile_linewords(ff, 0) < 6)) {
        collector_error("/proc/loadavg has less than 6 words in it.");
        return 1;
    }

    double load1 = strtod(procfile_lineword(ff, 0, 0), NULL);
    double load5 = strtod(procfile_lineword(ff, 0, 1), NULL);
    double load15 = strtod(procfile_lineword(ff, 0, 2), NULL);

    //unsigned long long running_processes  = str2ull(procfile_lineword(ff, 0, 3));
    unsigned long long active_processes     = str2ull(procfile_lineword(ff, 0, 4));
    
    //get system pid_max
    unsigned long long max_processes        = get_system_pid_max();
    //
    //unsigned long long next_pid           = str2ull(procfile_lineword(ff, 0, 5));

    if(next_loadavg_dt <= dt) {
        if(likely(do_loadavg)) {
            static RRDSET *load_chart = NULL;
            static RRDDIM *rd_load1 = NULL, *rd_load5 = NULL, *rd_load15 = NULL;

            if(unlikely(!load_chart)) {
                load_chart = rrdset_create_localhost(
                        "system"
                        , "load"
                        , NULL
                        , "load"
                        , NULL
                        , "System Load Average"
                        , "load"
                        , PLUGIN_PROC_NAME
                        , PLUGIN_PROC_MODULE_LOADAVG_NAME
                        , NETDATA_CHART_PRIO_SYSTEM_LOAD
                        , (update_every < MIN_LOADAVG_UPDATE_EVERY) ? MIN_LOADAVG_UPDATE_EVERY : update_every
                        , RRDSET_TYPE_LINE
                );

                rd_load1  = rrddim_add(load_chart, "load1",  NULL, 1, 1000, RRD_ALGORITHM_ABSOLUTE);
                rd_load5  = rrddim_add(load_chart, "load5",  NULL, 1, 1000, RRD_ALGORITHM_ABSOLUTE);
                rd_load15 = rrddim_add(load_chart, "load15", NULL, 1, 1000, RRD_ALGORITHM_ABSOLUTE);
            }

            rrddim_set_by_pointer(load_chart, rd_load1, (collected_number) (load1 * 1000));
            rrddim_set_by_pointer(load_chart, rd_load5, (collected_number) (load5 * 1000));
            rrddim_set_by_pointer(load_chart, rd_load15, (collected_number) (load15 * 1000));
            rrdset_done(load_chart);

            next_loadavg_dt = load_chart->update_every * USEC_PER_SEC;
        }
        else
            next_loadavg_dt =  MIN_LOADAVG_UPDATE_EVERY * USEC_PER_SEC;
    }
    else
        next_loadavg_dt -= dt;


    if(likely(do_all_processes)) {
        static RRDSET *processes_chart = NULL;
        static RRDDIM *rd_active = NULL;
        static const RRDSETVAR_ACQUIRED *rd_pidmax;

        if(unlikely(!processes_chart)) {
            processes_chart = rrdset_create_localhost(
                    "system"
                    , "active_processes"
                    , NULL
                    , "processes"
                    , NULL
                    , "System Active Processes"
                    , "processes"
                    , PLUGIN_PROC_NAME
                    , PLUGIN_PROC_MODULE_LOADAVG_NAME
                    , NETDATA_CHART_PRIO_SYSTEM_ACTIVE_PROCESSES
                    , update_every
                    , RRDSET_TYPE_LINE
            );

            rd_active = rrddim_add(processes_chart, "active", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
            rd_pidmax = rrdsetvar_custom_chart_variable_add_and_acquire(processes_chart, "pidmax");
        }

        rrddim_set_by_pointer(processes_chart, rd_active, active_processes);
        rrdsetvar_custom_chart_variable_set(processes_chart, rd_pidmax, max_processes);
        rrdset_done(processes_chart);
    }

    return 0;
}