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

#include "plugin_proc.h"

#define PLUGIN_PROC_MODULE_MDSTAT_NAME "/proc/mdstat"

struct raid {
    int used;
    char *name;
    RRDDIM *rd_health;
    unsigned long long failed_disks;

    RRDSET *st_disks;
    RRDDIM *rd_total;
    RRDDIM *rd_inuse;
    unsigned long long total_disks;
    unsigned long long inuse_disks;

    RRDSET *st_operation;
    RRDDIM *rd_check;
    RRDDIM *rd_resync;
    RRDDIM *rd_recovery;
    RRDDIM *rd_reshape;
    unsigned long long check;
    unsigned long long resync;
    unsigned long long recovery;
    unsigned long long reshape;

    RRDSET *st_finish;
    RRDDIM *rd_finish_in;
    unsigned long long finish_in;

    RRDSET *st_speed;
    RRDDIM *rd_speed;
    unsigned long long speed;

    char *mismatch_cnt_filename;
    RRDSET *st_mismatch_cnt;
    RRDDIM *rd_mismatch_cnt;
    unsigned long long mismatch_cnt;
};

static inline char *remove_trailing_chars(char *s, char c) {
    while(*s) {
        if(unlikely(*s == c)) {
            *s = '\0';
        }
        s++;
    }
    return s;
}

int do_proc_mdstat(int update_every, usec_t dt) {
    (void)dt;
    static procfile *ff = NULL;
    static char *mdstat_filename = NULL, *mismatch_cnt_filename = NULL;
    static struct raid *raids = NULL;
    static size_t raids_num = 0, raids_allocated = 0;
    size_t raid_idx = 0;

    if(unlikely(!mismatch_cnt_filename)) {
        char filename[FILENAME_MAX + 1];
        snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/block/%s/md/mismatch_cnt");
        mismatch_cnt_filename = config_get("plugin:proc:/proc/mdstat", "mismatch_cnt filename to monitor", filename);
    }

    if(unlikely(!ff)) {
        char filename[FILENAME_MAX + 1];
        snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/proc/mdstat");
        mdstat_filename = config_get("plugin:proc:/proc/mdstat", "filename to monitor", filename);
        ff = procfile_open(mdstat_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 opening it next time

    size_t lines = procfile_lines(ff);
    size_t words = 0;

    if(unlikely(lines < 2)) {
        error("Cannot read /proc/mdstat. Expected 2 or more lines, read %zu.", lines);
        return 1;
    }

    // find how many raids are there
    size_t l;
    raids_num = 0;
    for(l = 1; l < lines - 2 ; l++) {
       if(unlikely(procfile_lineword(ff, l, 1)[0] == 'a')) // check if the raid is active
            raids_num++;
    }

    if(unlikely(!raids_num)) return 0; // we return 0, so that we will retry searching for raids next time

    // allocate the memory we need;
    if(unlikely(raids_num != raids_allocated)) {
        for(raid_idx = 0; raid_idx < raids_allocated; raid_idx++) {
            struct raid *raid = &raids[raid_idx];
            freez(raid->name);
            freez(raid->mismatch_cnt_filename);
        }
        raids = (struct raid *)reallocz(raids, raids_num * sizeof(struct raid));
        raids_allocated = raids_num;
        memset(raids, 0, raids_num * sizeof(struct raid));
    }

    // loop through all lines except the first and the last ones
    for(l = 1, raid_idx = 0; l < (lines - 2) && raid_idx < raids_num; l++) {
        struct raid *raid = &raids[raid_idx];
        raid->used = 0;

        words = procfile_linewords(ff, l);
        if(unlikely(words < 2)) continue;

        if(unlikely(procfile_lineword(ff, l, 1)[0] != 'a')) continue;
        if(!raid->name) {
            raid->name = strdupz(procfile_lineword(ff, l, 0));
        }
        else if(strcmp(raid->name, procfile_lineword(ff, l, 0))) {
            freez(raid->name);
            freez(raid->mismatch_cnt_filename);
            memset(raid, 0, sizeof(struct raid));
            raid->name = strdupz(procfile_lineword(ff, l, 0));
        }
        if(unlikely(!raid->name || !raid->name[0])) continue;
        raid_idx++;

        // check if raid has disk status
        l++;
        words = procfile_linewords(ff, l);
        if(words < 2 || procfile_lineword(ff, l, words - 1)[0] != '[') {
            continue;
        }

        // split inuse and total number of disks
        char *s = NULL, *str_total = NULL, *str_inuse = NULL;

        s = procfile_lineword(ff, l, words - 2);
        if(unlikely(s[0] != '[')) {
            error("Cannot read /proc/mdstat raid health status. Unexpected format: missing opening bracket.");
            continue;
        }
        str_total = ++s;
        while(*s) {
            if(unlikely(*s == '/')) {
                *s = '\0';
                str_inuse = s + 1;
            }
            else if(unlikely(*s == ']')) {
                *s = '\0';
                break;
            }
            s++;
        }
        if(unlikely(str_total[0] == '\0' || str_inuse[0] == '\0')) {
            error("Cannot read /proc/mdstat raid health status. Unexpected format.");
            continue;
        }

        raid->inuse_disks = str2ull(str_inuse);
        raid->total_disks = str2ull(str_total);
        raid->failed_disks = raid->total_disks - raid->inuse_disks;

        raid->used = 1;

        raid->check = 0;
        raid->resync = 0;
        raid->recovery = 0;
        raid->reshape = 0;
        raid->finish_in = 0;
        raid->speed = 0;

        // check if any operation is performed on the raid
        l++;
        words = procfile_linewords(ff, l);
        if(likely(words < 2)) continue;
        if(unlikely(words < 7)) {
            error("Cannot read /proc/mdstat line. Expected 7 params, read %zu.", words);
            continue;
        }
        if(unlikely(procfile_lineword(ff, l, 0)[0] != '[')) continue;
        char *word;

        word = procfile_lineword(ff, l, 3);
        remove_trailing_chars(word, '%');

        unsigned long long percentage = (unsigned long long)(str2ld(word, NULL) * 100);
        // possible operations: check, resync, recovery, reshape
        // 4-th character is unique for each operation so it is checked
        switch(procfile_lineword(ff, l, 1)[3]) {
            case 'c': // check
                raid->check = percentage;
                break;
            case 'y': // resync
                raid->resync = percentage;
                break;
            case 'o': // recovery
                raid->recovery = percentage;
                break;
            case 'h': // reshape
                raid->reshape = percentage;
                break;
        }

        word = procfile_lineword(ff, l, 5);
        s = remove_trailing_chars(word, 'm'); // remove trailing "min"

        word += 7; // skip leading "finish="

        if(likely(s > word))
            raid->finish_in = (unsigned long long)(str2ld(word, NULL) * 60);

        word = procfile_lineword(ff, l, 6);
        s = remove_trailing_chars(word, 'K'); // remove trailing "K/sec"

        word += 6; // skip leading "speed="

        if(likely(s > word))
            raid->speed = str2ull(word);
    }

    // read mismatch_cnt files
    for(raid_idx = 0; raid_idx < raids_num ; raid_idx++) {
        char filename[FILENAME_MAX + 1];
        struct raid *raid = &raids[raid_idx];

        if(likely(raid->used)) {
            if(!raid->mismatch_cnt_filename) {
                snprintfz(filename, FILENAME_MAX, mismatch_cnt_filename, raid->name);
                raid->mismatch_cnt_filename = strdupz(filename);
            }
            if(unlikely(read_single_number_file(raid->mismatch_cnt_filename, &raid->mismatch_cnt))) {
                error("Cannot read file '%s'", raid->mismatch_cnt_filename);
                return 1;
            }
        }
    }

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

    static RRDSET *st_mdstat_health = NULL;
    if(unlikely(!st_mdstat_health))
        st_mdstat_health = rrdset_create_localhost(
                "mdstat"
                , "mdstat_health"
                , NULL
                , "health"
                , "md.health"
                , "Faulty Devices In MD"
                , "failed disks"
                , PLUGIN_PROC_NAME
                , PLUGIN_PROC_MODULE_MDSTAT_NAME
                , NETDATA_CHART_PRIO_MDSTAT_HEALTH
                , update_every
                , RRDSET_TYPE_LINE
        );
    else
        rrdset_next(st_mdstat_health);

    for(raid_idx = 0; raid_idx < raids_num; raid_idx++) {
        struct raid *raid = &raids[raid_idx];

        if(likely(raid->used)) {
            if(unlikely(!raid->rd_health && !(raid->rd_health = rrddim_find(st_mdstat_health, raid->name))))
                    raid->rd_health = rrddim_add(st_mdstat_health, raid->name, NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);

            rrddim_set_by_pointer(st_mdstat_health, raid->rd_health, raid->failed_disks);
        }
    }

    rrdset_done(st_mdstat_health);

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

    for(raid_idx = 0; raid_idx < raids_num ; raid_idx++) {
        struct raid *raid = &raids[raid_idx];
        char id[50 + 1];
        char family[50 + 1];

        if(likely(raid->used)) {
            snprintfz(id, 50, "%s_disks", raid->name);

            if(unlikely(!raid->st_disks && !(raid->st_disks = rrdset_find_byname_localhost(id)))) {
                snprintfz(family, 50, "%s", raid->name);
                raid->st_disks = rrdset_create_localhost(
                        "mdstat"
                        , id
                        , NULL
                        , family
                        , "md.disks"
                        , "Disks Stats"
                        , "disks"
                        , PLUGIN_PROC_NAME
                        , PLUGIN_PROC_MODULE_MDSTAT_NAME
                        , NETDATA_CHART_PRIO_MDSTAT_DISKS + raid_idx * 10
                        , update_every
                        , RRDSET_TYPE_STACKED
                );
            }
            else
                rrdset_next(raid->st_disks);

            if(unlikely(!raid->rd_inuse && !(raid->rd_inuse = rrddim_find(raid->st_disks, "inuse"))))
                raid->rd_inuse = rrddim_add(raid->st_disks, "inuse", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
            if(unlikely(!raid->rd_total && !(raid->rd_total = rrddim_find(raid->st_disks, "total"))))
                raid->rd_total = rrddim_add(raid->st_disks, "total", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);

            rrddim_set_by_pointer(raid->st_disks, raid->rd_inuse, raid->inuse_disks);
            rrddim_set_by_pointer(raid->st_disks, raid->rd_total, raid->total_disks);

            rrdset_done(raid->st_disks);

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

            snprintfz(id, 50, "%s_mismatch", raid->name);

            if(unlikely(!raid->st_mismatch_cnt && !(raid->st_mismatch_cnt = rrdset_find_byname_localhost(id)))) {
                snprintfz(family, 50, "%s", raid->name);

                raid->st_mismatch_cnt = rrdset_create_localhost(
                        "mdstat"
                        , id
                        , NULL
                        , family
                        , "md.mismatch_cnt"
                        , "Mismatch Count"
                        , "unsynchronized blocks"
                        , PLUGIN_PROC_NAME
                        , PLUGIN_PROC_MODULE_MDSTAT_NAME
                        , NETDATA_CHART_PRIO_MDSTAT_MISMATCH + raid_idx * 10
                        , update_every
                        , RRDSET_TYPE_LINE
                );
            }
            else
                rrdset_next(raid->st_mismatch_cnt);

            if(unlikely(!raid->rd_mismatch_cnt && !(raid->rd_mismatch_cnt = rrddim_find(raid->st_mismatch_cnt, "count"))))
                raid->rd_mismatch_cnt = rrddim_add(raid->st_mismatch_cnt, "count", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);

            rrddim_set_by_pointer(raid->st_mismatch_cnt, raid->rd_mismatch_cnt, raid->mismatch_cnt);

            rrdset_done(raid->st_mismatch_cnt);

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

            snprintfz(id, 50, "%s_operation", raid->name);

            if(unlikely(!raid->st_operation && !(raid->st_operation = rrdset_find_byname_localhost(id)))) {
                snprintfz(family, 50, "%s", raid->name);

                raid->st_operation = rrdset_create_localhost(
                        "mdstat"
                        , id
                        , NULL
                        , family
                        , "md.status"
                        , "Current Status"
                        , "percent"
                        , PLUGIN_PROC_NAME
                        , PLUGIN_PROC_MODULE_MDSTAT_NAME
                        , NETDATA_CHART_PRIO_MDSTAT_OPERATION + raid_idx * 10
                        , update_every
                        , RRDSET_TYPE_LINE
                );
            }
            else
                rrdset_next(raid->st_operation);

            if(unlikely(!raid->rd_check && !(raid->rd_check = rrddim_find(raid->st_operation, "check"))))
                raid->rd_check = rrddim_add(raid->st_operation, "check", NULL, 1, 100, RRD_ALGORITHM_ABSOLUTE);
            if(unlikely(!raid->rd_resync && !(raid->rd_resync = rrddim_find(raid->st_operation, "resync"))))
                raid->rd_resync = rrddim_add(raid->st_operation, "resync", NULL, 1, 100, RRD_ALGORITHM_ABSOLUTE);
            if(unlikely(!raid->rd_recovery && !(raid->rd_recovery = rrddim_find(raid->st_operation, "recovery"))))
                raid->rd_recovery = rrddim_add(raid->st_operation, "recovery", NULL, 1, 100, RRD_ALGORITHM_ABSOLUTE);
            if(unlikely(!raid->rd_reshape && !(raid->rd_reshape = rrddim_find(raid->st_operation, "reshape"))))
                raid->rd_reshape = rrddim_add(raid->st_operation, "reshape", NULL, 1, 100, RRD_ALGORITHM_ABSOLUTE);

            rrddim_set_by_pointer(raid->st_operation, raid->rd_check, raid->check);
            rrddim_set_by_pointer(raid->st_operation, raid->rd_resync, raid->resync);
            rrddim_set_by_pointer(raid->st_operation, raid->rd_recovery, raid->recovery);
            rrddim_set_by_pointer(raid->st_operation, raid->rd_reshape, raid->reshape);

            rrdset_done(raid->st_operation);

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

            snprintfz(id, 50, "%s_finish", raid->name);

            if(unlikely(!raid->st_finish && !(raid->st_finish = rrdset_find_byname_localhost(id)))) {
                snprintfz(family, 50, "%s", raid->name);

                raid->st_finish = rrdset_create_localhost(
                        "mdstat"
                        , id
                        , NULL
                        , family
                        , "md.rate"
                        , "Approximate Time Unit Finish"
                        , "seconds"
                        , PLUGIN_PROC_NAME
                        , PLUGIN_PROC_MODULE_MDSTAT_NAME
                        , NETDATA_CHART_PRIO_MDSTAT_FINISH + raid_idx * 10
                        , update_every
                        , RRDSET_TYPE_LINE
                );
            }
            else
                rrdset_next(raid->st_finish);

            if(unlikely(!raid->rd_finish_in && !(raid->rd_finish_in = rrddim_find(raid->st_finish, "finish_in"))))
                raid->rd_finish_in = rrddim_add(raid->st_finish, "finish_in", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);

            rrddim_set_by_pointer(raid->st_finish, raid->rd_finish_in, raid->finish_in);

            rrdset_done(raid->st_finish);

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

            snprintfz(id, 50, "%s_speed", raid->name);

            if(unlikely(!raid->st_speed && !(raid->st_speed = rrdset_find_byname_localhost(id)))) {
                snprintfz(family, 50, "%s", raid->name);

                raid->st_speed = rrdset_create_localhost(
                        "mdstat"
                        , id
                        , NULL
                        , family
                        , "md.rate"
                        , "Operation Speed"
                        , "KB/s"
                        , PLUGIN_PROC_NAME
                        , PLUGIN_PROC_MODULE_MDSTAT_NAME
                        , NETDATA_CHART_PRIO_MDSTAT_SPEED + raid_idx * 10
                        , update_every
                        , RRDSET_TYPE_LINE
                );
            }
            else
                rrdset_next(raid->st_speed);

            if(unlikely(!raid->rd_speed && !(raid->rd_speed = rrddim_find(raid->st_speed, "speed"))))
                raid->rd_speed = rrddim_add(raid->st_speed, "speed", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);

            rrddim_set_by_pointer(raid->st_speed, raid->rd_speed, raid->speed);

            rrdset_done(raid->st_speed);
        }
    }

    return 0;
}