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

#include "plugin_proc.h"

struct edac_count {
    bool updated;
    char *filename;
    procfile *ff;
    kernel_uint_t count;
    RRDDIM *rd;
};

struct edac_dimm {
	char *name;

    struct edac_count ce;
    struct edac_count ue;

    RRDSET *st;

    struct edac_dimm *prev, *next;
};

struct mc {
    char *name;

    struct edac_count ce;
    struct edac_count ue;
    struct edac_count ce_noinfo;
    struct edac_count ue_noinfo;

    RRDSET *st;

    struct edac_dimm *dimms;

    struct mc *prev, *next;
};

static struct mc *mc_root = NULL;
static char *mc_dirname = NULL;

static void find_all_mc() {
    char name[FILENAME_MAX + 1];
    snprintfz(name, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/devices/system/edac/mc");
    mc_dirname = config_get("plugin:proc:/sys/devices/system/edac/mc", "directory to monitor", name);

    DIR *dir = opendir(mc_dirname);
    if(unlikely(!dir)) {
        collector_error("Cannot read EDAC memory errors directory '%s'", mc_dirname);
        return;
    }

    struct dirent *de = NULL;
    while((de = readdir(dir))) {
        if(de->d_type == DT_DIR && de->d_name[0] == 'm' && de->d_name[1] == 'c' && isdigit(de->d_name[2])) {
            struct mc *m = callocz(1, sizeof(struct mc));
            m->name = strdupz(de->d_name);

            struct stat st;

            snprintfz(name, FILENAME_MAX, "%s/%s/ce_count", mc_dirname, de->d_name);
            if(stat(name, &st) != -1)
                m->ce.filename = strdupz(name);

            snprintfz(name, FILENAME_MAX, "%s/%s/ue_count", mc_dirname, de->d_name);
            if(stat(name, &st) != -1)
                m->ue.filename = strdupz(name);

            snprintfz(name, FILENAME_MAX, "%s/%s/ce_noinfo_count", mc_dirname, de->d_name);
            if(stat(name, &st) != -1)
                m->ce_noinfo.filename = strdupz(name);

            snprintfz(name, FILENAME_MAX, "%s/%s/ue_noinfo_count", mc_dirname, de->d_name);
            if(stat(name, &st) != -1)
                m->ue_noinfo.filename = strdupz(name);

            if(!m->ce.filename && !m->ue.filename && !m->ce_noinfo.filename && !m->ue_noinfo.filename) {
                freez(m->name);
                freez(m);
            }
            else
                DOUBLE_LINKED_LIST_APPEND_ITEM_UNSAFE(mc_root, m, prev, next);
        }
    }
    closedir(dir);

    for(struct mc *m = mc_root; m ;m = m->next) {
        snprintfz(name, FILENAME_MAX, "%s/%s", mc_dirname, m->name);
        dir = opendir(name);
        if(!dir) {
            collector_error("Cannot read EDAC memory errors directory '%s'", name);
            continue;
        }

        while((de = readdir(dir))) {
            // it can be dimmX or rankX directory
            // https://www.kernel.org/doc/html/v5.0/admin-guide/ras.html#f5

            if (de->d_type == DT_DIR &&
                ((strncmp(de->d_name, "rank", 4) == 0 || strncmp(de->d_name, "dimm", 4) == 0)) &&
                isdigit(de->d_name[4])) {

                struct edac_dimm *d = callocz(1, sizeof(struct edac_dimm));
                d->name = strdupz(de->d_name);

                struct stat st;

                snprintfz(name, FILENAME_MAX, "%s/%s/%s/dimm_ce_count", mc_dirname, m->name, de->d_name);
                if(stat(name, &st) != -1)
                    d->ce.filename = strdupz(name);

                snprintfz(name, FILENAME_MAX, "%s/%s/%s/dimm_ue_count", mc_dirname, m->name, de->d_name);
                if(stat(name, &st) != -1)
                    d->ue.filename = strdupz(name);

                if(!d->ce.filename && !d->ue.filename) {
                    freez(d->name);
                    freez(d);
                }
                else
                    DOUBLE_LINKED_LIST_APPEND_ITEM_UNSAFE(m->dimms, d, prev, next);
            }
        }
        closedir(dir);
    }
}

static kernel_uint_t read_edac_count(struct edac_count *t) {
    t->updated = false;
    t->count = 0;

    if(t->filename) {
        if(unlikely(!t->ff)) {
            t->ff = procfile_open(t->filename, " \t", PROCFILE_FLAG_DEFAULT);
            if(unlikely(!t->ff))
                return 0;
        }

        t->ff = procfile_readall(t->ff);
        if(unlikely(!t->ff || procfile_lines(t->ff) < 1 || procfile_linewords(t->ff, 0) < 1))
            return 0;

        t->count = str2ull(procfile_lineword(t->ff, 0, 0), NULL);
        t->updated = true;
    }

    return t->count;
}

static bool read_edac_mc_file(const char *mc, const char *filename, char *out, size_t out_size) {
    char f[FILENAME_MAX + 1];
    snprintfz(f, FILENAME_MAX, "%s/%s/%s", mc_dirname, mc, filename);
    if(read_file(f, out, out_size) != 0) {
        collector_error("EDAC: cannot read file '%s'", f);
        return false;
    }
    return true;
}

static bool read_edac_mc_rank_file(const char *mc, const char *rank, const char *filename, char *out, size_t out_size) {
    char f[FILENAME_MAX + 1];
    snprintfz(f, FILENAME_MAX, "%s/%s/%s/%s", mc_dirname, mc, rank, filename);
    if(read_file(f, out, out_size) != 0) {
        collector_error("EDAC: cannot read file '%s'", f);
        return false;
    }
    return true;
}

int do_proc_sys_devices_system_edac_mc(int update_every, usec_t dt __maybe_unused) {
    if(unlikely(!mc_root)) {
        find_all_mc();

        if(!mc_root)
            // don't call this again
            return 1;
    }

    for(struct mc *m = mc_root; m; m = m->next) {
        read_edac_count(&m->ce);
        read_edac_count(&m->ce_noinfo);
        read_edac_count(&m->ue);
        read_edac_count(&m->ue_noinfo);

        for(struct edac_dimm *d = m->dimms; d ;d = d->next) {
            read_edac_count(&d->ce);
            read_edac_count(&d->ue);
        }
    }

    // --------------------------------------------------------------------

    for(struct mc *m = mc_root; m ; m = m->next) {
        if(unlikely(!m->ce.updated && !m->ue.updated && !m->ce_noinfo.updated && !m->ue_noinfo.updated))
            continue;

        if(unlikely(!m->st)) {
            char id[RRD_ID_LENGTH_MAX + 1];
            snprintfz(id, RRD_ID_LENGTH_MAX, "edac_%s", m->name);
            m->st = rrdset_create_localhost(
                    "mem"
                    , id
                    , NULL
                    , "edac"
                    , "mem.edac_mc"
                    , "Memory Controller (MC) Error Detection And Correction (EDAC) Errors"
                    , "errors/s"
                    , PLUGIN_PROC_NAME
                    , "/sys/devices/system/edac/mc"
                    , NETDATA_CHART_PRIO_MEM_HW_ECC_CE
                    , update_every
                    , RRDSET_TYPE_LINE
            );

            rrdlabels_add(m->st->rrdlabels, "controller", m->name, RRDLABEL_SRC_AUTO);

            char buffer[1024 + 1];

            if(read_edac_mc_file(m->name, "mc_name", buffer, 1024))
                rrdlabels_add(m->st->rrdlabels, "mc_name", buffer, RRDLABEL_SRC_AUTO);

            if(read_edac_mc_file(m->name, "size_mb", buffer, 1024))
                rrdlabels_add(m->st->rrdlabels, "size_mb", buffer, RRDLABEL_SRC_AUTO);

            if(read_edac_mc_file(m->name, "max_location", buffer, 1024))
                rrdlabels_add(m->st->rrdlabels, "max_location", buffer, RRDLABEL_SRC_AUTO);

            m->ce.rd = rrddim_add(m->st, "correctable", NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            m->ue.rd = rrddim_add(m->st, "uncorrectable", NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            m->ce_noinfo.rd = rrddim_add(m->st, "correctable_noinfo", NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            m->ue_noinfo.rd = rrddim_add(m->st, "uncorrectable_noinfo", NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
        }

        rrddim_set_by_pointer(m->st, m->ce.rd, (collected_number)m->ce.count);
        rrddim_set_by_pointer(m->st, m->ue.rd, (collected_number)m->ue.count);
        rrddim_set_by_pointer(m->st, m->ce_noinfo.rd, (collected_number)m->ce_noinfo.count);
        rrddim_set_by_pointer(m->st, m->ue_noinfo.rd, (collected_number)m->ue_noinfo.count);

        rrdset_done(m->st);

        for(struct edac_dimm *d = m->dimms; d ;d = d->next) {
            if(unlikely(!d->ce.updated && !d->ue.updated))
                continue;

            if(unlikely(!d->st)) {
                char id[RRD_ID_LENGTH_MAX + 1];
                snprintfz(id, RRD_ID_LENGTH_MAX, "edac_%s_%s", m->name, d->name);
                d->st = rrdset_create_localhost(
                        "mem"
                		, id
                		, NULL
                		, "edac"
                        , "mem.edac_mc_dimm"
                		, "DIMM Error Detection And Correction (EDAC) Errors"
                        , "errors/s"
                        , PLUGIN_PROC_NAME
                        , "/sys/devices/system/edac/mc"
                        , NETDATA_CHART_PRIO_MEM_HW_ECC_CE + 1
                        , update_every
                        , RRDSET_TYPE_LINE
                );

                rrdlabels_add(d->st->rrdlabels, "controller", m->name, RRDLABEL_SRC_AUTO);
                rrdlabels_add(d->st->rrdlabels, "dimm", d->name, RRDLABEL_SRC_AUTO);

                char buffer[1024 + 1];

                if (read_edac_mc_rank_file(m->name, d->name, "dimm_dev_type", buffer, 1024))
                    rrdlabels_add(d->st->rrdlabels, "dimm_dev_type", buffer, RRDLABEL_SRC_AUTO);

                if (read_edac_mc_rank_file(m->name, d->name, "dimm_edac_mode", buffer, 1024))
                    rrdlabels_add(d->st->rrdlabels, "dimm_edac_mode", buffer, RRDLABEL_SRC_AUTO);

                if (read_edac_mc_rank_file(m->name, d->name, "dimm_label", buffer, 1024))
                    rrdlabels_add(d->st->rrdlabels, "dimm_label", buffer, RRDLABEL_SRC_AUTO);

                if (read_edac_mc_rank_file(m->name, d->name, "dimm_location", buffer, 1024))
                    rrdlabels_add(d->st->rrdlabels, "dimm_location", buffer, RRDLABEL_SRC_AUTO);

                if (read_edac_mc_rank_file(m->name, d->name, "dimm_mem_type", buffer, 1024))
                    rrdlabels_add(d->st->rrdlabels, "dimm_mem_type", buffer, RRDLABEL_SRC_AUTO);

                if (read_edac_mc_rank_file(m->name, d->name, "size", buffer, 1024))
                    rrdlabels_add(d->st->rrdlabels, "size", buffer, RRDLABEL_SRC_AUTO);

                d->ce.rd = rrddim_add(d->st, "correctable", NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
                d->ue.rd = rrddim_add(d->st, "uncorrectable", NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
            }

            rrddim_set_by_pointer(d->st, d->ce.rd, (collected_number)d->ce.count);
            rrddim_set_by_pointer(d->st, d->ue.rd, (collected_number)d->ue.count);

            rrdset_done(d->st);
        }
    }

    return 0;
}