#include "tcp_server.h"

#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "lwip/api.h"
#include "lwip/ip_addr.h"

#include "app_runtime.h"
#include "config.h"
#include "debug_log.h"
#include "route_msg.h"

#define TCP_SERVER_ACCEPT_TIMEOUT_MS 100
#define TCP_SERVER_STOP_POLL_MS      50u

static BaseType_t tcp_server_stop_requested(void)
{
    return (app_network_task_stop_requested() != pdFALSE) ? pdTRUE : pdFALSE;
}

static BaseType_t tcp_server_delay_with_stop(uint32_t delay_ms)
{
    uint32_t remaining_ms = delay_ms;

    while (remaining_ms > 0u) {
        uint32_t slice_ms = (remaining_ms > TCP_SERVER_STOP_POLL_MS) ? TCP_SERVER_STOP_POLL_MS : remaining_ms;

        if (tcp_server_stop_requested() != pdFALSE) {
            return pdFALSE;
        }

        vTaskDelay(pdMS_TO_TICKS(slice_ms));
        remaining_ms -= slice_ms;
    }

    return (tcp_server_stop_requested() == pdFALSE) ? pdTRUE : pdFALSE;
}

static err_t tcp_server_worker(struct netconn *conn, uint8_t link_index)
{
    struct netbuf *buf;
    const device_config_t *cfg = config_get();
    uint8_t uart_endpoint = config_uart_index_to_endpoint(cfg->links[link_index].uart);
    uint8_t src_endpoint = config_link_index_to_endpoint(link_index);
    err_t err;
    route_msg_t *tx_msg;
    route_send_result_t route_result;

    netconn_set_recvtimeout(conn, 10);

    for (;;) {
        if (tcp_server_stop_requested() != pdFALSE) {
            return ERR_CLSD;
        }

        err = netconn_recv(conn, &buf);
        if (err == ERR_OK) {
            do {
                void *data;
                uint16_t len;
                netbuf_data(buf, &data, &len);
                route_result = route_send(xTcpRxQueue,
                                          src_endpoint,
                                          uart_endpoint,
                                          (link_index == CONFIG_LINK_S1) ? ROUTE_CONN_S1 : ROUTE_CONN_S2,
                                          (const uint8_t *)data,
                                          len,
                                          pdMS_TO_TICKS(10));
                if (route_result != ROUTE_SEND_OK) {
                    debug_log_printf("[SRV] idx=%u rx-route-fail rc=%s len=%u\r\n",
                                     (unsigned int)link_index,
                                     route_send_result_to_str(route_result),
                                     (unsigned int)len);
                    netbuf_delete(buf);
                    return ERR_CLSD;
                }
            } while (netbuf_next(buf) >= 0);
            netbuf_delete(buf);
        } else if (err == ERR_TIMEOUT) {
            if (tcp_server_stop_requested() != pdFALSE) {
                return ERR_CLSD;
            }
        } else {
            break;
        }

        while (xQueueReceive(xLinkTxQueues[link_index], &tx_msg, 0) == pdPASS) {
            if (tcp_server_stop_requested() != pdFALSE) {
                route_msg_free(tx_msg);
                return ERR_CLSD;
            }
            err = netconn_write(conn, tx_msg->data, tx_msg->len, NETCONN_COPY);
            route_msg_free(tx_msg);
            if (err != ERR_OK) {
                return err;
            }
        }
    }

    return err;
}

static void tcp_server_task(uint8_t link_index)
{
    const device_config_t *cfg;
    struct netconn *listener;
    struct netconn *newconn;

    netconn_thread_init();

    for (;;) {
        if (tcp_server_stop_requested() != pdFALSE) {
            break;
        }

        while (g_netif_ready == pdFALSE) {
            if (tcp_server_stop_requested() != pdFALSE) {
                goto exit_task;
            }
            vTaskDelay(pdMS_TO_TICKS(100));
        }

        cfg = config_get();
        if (cfg->links[link_index].enabled == 0u) {
            if (tcp_server_stop_requested() != pdFALSE) {
                break;
            }
            if (tcp_server_delay_with_stop(500u) == pdFALSE) {
                break;
            }
            continue;
        }

        listener = netconn_new(NETCONN_TCP);
        if (listener == NULL) {
            if (tcp_server_delay_with_stop(500u) == pdFALSE) {
                break;
            }
            continue;
        }

        netconn_set_recvtimeout(listener, TCP_SERVER_ACCEPT_TIMEOUT_MS);

        if (netconn_bind(listener, IP_ADDR_ANY, cfg->links[link_index].local_port) != ERR_OK ||
            netconn_listen(listener) != ERR_OK) {
            netconn_delete(listener);
            if (tcp_server_delay_with_stop(500u) == pdFALSE) {
                break;
            }
            continue;
        }

        for (;;) {
            if (tcp_server_stop_requested() != pdFALSE || cfg->links[link_index].enabled == 0u) {
                break;
            }
            if (netconn_accept(listener, &newconn) == ERR_OK) {
                tcp_server_worker(newconn, link_index);
                netconn_close(newconn);
                netconn_delete(newconn);
            }
        }

        netconn_close(listener);
        netconn_delete(listener);
    }

exit_task:
    netconn_thread_cleanup();
    app_on_network_task_exit(xTaskGetCurrentTaskHandle());
    vTaskDelete(NULL);
}

void TcpSrvTask_S1(void *argument)
{
    (void)argument;
    tcp_server_task(CONFIG_LINK_S1);
}

void TcpSrvTask_S2(void *argument)
{
    (void)argument;
    tcp_server_task(CONFIG_LINK_S2);
}