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

/*  Fluent Bit

 *  ==========

 *  Copyright (C) 2015-2023 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_network.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_conn.h"

/*

 * For a server event, the collection event means a new client have arrived, we

 * accept the connection and create a new TCP instance which will wait for

 * JSON map messages.

 */

static int in_elasticsearch_bulk_collect(struct flb_input_instance *ins,

                                         struct flb_config *config, void *in_context)

{

    struct flb_connection *connection;

    struct in_elasticsearch_bulk_conn *conn;

    struct flb_in_elasticsearch    *ctx;

    ctx = in_context;

    connection = flb_downstream_conn_get(ctx->downstream);

    if (connection == NULL) {

        flb_plg_error(ctx->ins, "could not accept new connection");

        return -1;

    }

    flb_plg_trace(ctx->ins, "new TCP connection arrived FD=%i",

                  connection->fd);

    conn = in_elasticsearch_bulk_conn_add(connection, ctx);

    if (conn == NULL) {

        flb_downstream_conn_release(connection);

        return -1;

    }

    return 0;

}

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)

{

    unsigned short int  port;

    int                 ret;

    struct flb_in_elasticsearch    *ctx;

    unsigned char rand[16];

    (void) data;

    /* Create context and basic conf */

    ctx = in_elasticsearch_config_create(ins);

    if (!ctx) {

        return -1;

    }

    ctx->collector_id = -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);

    port = (unsigned short int) strtoul(ctx->tcp_port, NULL, 10);

    if (flb_random_bytes(rand, 16)) {

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

        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");

        return -1;

    }

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

    ctx->downstream = flb_downstream_create(FLB_TRANSPORT_TCP,

                                            ins->flags,

                                            ctx->listen,

                                            port,

                                            ins->tls,

                                            config,

                                            &ins->net_setup);

    if (ctx->downstream == NULL) {

        flb_plg_error(ctx->ins,

                      "could not initialize downstream on %s:%s. Aborting",

                      ctx->listen, ctx->tcp_port);

        in_elasticsearch_config_destroy(ctx);

        return -1;

    }

    flb_input_downstream_set(ctx->downstream, ctx->ins);

    /* Collect upon data available on the standard input */

    ret = flb_input_set_collector_socket(ins,

                                         in_elasticsearch_bulk_collect,

                                         ctx->downstream->server_fd,

                                         config);

    if (ret == -1) {

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

        in_elasticsearch_config_destroy(ctx);

        return -1;

    }

    ctx->collector_id = ret;

    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;

}

/* Configuration properties map */

static struct flb_config_map config_map[] = {

    {

     FLB_CONFIG_MAP_SIZE, "buffer_max_size", HTTP_BUFFER_MAX_SIZE,

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

     "Set the maximum size of buffer"

    },

    {

     FLB_CONFIG_MAP_SIZE, "buffer_chunk_size", HTTP_BUFFER_CHUNK_SIZE,

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

     "Set the buffer chunk size"

    },

    {

     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."

    },

    /* 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   = in_elasticsearch_bulk_collect,

    .cb_flush_buf = NULL,

    .cb_pause     = NULL,

    .cb_resume    = NULL,

    .cb_exit      = in_elasticsearch_bulk_exit,

    .config_map   = config_map,

    .flags        = FLB_INPUT_NET_SERVER | FLB_IO_OPT_TLS

};