//#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG

#include <stdint.h>
#include <sys/socket.h>
#include <esp_log.h>
#include <string.h>
#include <freertos/ringbuf.h>

#include "socket_server.h"
#include "console_server.h"
#include "application.h"
#include "tasks.h"
#include "telnet_parser.h"
#include "console_ioimpl.h"

static const char *TAG = "console_srv";

Tcpd_t g_telnet_server = NULL;
TcpdClient_t telnetsrv_last_rx_client = NULL;

/**
 * Send a textual message to all the connected peers
 *
 * @param interface
 * @param packet
 * @param timeout
 * @return
 */
esp_err_t telnetsrv_send(TcpdClient_t client, const char *message, ssize_t len)
{
    if (!g_telnet_server) {
        ESP_LOGE(TAG, "server not inited");
        return ESP_FAIL;
    }

    if (len < 0) len = strlen(message);

    if (client) {
        tcpd_send(client, (const uint8_t *) message, len);
    } else {
        tcpd_broadcast(g_telnet_server, (const uint8_t *) message, len);
    }

    return ESP_OK;
}

/**
 * Handle received bytes
 *
 * @param client
 * @param buf
 * @param nbytes
 */
static void telnetsrv_handle(TcpdClient_t client, char *buf, int nbytes)
{
    void *ctx = tcpd_get_client_ctx(client);
    struct console_ioimpl *io = ctx;

    if (!ctx) {
        ESP_LOGE(TAG, "telnet rx with no ioctx!");
        return;
    }

    assert(CONSOLE_IOIMPL_MAGIC == io->__magic);

    int rv = xRingbufferSend(io->telnet.console_stdin_ringbuf, buf, (size_t) nbytes, pdMS_TO_TICKS(100));
    if (rv != pdPASS) {
        ESP_LOGE(TAG, "console ringbuf overflow");
    }
}

/**
 * Socket read handler
 */
esp_err_t read_fn(Tcpd_t serv, TcpdClient_t client, int sockfd)
{
    char buf[64];
    int nbytes = read(sockfd, buf, sizeof(buf));
    if (nbytes <= 0) return ESP_FAIL;

//    ESP_LOGI(TAG, "Rx %d bytes", nbytes);
    telnetsrv_handle(client, buf, nbytes);

    return ESP_OK;
}

static void print_motd(console_ctx_t *ctx)
{
    console_printf_ctx(ctx, COLOR_RESET, "\n"
                     "===================================================\n"
                     " ESP32 node "APP_NAME" "APP_VERSION " #" GIT_HASH "\n"
                     " Built " BUILD_TIMESTAMP "\n"
                     "\n"
                     " Run `ls` for a list of commands.\n"
                     "===================================================\n\n"
    );
    // show the initial prompt
    console_print(ctx->prompt);
}

/**
 * Socket open handler - send a MOTD
 */
static esp_err_t open_fn(Tcpd_t serv, TcpdClient_t client)
{
    vTaskDelay(pdMS_TO_TICKS(100));

    struct console_ioimpl *io = NULL;
    esp_err_t rv = console_start_tcp(&io, NULL, client);
    if (rv != ESP_OK) {
        return rv;
    }
    assert(io);

    // set telnet params, unless this is the injected stdin client
    if (tcpd_get_client_fd(client) != STDIN_FILENO) {
        telnet_send_will(&io->ctx, OPT_SUPPRESS_GO_AHEAD);
        telnet_send_will(&io->ctx, OPT_ECHO);
        telnet_send_dont(&io->ctx, OPT_ECHO);
    }

    return ESP_OK;
}

void console_print_motd(console_ctx_t *ctx)
{
    print_motd(ctx);
}

esp_err_t telnetsrv_start(uint16_t port)
{
    tcpd_config_t server_config = TCPD_INIT_DEFAULT();
    server_config.max_clients = 3;
    server_config.task_prio = TELNET_TASK_PRIO;
    server_config.task_stack = TELNET_TASK_STACK;
    server_config.task_name = "TelnetSrv";
    server_config.port = port;
    server_config.read_fn = read_fn;
    server_config.open_fn = open_fn;
    // close fn is not needed, console shuts down if the FD becomes invalid (read fails)

    ESP_ERROR_CHECK(tcpd_init(&server_config, &g_telnet_server));

    // this deadlocks now... XXX
//    cspemu_add_shutdown_handler(telnetsrv_kick_all);

    return ESP_OK;
}

void telnetsrv_kick_all(void)
{
    ESP_LOGI(TAG, "Kick all telnet clients");
    tcpd_kick_all(g_telnet_server, false); // don't kick injected clients
    ESP_LOGI(TAG, "Kicking done!");
}