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

/*  Fluent Bit
 *  ==========
 *  Copyright (C) 2015-2022 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_output_plugin.h>
#include <fluent-bit/flb_pack.h>
#include <fluent-bit/flb_str.h>
#include <fluent-bit/flb_time.h>
#include <fluent-bit/flb_utils.h>
#include <fluent-bit/flb_pack.h>
#include <fluent-bit/flb_sds.h>
#include <fluent-bit/flb_config_map.h>
#include <fluent-bit/flb_log_event_decoder.h>
#include <msgpack.h>

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#include "tcp.h"
#include "tcp_conf.h"

static int cb_tcp_init(struct flb_output_instance *ins,
                       struct flb_config *config, void *data)
{
    struct flb_out_tcp *ctx = NULL;
    (void) data;

    ctx = flb_tcp_conf_create(ins, config);
    if (!ctx) {
        return -1;
    }

    /* Set the plugin context */
    flb_output_set_context(ins, ctx);

    return 0;
}

static int compose_payload(struct flb_out_tcp *ctx,
                           const char *tag, int tag_len,
                           const void *in_data, size_t in_size,
                           void **out_payload, size_t *out_size)
{
    int ret;
    flb_sds_t buf = NULL;
    flb_sds_t json = NULL;
    flb_sds_t str;
    msgpack_object map;
    struct flb_log_event_decoder log_decoder;
    struct flb_log_event log_event;

    /* raw message key by using a record accessor */
    if (ctx->ra_raw_message_key) {
        ret = flb_log_event_decoder_init(&log_decoder, (char *) in_data, in_size);

        if (ret != FLB_EVENT_DECODER_SUCCESS) {
            flb_plg_error(ctx->ins,
                          "Log event decoder initialization error : %d", ret);

            return -1;
        }

        buf = flb_sds_create_size(in_size);
        if (!buf) {
            flb_log_event_decoder_destroy(&log_decoder);
            return FLB_ERROR;
        }

        while ((ret = flb_log_event_decoder_next(
                        &log_decoder,
                        &log_event)) == FLB_EVENT_DECODER_SUCCESS) {

            map = *log_event.body;

            str = flb_ra_translate(ctx->ra_raw_message_key, (char *) tag, tag_len, map, NULL);
            if (!str) {
                continue;
            }

            ret = flb_sds_cat_safe(&buf, str, flb_sds_len(str));
            if (ret != 0) {
                flb_plg_error(ctx->ins, "failed to compose payload from '%s'", str);
            }
            flb_sds_destroy(str);

            /* append a new line */
            flb_sds_cat_safe(&buf, "\n", 1);
        }

        flb_log_event_decoder_destroy(&log_decoder);

        if (flb_sds_len(buf) == 0) {
            flb_sds_destroy(buf);
            return FLB_ERROR;
        }

        *out_payload = buf;
        *out_size = flb_sds_len(buf);
        return FLB_OK;
    }

    if (ctx->out_format == FLB_PACK_JSON_FORMAT_NONE) {
        /* nothing to do */
        *out_payload = (void*)in_data;
        *out_size = in_size;
        return FLB_OK;
    }

    json = flb_pack_msgpack_to_json_format(in_data,
                                           in_size,
                                           ctx->out_format,
                                           ctx->json_date_format,
                                           ctx->date_key);
    if (!json) {
        flb_plg_error(ctx->ins, "error formatting JSON payload");
        return FLB_ERROR;
    }
    *out_payload = (void*)json;
    *out_size = flb_sds_len(json);

    return FLB_OK;
}

static void cb_tcp_flush(struct flb_event_chunk *event_chunk,
                         struct flb_output_flush *out_flush,
                         struct flb_input_instance *i_ins,
                         void *out_context,
                         struct flb_config *config)
{
    int ret = FLB_ERROR;
    size_t bytes_sent;
    struct flb_upstream *u;
    struct flb_connection *u_conn;
    struct flb_out_tcp *ctx = out_context;
    void *out_payload = NULL;
    size_t out_size = 0;
    (void) i_ins;

    /* Get upstream context and connection */
    u = ctx->u;
    u_conn = flb_upstream_conn_get(u);
    if (!u_conn) {
        flb_plg_error(ctx->ins, "no upstream connections available to %s:%i",
                      u->tcp_host, u->tcp_port);
        FLB_OUTPUT_RETURN(FLB_RETRY);
    }

    ret = compose_payload(ctx,
                          event_chunk->tag, flb_sds_len(event_chunk->tag),
                          event_chunk->data, event_chunk->size,
                          &out_payload, &out_size);
    if (ret != FLB_OK) {
        flb_upstream_conn_release(u_conn);
        return FLB_OUTPUT_RETURN(ret);
    }

    if (ctx->ra_raw_message_key) {
        ret = flb_io_net_write(u_conn, out_payload, out_size, &bytes_sent);
        flb_sds_destroy(out_payload);
    }
    else if (ctx->out_format == FLB_PACK_JSON_FORMAT_NONE) {
        ret = flb_io_net_write(u_conn,
                               event_chunk->data, event_chunk->size,
                               &bytes_sent);
    }
    else {
        ret = flb_io_net_write(u_conn, out_payload, out_size, &bytes_sent);
        flb_sds_destroy(out_payload);
    }
    if (ret == -1) {
        flb_errno();
        flb_upstream_conn_release(u_conn);
        FLB_OUTPUT_RETURN(FLB_RETRY);
    }

    flb_upstream_conn_release(u_conn);
    FLB_OUTPUT_RETURN(FLB_OK);
}

static int cb_tcp_exit(void *data, struct flb_config *config)
{
    struct flb_out_tcp *ctx = data;

    flb_tcp_conf_destroy(ctx);
    return 0;
}

/* Configuration properties map */
static struct flb_config_map config_map[] = {
    {
     FLB_CONFIG_MAP_STR, "format", "msgpack",
     0, FLB_FALSE, 0,
     "Specify the payload format, supported formats: msgpack, json, "
     "json_lines or json_stream."
    },

    {
     FLB_CONFIG_MAP_STR, "json_date_format", "double",
     0, FLB_FALSE, 0,
     FBL_PACK_JSON_DATE_FORMAT_DESCRIPTION
    },

    {
     FLB_CONFIG_MAP_STR, "json_date_key", "date",
     0, FLB_TRUE, offsetof(struct flb_out_tcp, json_date_key),
     "Specify the name of the date field in output."
    },

    {
     FLB_CONFIG_MAP_STR, "raw_message_key", NULL,
     0, FLB_TRUE, offsetof(struct flb_out_tcp, raw_message_key),
     "use a raw message key for the message."
    },

    /* EOF */
    {0}
};

static int cb_tcp_format_test(struct flb_config *config,
                              struct flb_input_instance *ins,
                              void *plugin_context,
                              void *flush_ctx,
                              int event_type,
                              const char *tag, int tag_len,
                              const void *data, size_t bytes,
                              void **out_data, size_t *out_size)
{
    struct flb_out_tcp *ctx = plugin_context;
    int ret;

    ret = compose_payload(ctx, tag, tag_len, data, bytes, out_data, out_size);
    if (ret != FLB_OK) {
        flb_error("ret=%d", ret);
        return -1;
    }

    return 0;
}

/* Plugin reference */
struct flb_output_plugin out_tcp_plugin = {
    .name           = "tcp",
    .description    = "TCP Output",
    .cb_init        = cb_tcp_init,
    .cb_flush       = cb_tcp_flush,
    .cb_exit        = cb_tcp_exit,
    .config_map     = config_map,
    /* for testing */
    .test_formatter.callback = cb_tcp_format_test,

    .workers        = 2,
    .flags          = FLB_OUTPUT_NET | FLB_IO_OPT_TLS,
};