/* -*- 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_random.h>

#include "in_elasticsearch.h"

#include "in_elasticsearch_config.h"

#include "in_elasticsearch_bulk_prot.h"

static void bytes_to_groupname(unsigned char *data, char *buf, size_t len) {

    int index;

    char charset[] = "0123456789"

                     "abcdefghijklmnopqrstuvwxyz"

                     "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    while (len-- > 0) {

        index = (int) data[len];

        index = index % (sizeof(charset) - 1);

        buf[len] = charset[index];

    }

}

static void bytes_to_nodename(unsigned char *data, char *buf, size_t len) {

    int index;

    char charset[] = "0123456789"

                     "abcdefghijklmnopqrstuvwxyz";

    while (len-- > 0) {

        index = (int) data[len];

        index = index % (sizeof(charset) - 1);

        buf[len] = charset[index];

    }

}

static int in_elasticsearch_bulk_init(struct flb_input_instance *ins,

                                      struct flb_config *config, void *data)

{

    int ret;

    struct flb_in_elasticsearch *ctx;

    unsigned char rand[16];

    struct flb_http_server_options http_server_options;

    (void) config;

    (void) data;

    /* Create context and basic conf */

    ctx = in_elasticsearch_config_create(ins);

    if (!ctx) {

        return -1;

    }

    /* Populate context with config map defaults and incoming properties */

    ret = flb_input_config_map_set(ins, (void *) ctx);

    if (ret == -1) {

        flb_plg_error(ctx->ins, "configuration error");

        in_elasticsearch_config_destroy(ctx);

        return -1;

    }

    /* Set the context */

    flb_input_set_context(ins, ctx);

    if (flb_random_bytes(rand, 16)) {

        flb_plg_error(ctx->ins, "cannot generate cluster name");

        in_elasticsearch_config_destroy(ctx);

        return -1;

    }

    bytes_to_groupname(rand, ctx->cluster_name, 16);

    if (flb_random_bytes(rand, 12)) {

        flb_plg_error(ctx->ins, "cannot generate node name");

        in_elasticsearch_config_destroy(ctx);

        return -1;

    }

    bytes_to_nodename(rand, ctx->node_name, 12);

    ret = flb_input_http_server_options_init(

            &http_server_options,

            ins,

            (FLB_HTTP_SERVER_FLAG_KEEPALIVE | FLB_HTTP_SERVER_FLAG_AUTO_INFLATE),

            in_elasticsearch_bulk_prot_handle_ng,

            ctx);

    if (ret == 0) {

        if (http_server_options.workers > 1) {

            ret = flb_input_ingress_enable(ins);

        }

    }

    if (ret == 0) {

        ret = flb_http_server_init_with_options(&ctx->http_server,

                                                &http_server_options);

        if (ret == 0) {

            ret = flb_http_server_start(&ctx->http_server);

        }

        if (ret == 0 && ctx->http_server.downstream != NULL) {

            ret = flb_input_downstream_set(ctx->http_server.downstream, ins);

        }

    }

    if (ret != 0) {

        flb_plg_error(ctx->ins,

                      "could not initialize http server on %s:%u. Aborting",

                      ins->host.listen, ins->host.port);

        in_elasticsearch_config_destroy(ctx);

        return -1;

    }

    flb_plg_info(ctx->ins, "listening on %s:%u with %i worker%s",

                 ins->host.listen,

                 ins->host.port,

                 ctx->http_server.workers,

                 ctx->http_server.workers == 1 ? "" : "s");

    return 0;

}

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

{

    struct flb_in_elasticsearch *ctx;

    (void) config;

    ctx = data;

    if (ctx != NULL) {

        in_elasticsearch_config_destroy(ctx);

    }

    return 0;

}

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

{

    struct flb_in_elasticsearch *ctx;

    (void) config;

    ctx = data;

    if (flb_http_server_pause(&ctx->http_server) != 0) {

        flb_plg_error(ctx->ins, "could not pause HTTP server");

        return -1;

    }

    return 0;

}

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

{

    struct flb_in_elasticsearch *ctx;

    (void) config;

    ctx = data;

    if (flb_http_server_resume(&ctx->http_server) != 0) {

        flb_plg_error(ctx->ins, "could not resume HTTP server");

        return -1;

    }

    return 0;

}

/* Configuration properties map */

static struct flb_config_map config_map[] = {

    {

     FLB_CONFIG_MAP_STR, "tag_key", NULL,

     0, FLB_TRUE, offsetof(struct flb_in_elasticsearch, tag_key),

     "Specify a key name for extracting as a tag"

    },

    {

     FLB_CONFIG_MAP_STR, "meta_key", "@meta",

     0, FLB_TRUE, offsetof(struct flb_in_elasticsearch, meta_key),

     "Specify a key name for meta information"

    },

    {

     FLB_CONFIG_MAP_STR, "hostname", "localhost",

     0, FLB_TRUE, offsetof(struct flb_in_elasticsearch, hostname),

     "Specify hostname or FQDN. This parameter is effective for sniffering node information."

    },

    {

     FLB_CONFIG_MAP_STR, "version", "8.0.0",

     0, FLB_TRUE, offsetof(struct flb_in_elasticsearch, es_version),

     "Specify returning Elasticsearch server version."

    },

    /* EOF */

    {0}

};

/* Plugin reference */

struct flb_input_plugin in_elasticsearch_plugin = {

    .name         = "elasticsearch",

    .description  = "HTTP Endpoints for Elasticsearch (Bulk API)",

    .cb_init      = in_elasticsearch_bulk_init,

    .cb_pre_run   = NULL,

    .cb_collect   = NULL,

    .cb_flush_buf = NULL,

    .cb_pause_checked = in_elasticsearch_bulk_pause,

    .cb_resume_checked = in_elasticsearch_bulk_resume,

    .cb_exit      = in_elasticsearch_bulk_exit,

    .config_map   = config_map,

    .flags        = FLB_INPUT_NET_SERVER | FLB_INPUT_HTTP_SERVER | FLB_IO_OPT_TLS

};