/* -*- 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_downstream.h>

#include <fluent-bit/flb_network.h>

#include <fluent-bit/flb_config.h>

#include "http_conn.h"

#include "opentelemetry.h"

#include "opentelemetry_prot.h"

#include "opentelemetry_config.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_opentelemetry_collect(struct flb_input_instance *ins,

                                    struct flb_config *config, void *in_context)

{

    struct flb_connection    *connection;

    struct http_conn         *conn;

    struct flb_opentelemetry *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 = opentelemetry_conn_add(connection, ctx);

    if (conn == NULL) {

        return -1;

    }

    return 0;

}

static int in_opentelemetry_init(struct flb_input_instance *ins,

                                 struct flb_config *config, void *data)

{

    unsigned short int        port;

    int                       ret;

    struct flb_opentelemetry *ctx;

    (void) data;

    /* Create context and basic conf */

    ctx = opentelemetry_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");

        opentelemetry_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 (ctx->enable_http2) {

        ret = flb_http_server_init(&ctx->http_server,

                                    HTTP_PROTOCOL_VERSION_AUTODETECT,

                                    (FLB_HTTP_SERVER_FLAG_KEEPALIVE | FLB_HTTP_SERVER_FLAG_AUTO_INFLATE),

                                    NULL,

                                    ins->host.listen,

                                    ins->host.port,

                                    ins->tls,

                                    ins->flags,

                                    &ins->net_setup,

                                    flb_input_event_loop_get(ins),

                                    ins->config,

                                    (void *) ctx);

        if (ret != 0) {

            flb_plg_error(ctx->ins,

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

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

            opentelemetry_config_destroy(ctx);

            return -1;

        }

        ret = flb_http_server_start(&ctx->http_server);

        if (ret != 0) {

            flb_plg_error(ctx->ins,

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

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

            opentelemetry_config_destroy(ctx);

            return -1;

        }

        flb_http_server_set_buffer_max_size(&ctx->http_server, ctx->buffer_max_size);

        ctx->http_server.request_callback = opentelemetry_prot_handle_ng;

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

    }

    else {

        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);

            opentelemetry_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_opentelemetry_collect,

                                            ctx->downstream->server_fd,

                                            config);

        if (ret == -1) {

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

            opentelemetry_config_destroy(ctx);

            return -1;

        }

        ctx->collector_id = ret;

    }

    flb_plg_info(ctx->ins, "listening on %s:%s", ctx->listen, ctx->tcp_port);

    if (ctx->successful_response_code != 200 &&

        ctx->successful_response_code != 201 &&

        ctx->successful_response_code != 204) {

        flb_plg_error(ctx->ins, "%d is not supported response code. Use default 201",

                      ctx->successful_response_code);

        ctx->successful_response_code = 201;

    }

    return 0;

}

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

{

    struct flb_opentelemetry *ctx;

    (void) config;

    ctx = data;

    if (ctx != NULL) {

        opentelemetry_config_destroy(ctx);

    }

    return 0;

}

/* Configuration properties map */

static struct flb_config_map config_map[] = {

    {

     FLB_CONFIG_MAP_BOOL, "http2", "true",

     0, FLB_TRUE, offsetof(struct flb_opentelemetry, enable_http2),

     "Enable HTTP/2 protocol support for the OpenTelemetry receiver"

    },

    {

     FLB_CONFIG_MAP_BOOL, "profiles_support", "false",

     0, FLB_TRUE, offsetof(struct flb_opentelemetry, profile_support_enabled),

     "This is an experimental feature whoses specification is not stable yet, " \

     "feel free to test it but please do not enable this in production " \

     "environments"

    },

    {

     FLB_CONFIG_MAP_BOOL, "encode_profiles_as_log", "true",

     0, FLB_TRUE, offsetof(struct flb_opentelemetry, encode_profiles_as_log),

     "Encode profiles received as text and ingest them in the logging pipeline"

    },

    {

     FLB_CONFIG_MAP_SIZE, "buffer_max_size", HTTP_BUFFER_MAX_SIZE,

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

     "Maximum size of the HTTP request buffer"

    },

    {

     FLB_CONFIG_MAP_SIZE, "buffer_chunk_size", HTTP_BUFFER_CHUNK_SIZE,

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

     "Size of each buffer chunk allocated for HTTP requests"

    },

    {

     FLB_CONFIG_MAP_STR, "tag_key", NULL,

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

     "Record accessor key to use for generating tags from incoming records"

    },

    {

     FLB_CONFIG_MAP_BOOL, "tag_from_uri", "true",

     0, FLB_TRUE, offsetof(struct flb_opentelemetry, tag_from_uri),

     "If true, tag will be created from uri. e.g. v1_metrics from /v1/metrics ."

    },

    {

     FLB_CONFIG_MAP_INT, "successful_response_code", "201",

     0, FLB_TRUE, offsetof(struct flb_opentelemetry, successful_response_code),

     "Set successful response code. 200, 201 and 204 are supported."

    },

    {

     FLB_CONFIG_MAP_BOOL, "raw_traces", "false",

     0, FLB_TRUE, offsetof(struct flb_opentelemetry, raw_traces),

     "Forward traces without processing"

    },

    {

     FLB_CONFIG_MAP_STR, "logs_metadata_key", "otlp",

     0, FLB_TRUE, offsetof(struct flb_opentelemetry, logs_metadata_key),

     "Key name to store OpenTelemetry logs metadata in the record"

    },

    {

     FLB_CONFIG_MAP_STR, "logs_body_key", NULL,

     0, FLB_TRUE, offsetof(struct flb_opentelemetry, logs_body_key),

     "Key to use for the logs body. If unset, body key-value pairs will be " \

     "used as the log record, and other types will be nested under a key."

    },

    /* EOF */

    {0}

};

/* Plugin reference */

struct flb_input_plugin in_opentelemetry_plugin = {

    .name         = "opentelemetry",

    .description  = "OpenTelemetry",

    .cb_init      = in_opentelemetry_init,

    .cb_pre_run   = NULL,

    .cb_collect   = in_opentelemetry_collect,

    .cb_flush_buf = NULL,

    .cb_pause     = NULL,

    .cb_resume    = NULL,

    .cb_exit      = in_opentelemetry_exit,

    .config_map   = config_map,

    .flags        = FLB_INPUT_NET_SERVER | FLB_IO_OPT_TLS

};