#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <uuid/uuid.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netdb.h>
#include <errno.h>

#include <logger.h>
#include <mongoose.h>
#include <handlers.h>
#include <helpers.h>
#include <mpack.h>
#include <enums.h>

void
handler_discovery(struct mg_connection *c, int ev, void *ev_data)
{
    (void)ev_data;
    if(ev == MG_EV_RECV)
    {
        uint16_t discovery_answer_port;
        char ip_buf[32];
        mg_conn_addr_to_str(c, ip_buf, sizeof(ip_buf), MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_REMOTE);

        if(c->recv_mbuf.len != sizeof(discovery_answer_port))
        {
            LOGGER_ERR("received invalid discovery from %s\n", ip_buf);
            return;
        }
        discovery_answer_port = *((uint16_t*)c->recv_mbuf.buf);

        LOGGER_INFO("received discovery from %s:%d\n", ip_buf, discovery_answer_port);

        if(discovery_answer_port == 0)
        {
            LOGGER_ERR("invalid port received\n");
            return;
        }

        char* payload;
        size_t payload_size;
        mpack_writer_t writer;
        mpack_writer_init_growable(&writer, &payload, &payload_size);

        mpack_start_map(&writer, 4);
        mpack_write_uint(&writer, DISCOVERY_MAPPING_ID);
        mpack_write_bin(&writer, (char*)global_controller->uid, sizeof(uuid_t));
        mpack_write_uint(&writer, DISCOVERY_MAPPING_COMMAND_PORT);
        mpack_write_u16(&writer, global_controller->command_port);
        mpack_write_uint(&writer, DISCOVERY_MAPPING_RELAY_COUNT);
        mpack_write_u8(&writer, global_config.relay_count);
        mpack_write_uint(&writer, DISCOVERY_MAPPING_NAME);
        mpack_write_cstr(&writer, global_controller->name);
        mpack_finish_map(&writer);

        // finish writing
        if(mpack_writer_destroy(&writer) != mpack_ok)
        {
            LOGGER_ERR("error writing discovery answer payload\n");
            return;

        }

        size_t bytes_transferred;
        int fd_answer = helper_connect_tcp_server(ip_buf, discovery_answer_port);
        if(fd_answer == -1)
        {
            LOGGER_ERR("error during connecting\n");
            free(payload);
            return;
        }

        if((bytes_transferred = send(fd_answer, &payload_size, sizeof(payload_size), 0)) <= 0)
        {
            LOGGER_ERR("error during sending\n");
            free(payload);
            close(fd_answer);
            return;
        }
        if((bytes_transferred = send(fd_answer, payload, payload_size, 0)) <= 0)
        {
            LOGGER_ERR("error during sending\n");
            free(payload);
            close(fd_answer);
            return;
        }

        free(payload);
    }
}