/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*  Fluent Bit

 *  ==========

 *  Copyright (C) 2015-2026 The Fluent Bit Authors

 *

 *  Licensed under the Apache License, Version 2.0 (the "License");

 *  you may not use this file except in compliance with the License.

 *  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 *  Unless required by applicable law or agreed to in writing, software

 *  distributed under the License is distributed on an "AS IS" BASIS,

 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 *  See the License for the specific language governing permissions and

 *  limitations under the License.

 */

#include <fluent-bit/flb_input_plugin.h>

#include <fluent-bit/flb_config.h>

#include <fluent-bit/flb_metrics.h>

#include <fluent-bit/flb_metrics_exporter.h>

#include <fluent-bit/flb_jsmn.h>

#include <monkey/mk_core/mk_list.h>

#include "podman_metrics.h"

#include "podman_metrics_config.h"

#include "podman_metrics_data.h"

/*

 * Collect information about podman containers (ID and Name) from podman configuration

 * file (default is /var/lib/containers/storage/overlay-containers/containers.json).

 * Since flb_jsmn library show JSON as a tree, search for objects with parent 0 (objects

 * that are children to root array, and in them, search for ID and name (which is also

 * an array.

 */

static int collect_container_data(struct flb_in_metrics *ctx)

{

    /* Buffers for reading data from JSON */

    char *buffer;

    char name[CONTAINER_NAME_SIZE];

    char id[CONTAINER_ID_SIZE];

    char image_name[IMAGE_NAME_SIZE];

    char metadata[CONTAINER_METADATA_SIZE];

    char *metadata_token_start;

    char *metadata_token_stop;

    int metadata_token_size;

    int array_id;

    int r, i, j;

    size_t read_bytes = 0;

    int collected_containers = 0;

    int token_len;

    jsmn_parser p;

    jsmntok_t t[JSON_TOKENS];

    flb_utils_read_file(ctx->config, &buffer, &read_bytes);

    if (!read_bytes) {

        flb_plg_warn(ctx->ins, "Failed to open %s", ctx->config);

        return -1;

    }

    buffer[read_bytes] = 0;

    flb_plg_debug(ctx->ins, "Read %zu bytes", read_bytes);

    jsmn_init(&p);

    r = jsmn_parse(&p, buffer, strlen(buffer), t, sizeof(t) / sizeof(t[0]));

    if (r < 0) {

        flb_plg_warn(ctx->ins, "Failed to parse JSON %d: %s", r, buffer);

        free(buffer);

        return -1;

    }

    flb_plg_debug(ctx->ins, "Got %d nested tokens", t[0].size);

    if (r < 1 || t[0].type != JSMN_ARRAY) {

        flb_plg_warn(ctx->ins, "Expected array at the json root");

        free(buffer);

        return -1;

    }

    for (i=0; i<r; i++) {

        if (t[i].type == JSMN_STRING) {

            if (sizeof(JSON_FIELD_ID)-1 == t[i].end - t[i].start &&

                strncmp(buffer + t[i].start, JSON_FIELD_ID, t[i].end - t[i].start) == 0) {

                token_len = t[i + 1].end - t[i + 1].start;

                strncpy(id, buffer + t[i+1].start, t[i + 1].end - t[i + 1].start);

                id[token_len] = '\0';

                flb_plg_trace(ctx->ins, "Found id %s", id);

            }

            else if (sizeof(JSON_FIELD_NAMES)-1 == t[i].end - t[i].start &&

                     strncmp(buffer + t[i].start, JSON_FIELD_NAMES, t[i].end - t[i].start) == 0) {

                array_id = i + 1;

                if (t[array_id].type == JSMN_ARRAY) {

                    j = array_id + 1;

                    while (t[j].parent == array_id)

                    {

                        strncpy(name, buffer + t[j].start, t[j].end - t[j].start);

                        name[t[j].end - t[j].start] = '\0';

                        flb_plg_trace(ctx->ins, "Found name %s", name);

                        j++;

                    }

                }

            }

            else if (sizeof(JSON_FIELD_METADATA)-1 == t[i].end - t[i].start &&

                strncmp(buffer + t[i].start, JSON_FIELD_METADATA, t[i].end - t[i].start) == 0) {

                token_len = t[i + 1].end - t[i + 1].start;

                strncpy(metadata, buffer + t[i+1].start, t[i + 1].end - t[i + 1].start);

                metadata[token_len] = '\0';

                metadata_token_start = strstr(metadata, JSON_SUBFIELD_IMAGE_NAME);

                if (metadata_token_start) {

                    metadata_token_stop = strstr(metadata_token_start + JSON_SUBFIELD_SIZE_IMAGE_NAME+1, "\\\"");

                    metadata_token_size = metadata_token_stop - metadata_token_start - JSON_SUBFIELD_SIZE_IMAGE_NAME;

                    strncpy(image_name, metadata_token_start+JSON_SUBFIELD_SIZE_IMAGE_NAME, metadata_token_size);

                    image_name[metadata_token_size] = '\0';

                    flb_plg_trace(ctx->ins, "Found image name %s", image_name);

                    add_container_to_list(ctx, id, name, image_name);

                }

                else {

                    flb_plg_warn(ctx->ins, "Image name was not found for %s", id);

                    add_container_to_list(ctx, id, name, "unknown");

                }

                collected_containers++;

            }

        }

    }

    flb_plg_debug(ctx->ins, "Collected %d containers from podman config file", collected_containers);

    free(buffer);

    return collected_containers;

}

/*

 * Create structure instance based on previously found id, name and image name. Set all its values (like

 * memory or cpu to UINT64_MAX, in case it won't be found later. This function also adds this structure

 * to internal list, so it can be found by iteration later on.

 */

static int add_container_to_list(struct flb_in_metrics *ctx, flb_sds_t id, flb_sds_t name, flb_sds_t image_name)

{

    struct container *cnt;

    cnt = flb_malloc(sizeof(struct container));

    if (!cnt) {

        flb_errno();

        return -1;

    }

    cnt->id = flb_sds_create(id);

    cnt->name = flb_sds_create(name);

    cnt->image_name = flb_sds_create(image_name);

    cnt->memory_usage = UINT64_MAX;

    cnt->memory_max_usage = UINT64_MAX;

    cnt->memory_limit = UINT64_MAX;

    cnt->rss = UINT64_MAX;

    cnt->cpu_user = UINT64_MAX;

    cnt->cpu = UINT64_MAX;

    mk_list_init(&cnt->net_data);

    mk_list_add(&cnt->_head, &ctx->items);

    return 0;

}

/*

 * Iterate over container list and remove collected data

 */

static int destroy_container_list(struct flb_in_metrics *ctx)

{

    struct container *cnt;

    struct net_iface *iface;

    struct sysfs_path *pth;

    struct mk_list *head;

    struct mk_list *tmp;

    struct mk_list *inner_head;

    struct mk_list *inner_tmp;

    mk_list_foreach_safe(head, tmp, &ctx->items) {

        cnt = mk_list_entry(head, struct container, _head);

        flb_plg_debug(ctx->ins, "Destroying container data (id: %s, name: %s", cnt->id, cnt->name);

        flb_sds_destroy(cnt->id);

        flb_sds_destroy(cnt->name);

        flb_sds_destroy(cnt->image_name);

        mk_list_foreach_safe(inner_head, inner_tmp, &cnt->net_data) {

            iface = mk_list_entry(inner_head, struct net_iface, _head);

            flb_sds_destroy(iface->name);

            mk_list_del(&iface->_head);

            flb_free(iface);

        }

        mk_list_del(&cnt->_head);

        flb_free(cnt);

    }

    mk_list_foreach_safe(head, tmp, &ctx->sysfs_items) {

        pth = mk_list_entry(head, struct sysfs_path, _head);

        flb_plg_trace(ctx->ins, "Destroying sysfs data (name: %s", pth->path);

        flb_sds_destroy(pth->path);

        mk_list_del(&pth->_head);

        flb_free(pth);

    }

    return 0;

}

/*

 * Create counter for given metric name, using name, image name and value as counter labels. Counters

 * are created per counter name, so they are "shared" between multiple containers - counter

 * name remains the same, only labels like ID are changed.

 * This function creates counter only once per counter name - every next call only sets counter

 * value for specific labels.

 */

static int create_counter(struct flb_in_metrics *ctx, struct cmt_counter **counter, flb_sds_t id, flb_sds_t name, flb_sds_t image_name, flb_sds_t metric_prefix,

                          flb_sds_t *fields, flb_sds_t metric_name, flb_sds_t description, flb_sds_t interface, uint64_t value)

{

    flb_sds_t *labels;

    uint64_t fvalue = value;

    int label_count;

    if (value == UINT64_MAX) {

        flb_plg_debug(ctx->ins, "Ignoring invalid counter for %s, %s_%s_%s", name, COUNTER_PREFIX, metric_prefix, metric_name);

        return -1;

    }

    if (strcmp(metric_name, COUNTER_CPU) == 0 || strcmp(metric_name, COUNTER_CPU_USER) == 0) {

        fvalue = fvalue / 1000000000;

        flb_plg_trace(ctx->ins, "Converting %s from nanoseconds to seconds (%lu -> %lu)", metric_name, value, fvalue);

    }

    labels = (char *[]){id, name, image_name, interface};

    if (interface == NULL) {

        label_count = 3;

    }

    else {

        label_count = 4;

    }

    /* if counter was not yet created, it means that this function is called for the first time per counter type */

    if (*counter == NULL) {

        flb_plg_debug(ctx->ins, "Creating counter for %s, %s_%s_%s", name, COUNTER_PREFIX, metric_prefix, metric_name);

        *counter = cmt_counter_create(ctx->ins->cmt, COUNTER_PREFIX, metric_prefix, metric_name, description, label_count, fields);

    }

    /* Allow setting value that is not grater that current one (if, for example, memory usage stays exactly the same) */

    cmt_counter_allow_reset(*counter);

    flb_plg_debug(ctx->ins, "Set counter for %s, %s_%s_%s: %lu", name, COUNTER_PREFIX, metric_prefix, metric_name, fvalue);

    if (cmt_counter_set(*counter, cfl_time_now(), fvalue, label_count, labels) == -1) {

        flb_plg_warn(ctx->ins, "Failed to set counter for %s, %s_%s_%s", name, COUNTER_PREFIX, metric_prefix, metric_name);

        return -1;

    }

    return 0;

}

/*

 * Create gauge for given metric name, using name, image name and value as counter labels. Gauges

 * are created per counter name, so they are "shared" between multiple containers - counter

 * name remains the same, only labels like ID are changed.

 * This function creates gauge only once per counter name - every next call only sets gauge

 * value for specific labels.

 */

static int create_gauge(struct flb_in_metrics *ctx, struct cmt_gauge **gauge, flb_sds_t id, flb_sds_t name, flb_sds_t image_name, flb_sds_t metric_prefix,

                          flb_sds_t *fields, flb_sds_t metric_name, flb_sds_t description, flb_sds_t interface, uint64_t value)

{

    flb_sds_t *labels;

    int label_count;

    if (value == UINT64_MAX) {

        flb_plg_debug(ctx->ins, "Ignoring invalid gauge for %s, %s_%s_%s", name, COUNTER_PREFIX, metric_prefix, metric_name);

        return -1;

    }

    labels = (char *[]){id, name, image_name};

    label_count = 3;

    /* if gauge was not yet created, it means that this function is called for the first time per counter type */

    if (*gauge == NULL) {

        flb_plg_debug(ctx->ins, "Creating gauge for %s, %s_%s_%s", name, COUNTER_PREFIX, metric_prefix, metric_name);

        *gauge = cmt_gauge_create(ctx->ins->cmt, COUNTER_PREFIX, metric_prefix, metric_name, description, label_count, fields);

    }

    flb_plg_debug(ctx->ins, "Set gauge for %s, %s_%s_%s: %lu", name, COUNTER_PREFIX, metric_prefix, metric_name, value);

    if (cmt_gauge_set(*gauge, cfl_time_now(), value, label_count, labels) == -1) {

        flb_plg_warn(ctx->ins, "Failed to set gauge for %s, %s_%s_%s", name, COUNTER_PREFIX, metric_prefix, metric_name);

        return -1;

    }

    return 0;

}

/*

 * Call create_counter for every counter type defined in this plugin.

 *

 * Currently supported counters are:

 * - container_memory_usage_bytes

 * - container_memory_max_usage_bytes

 * - container_memory_rss

 * - container_spec_memory_limit_bytes

 * - container_cpu_user_seconds_total

 * - container_cpu_usage_seconds_total

 * - container_network_receive_bytes_total

 * - container_network_receive_errors_total

 * - container_network_transmit_bytes_total

 * - container_network_transmit_errors_total

 */

static int create_counters(struct flb_in_metrics *ctx)

{

    struct container *cnt;

    struct net_iface *iface;

    struct mk_list *head;

    struct mk_list *tmp;

    struct mk_list *inner_head;

    struct mk_list *inner_tmp;

    mk_list_foreach_safe(head, tmp, &ctx->items)

    {

        cnt = mk_list_entry(head, struct container, _head);

        create_counter(ctx, &ctx->c_memory_usage, cnt->id, cnt->name, cnt->image_name, COUNTER_MEMORY_PREFIX, FIELDS_METRIC, COUNTER_MEMORY_USAGE,

                       DESCRIPTION_MEMORY_USAGE, NULL, cnt->memory_usage);

        create_counter(ctx, &ctx->c_memory_max_usage, cnt->id, cnt->name, cnt->image_name, COUNTER_MEMORY_PREFIX, FIELDS_METRIC, COUNTER_MEMORY_MAX_USAGE,

                       DESCRIPTION_MEMORY_MAX_USAGE, NULL, cnt->memory_max_usage);

        create_counter(ctx, &ctx->c_memory_limit, cnt->id, cnt->name, cnt->image_name, COUNTER_SPEC_MEMORY_PREFIX, FIELDS_METRIC, COUNTER_MEMORY_LIMIT,

                       DESCRIPTION_MEMORY_LIMIT, NULL, cnt->memory_limit);

        create_gauge(ctx, &ctx->g_rss, cnt->id, cnt->name, cnt->image_name, COUNTER_MEMORY_PREFIX, FIELDS_METRIC, GAUGE_MEMORY_RSS,

                     DESCRIPTION_MEMORY_RSS, NULL, cnt->rss);

        create_counter(ctx, &ctx->c_cpu_user, cnt->id, cnt->name, cnt->image_name, COUNTER_CPU_PREFIX, FIELDS_METRIC, COUNTER_CPU_USER,

                       DESCRIPTION_CPU_USER, NULL, cnt->cpu_user);

        create_counter(ctx, &ctx->c_cpu, cnt->id, cnt->name, cnt->image_name, COUNTER_CPU_PREFIX, FIELDS_METRIC, COUNTER_CPU,

                       DESCRIPTION_CPU, NULL, cnt->cpu);

        mk_list_foreach_safe(inner_head, inner_tmp, &cnt->net_data)

        {

            iface = mk_list_entry(inner_head, struct net_iface, _head);

            create_counter(ctx, &ctx->rx_bytes, cnt->id, cnt->name, cnt->image_name, COUNTER_NETWORK_PREFIX, FIELDS_METRIC_WITH_IFACE, COUNTER_RX_BYTES,

                           DESCRIPTION_RX_BYTES, iface->name, iface->rx_bytes);

            create_counter(ctx, &ctx->rx_errors, cnt->id, cnt->name, cnt->image_name, COUNTER_NETWORK_PREFIX, FIELDS_METRIC_WITH_IFACE, COUNTER_RX_ERRORS,

                           DESCRIPTION_RX_ERRORS, iface->name, iface->rx_errors);

            create_counter(ctx, &ctx->tx_bytes, cnt->id, cnt->name, cnt->image_name, COUNTER_NETWORK_PREFIX, FIELDS_METRIC_WITH_IFACE, COUNTER_TX_BYTES,

                           DESCRIPTION_TX_BYTES, iface->name, iface->tx_bytes);

            create_counter(ctx, &ctx->tx_errors, cnt->id, cnt->name, cnt->image_name, COUNTER_NETWORK_PREFIX, FIELDS_METRIC_WITH_IFACE, COUNTER_TX_ERRORS,

                           DESCRIPTION_TX_ERRORS, iface->name, iface->tx_errors);

        }

    }

    return 0;

}

/* Main function. Destroy (optionally) previous data, gather container data and

 * create counters.

 */

static int scrape_metrics(struct flb_config *config, struct flb_in_metrics *ctx)

{

    uint64_t start_ts = cfl_time_now();

    flb_plg_debug(ctx->ins, "Starting to scrape podman metrics");

    if (destroy_container_list(ctx) == -1) {

        flb_plg_error(ctx->ins, "Could not destroy previous container data");

        return -1;

    }

    if (collect_container_data(ctx) == -1) {

        flb_plg_error(ctx->ins, "Could not collect container ids");

        return -1;

    }

    if (collect_sysfs_directories(ctx, ctx->sysfs_path) == -1)

    {

        flb_plg_error(ctx->ins, "Could not collect sysfs data");

        return -1;

    }

    if (ctx->cgroup_version == CGROUP_V1) {

        if (fill_counters_with_sysfs_data_v1(ctx) == -1) {

            flb_plg_error(ctx->ins, "Could not collect V1 sysfs data");

            return -1;

        }

    }

    else if (ctx->cgroup_version == CGROUP_V2) {

        if (fill_counters_with_sysfs_data_v2(ctx) == -1) {

            flb_plg_error(ctx->ins, "Could not collect V2 sysfs data");

            return -1;

        }

    }

    if (create_counters(ctx) == -1) {

        flb_plg_error(ctx->ins, "Could not create container counters");

        return -1;

    }

    if (flb_input_metrics_append(ctx->ins, NULL, 0, ctx->ins->cmt) == -1) {

        flb_plg_error(ctx->ins, "Could not append metrics");

        return -1;

    }

    flb_plg_info(ctx->ins, "Scraping metrics took %luns", cfl_time_now() - start_ts);

    return 0;

}

/*

 * Call scrape_metrics function every `scrape interval`.

 */

static int cb_metrics_collect_runtime(struct flb_input_instance *ins, struct flb_config *config, void *in_context)

{

    return scrape_metrics(config, in_context);

}

/*

 * Initialize plugin, setup config file path and (optionally) scrape container

 * data (if `scrape_at_start` is set).

 */

static int in_metrics_init(struct flb_input_instance *in, struct flb_config *config, void *data)

{

    struct flb_in_metrics *ctx;

    int coll_fd_runtime;

    ctx = flb_calloc(1, sizeof(struct flb_in_metrics));

    if (!ctx) {

        return -1;

    }

    ctx->ins = in;

    ctx->c_memory_usage = NULL;

    ctx->c_memory_max_usage = NULL;

    ctx->g_rss = NULL;

    ctx->c_memory_limit = NULL;

    ctx->c_cpu_user = NULL;

    ctx->c_cpu = NULL;

    ctx->rx_bytes = NULL;

    ctx->rx_errors = NULL;

    ctx->tx_bytes = NULL;

    ctx->tx_errors = NULL;

    if (flb_input_config_map_set(in, (void *) ctx) == -1) {

        flb_free(ctx);

        return -1;

    }

    flb_input_set_context(in, ctx);

    coll_fd_runtime = flb_input_set_collector_time(in, cb_metrics_collect_runtime, ctx->scrape_interval, 0, config);

    if (coll_fd_runtime == -1) {

        flb_plg_error(ctx->ins, "Could not set collector for podman metrics plugin");

        return -1;

    }

    ctx->coll_fd_runtime = coll_fd_runtime;

    if (ctx->podman_config_path) {

        flb_plg_info(ctx->ins, "Using config file %s", ctx->podman_config_path);

        ctx->config = flb_sds_create(ctx->podman_config_path);

    }

    else {

        flb_plg_info(ctx->ins, "Using default config file %s", PODMAN_CONFIG_DEFAULT_PATH);

        ctx->config = flb_sds_create(PODMAN_CONFIG_DEFAULT_PATH);

    }

    if (get_cgroup_version(ctx) == CGROUP_V2) {

        flb_plg_info(ctx->ins, "Detected cgroups v2");

        ctx->cgroup_version = CGROUP_V2;

    }

    else {

        flb_plg_info(ctx->ins, "Detected cgroups v1");

        ctx->cgroup_version = CGROUP_V1;

    }

    mk_list_init(&ctx->items);

    mk_list_init(&ctx->sysfs_items);

    if (ctx->scrape_interval >= 2 && ctx->scrape_on_start) {

        flb_plg_info(ctx->ins, "Generating podman metrics (initial scrape)");

        if (scrape_metrics(config, ctx) == -1) {

            flb_plg_error(ctx->ins, "Could not start collector for podman metrics plugin");

            flb_sds_destroy(ctx->config);

            destroy_container_list(ctx);

            flb_free(ctx);

            return -1;

        }

    }

    flb_plg_info(ctx->ins, "Generating podman metrics");

    return 0;

}

/*

 * Function called at plugin exit - destroy collected container data list.

 */

static int in_metrics_exit(void *data, struct flb_config *config)

{

    struct flb_in_metrics *ctx = data;

    if (!ctx) {

        return 0;

    }

    flb_sds_destroy(ctx->config);

    destroy_container_list(ctx);

    flb_free(ctx);

    return 0;

}

/*

 * Function called at plugin pause.

 */

static void in_metrics_pause(void *data, struct flb_config *config)

{

    struct flb_in_metrics *ctx = data;

    flb_input_collector_pause(ctx->coll_fd_runtime, ctx->ins);

}

/*

 * Function called at plugin resume.

 */

static void in_metrics_resume(void *data, struct flb_config *config)

{

    struct flb_in_metrics *ctx = data;

    flb_input_collector_resume(ctx->coll_fd_runtime, ctx->ins);

}