/*
 * Copyright (c) 2019, ARM Limited, All Rights Reserved
 * SPDX-License-Identifier: Apache-2.0
 *
 * 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 "mbed.h"
#include "EventFlags.h"
#include "greentea-client/test_env.h"
#include "nidd_tests.h"
#include "unity/unity.h"
#include "utest.h"

using namespace utest::v1;

namespace {
const int SIGNAL_SIGIO_RX = 0x1;
const int SIGNAL_SIGIO_TX = 0x2;
const int SIGIO_TIMEOUT = 1000; //[ms]
const int RETRIES = 2;

const double EXPECTED_LOSS_RATIO = 0.0;
const double TOLERATED_LOSS_RATIO = 0.5;

CellularNonIPSocket *sock;
EventFlags signals;

const int NIDD_BUFF_SIZE = 100;
char rx_buffer[NIDD_BUFF_SIZE] = {0};
char tx_buffer[NIDD_BUFF_SIZE] = {0};

const int PKTS = 11;
const int pkt_sizes[PKTS] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, NIDD_BUFF_SIZE};
Timer tc_exec_time;
int time_allotted;
}

static void _sigio_handler()
{
    signals.set(SIGNAL_SIGIO_RX | SIGNAL_SIGIO_TX);
}

void NIDDSOCKET_ECHOTEST_NONBLOCK()
{
    tc_exec_time.start();
    time_allotted = split2half_rmng_nidd_test_time(); // [s]

    sock = new CellularNonIPSocket();
    if (sock == NULL) {
        TEST_FAIL_MESSAGE("NIDDSocket not created");
        return;
    }
    TEST_ASSERT_EQUAL(NSAPI_ERROR_OK, sock->open(CellularContext::get_default_nonip_instance()));
    sock->set_blocking(false);
    sock->sigio(callback(_sigio_handler));

    int sent;
    int packets_sent = 0;
    int packets_recv = 0;
    int recvd = 0;
    for (unsigned int s_idx = 0; s_idx < sizeof(pkt_sizes) / sizeof(*pkt_sizes); ++s_idx) {
        int pkt_s = pkt_sizes[s_idx];
        int packets_sent_prev = packets_sent;
        for (int retry_cnt = 0; retry_cnt <= RETRIES; retry_cnt++) {
            fill_tx_buffer_ascii(tx_buffer, pkt_s);
            tx_buffer[pkt_s] = '\0';
            sent = sock->send(tx_buffer, pkt_s);
            if (sent == pkt_s) {
                packets_sent++;
            } else if (sent == NSAPI_ERROR_WOULD_BLOCK) {
                if (tc_exec_time.read() >= time_allotted ||
                        signals.wait_all(SIGNAL_SIGIO_TX, SIGIO_TIMEOUT) == osFlagsErrorTimeout) {
                    continue;
                }
                --retry_cnt;
            } else {
                tr_warn("send %d, error %d\n", s_idx, sent);
                continue;
            }

            for (int retry_recv = 0; retry_recv <= RETRIES; retry_recv++) {
                recvd = sock->recv(rx_buffer, pkt_s);
                rx_buffer[recvd] = '\0';
                if (recvd == NSAPI_ERROR_WOULD_BLOCK) {
                    if (tc_exec_time.read() >= time_allotted) {
                        tr_warn("recv timeout (%d)", time_allotted);
                        break;
                    }
                    signals.wait_all(SIGNAL_SIGIO_RX, SIGIO_TIMEOUT);
                    --retry_recv;
                    continue;
                } else if (recvd < 0) {
                    tr_warn("sock.recvfrom error %d\n", recvd);
                    TEST_FAIL();
                    break;
                } else if (recvd == pkt_s) {
                    break;
                }
            }

            if (recvd == pkt_s) {
                break;
            }
        }
        // Make sure that at least one packet of every size was sent.
        TEST_ASSERT_TRUE(packets_sent > packets_sent_prev);
        if (recvd != pkt_s) {
            tr_warn("send/recv size %d/%d", pkt_s, recvd);
        } else if (memcmp(tx_buffer, rx_buffer, pkt_s) != 0) {
            tr_warn("send/recv payload mismatch");
        } else {
            packets_recv++;
        }
    }

    // Packet loss up to 30% tolerated
    if (packets_sent > 0) {
        double loss_ratio = 1 - ((double)packets_recv / (double)packets_sent);
        tr_info("Packets sent: %d, packets received %d, loss ratio %.2lf", packets_sent, packets_recv, loss_ratio);
        TEST_ASSERT_DOUBLE_WITHIN(TOLERATED_LOSS_RATIO, EXPECTED_LOSS_RATIO, loss_ratio);
    }
    TEST_ASSERT_EQUAL(NSAPI_ERROR_OK, sock->close());
    delete sock;
    tc_exec_time.stop();
}