/*
 * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#include <stdio.h>
#include <string.h>
#include <esp_types.h>

#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "test_utils.h"
#include "unity.h"
#include "unity_fixture.h"

#include "soc/soc_caps.h"

#include "lwip/inet.h"
#include "lwip/netdb.h"
#include "lwip/sockets.h"
#include "lwip/tcpip.h"
#include "lwip/prot/iana.h"
#include "ping/ping_sock.h"
#include "dhcpserver/dhcpserver.h"
#include "dhcpserver/dhcpserver_options.h"
#include "esp_sntp.h"

#define ETH_PING_END_BIT BIT(1)
#define ETH_PING_DURATION_MS (5000)
#define ETH_PING_END_TIMEOUT_MS (ETH_PING_DURATION_MS * 2)
#define TEST_ICMP_DESTINATION_DOMAIN_NAME "127.0.0.1"


TEST_GROUP(lwip);

TEST_SETUP(lwip)
{
}

TEST_TEAR_DOWN(lwip)
{
}

static void test_on_ping_success(esp_ping_handle_t hdl, void *args)
{
    uint8_t ttl;
    uint16_t seqno;
    uint32_t elapsed_time, recv_len;
    ip_addr_t target_addr;
    esp_ping_get_profile(hdl, ESP_PING_PROF_SEQNO, &seqno, sizeof(seqno));
    esp_ping_get_profile(hdl, ESP_PING_PROF_TTL, &ttl, sizeof(ttl));
    esp_ping_get_profile(hdl, ESP_PING_PROF_IPADDR, &target_addr, sizeof(target_addr));
    esp_ping_get_profile(hdl, ESP_PING_PROF_SIZE, &recv_len, sizeof(recv_len));
    esp_ping_get_profile(hdl, ESP_PING_PROF_TIMEGAP, &elapsed_time, sizeof(elapsed_time));
    printf("%" PRId32 "bytes from %s icmp_seq=%d ttl=%d time=%" PRId32 " ms\n",
           recv_len, inet_ntoa(target_addr.u_addr.ip4), seqno, ttl, elapsed_time);
}

static void test_on_ping_timeout(esp_ping_handle_t hdl, void *args)
{
    uint16_t seqno;
    ip_addr_t target_addr;
    esp_ping_get_profile(hdl, ESP_PING_PROF_SEQNO, &seqno, sizeof(seqno));
    esp_ping_get_profile(hdl, ESP_PING_PROF_IPADDR, &target_addr, sizeof(target_addr));
    printf("From %s icmp_seq=%d timeout\n", inet_ntoa(target_addr.u_addr.ip4), seqno);
}

static void test_on_ping_end(esp_ping_handle_t hdl, void *args)
{
    EventGroupHandle_t eth_event_group = (EventGroupHandle_t)args;
    uint32_t transmitted;
    uint32_t received;
    uint32_t total_time_ms;

    esp_ping_get_profile(hdl, ESP_PING_PROF_REQUEST, &transmitted, sizeof(transmitted));
    esp_ping_get_profile(hdl, ESP_PING_PROF_REPLY, &received, sizeof(received));
    esp_ping_get_profile(hdl, ESP_PING_PROF_DURATION, &total_time_ms, sizeof(total_time_ms));
    printf("%" PRId32 " packets transmitted, %" PRId32 " received, time %" PRId32 "ms\n", transmitted, received, total_time_ms);
    if (transmitted == received) {
        xEventGroupSetBits(eth_event_group, ETH_PING_END_BIT);
    }
}

TEST(lwip, localhost_ping_test)
{
    EventBits_t bits;
    EventGroupHandle_t eth_event_group = xEventGroupCreate();
    TEST_ASSERT(eth_event_group != NULL);
    test_case_uses_tcpip();

    // Parse IP address: Destination is a localhost address, so we don't need any interface (esp-netif/driver)
    ip_addr_t target_addr;
    struct addrinfo hint;
    struct addrinfo *res = NULL;
    memset(&hint, 0, sizeof(hint));
    memset(&target_addr, 0, sizeof(target_addr));
    /* convert URL to IP */
    TEST_ASSERT(getaddrinfo(TEST_ICMP_DESTINATION_DOMAIN_NAME, NULL, &hint, &res) == 0);
    struct in_addr addr4 = ((struct sockaddr_in *)(res->ai_addr))->sin_addr;
    inet_addr_to_ip4addr(ip_2_ip4(&target_addr), &addr4);
    freeaddrinfo(res);

    esp_ping_config_t ping_config = ESP_PING_DEFAULT_CONFIG();
    ping_config.timeout_ms = 2000;
    ping_config.target_addr = target_addr;
    ping_config.count = 0; // ping in infinite mode
    /* set callback functions */
    esp_ping_callbacks_t cbs;
    cbs.on_ping_success = test_on_ping_success;
    cbs.on_ping_timeout = test_on_ping_timeout;
    cbs.on_ping_end = test_on_ping_end;
    cbs.cb_args = eth_event_group;

    esp_ping_handle_t ping;
    TEST_ESP_OK(esp_ping_new_session(&ping_config, &cbs, &ping));
    /* start ping */
    TEST_ESP_OK(esp_ping_start(ping));
    /* ping for a while */
    vTaskDelay(pdMS_TO_TICKS(ETH_PING_DURATION_MS));
    /* stop ping */
    TEST_ESP_OK(esp_ping_stop(ping));
    /* wait for end of ping */
    bits = xEventGroupWaitBits(eth_event_group, ETH_PING_END_BIT, true, true, pdMS_TO_TICKS(ETH_PING_END_TIMEOUT_MS));
    TEST_ASSERT((bits & ETH_PING_END_BIT) == ETH_PING_END_BIT);
    /* restart ping */
    TEST_ESP_OK(esp_ping_start(ping));
    vTaskDelay(pdMS_TO_TICKS(ETH_PING_DURATION_MS));
    TEST_ESP_OK(esp_ping_stop(ping));
    bits = xEventGroupWaitBits(eth_event_group, ETH_PING_END_BIT, true, true, pdMS_TO_TICKS(ETH_PING_END_TIMEOUT_MS));
    TEST_ASSERT((bits & ETH_PING_END_BIT) == ETH_PING_END_BIT);
    /* de-initialize ping process */
    TEST_ESP_OK(esp_ping_delete_session(ping));

    vEventGroupDelete(eth_event_group);
}

TEST(lwip, dhcp_server_init_deinit)
{
    dhcps_t *dhcps = dhcps_new();
    TEST_ASSERT_NOT_NULL(dhcps);
    ip4_addr_t ip = { .addr = IPADDR_ANY };
    TEST_ASSERT(dhcps_start(dhcps, NULL, ip) == ERR_ARG);
    TEST_ASSERT(dhcps_stop(dhcps, NULL) == ERR_ARG);
    dhcps_delete(dhcps);
}

struct dhcps_api {
    EventGroupHandle_t event;
    ip4_addr_t netmask;
    ip4_addr_t ip;
    err_t ret_start;
    err_t ret_stop;
};

static void dhcps_test_net_classes_api(void* ctx)
{
    struct netif *netif;
    struct dhcps_api *api = ctx;

    NETIF_FOREACH(netif) {
        if (netif->name[0] == 'l' && netif->name[1] == 'o') {
            break;
        }
    }
    TEST_ASSERT_NOT_NULL(netif);

    dhcps_t *dhcps = dhcps_new();
    dhcps_set_option_info(dhcps, SUBNET_MASK, (void*)&api->netmask, sizeof(api->netmask));
    api->ret_start = dhcps_start(dhcps, netif, api->ip);
    api->ret_stop = dhcps_stop(dhcps, netif);
    dhcps_delete(dhcps);
    xEventGroupSetBits(api->event, 1);
}

static void dhcps_test_net_classes(uint32_t ip, uint32_t mask, bool pass)
{

    struct dhcps_api api = {
            .ret_start = ERR_IF,
            .ret_stop = ERR_IF,
            .ip = {.addr = PP_HTONL(ip)},
            .netmask = {.addr = PP_HTONL(mask)},
            .event = xEventGroupCreate()
    };

    tcpip_callback(dhcps_test_net_classes_api, &api);
    xEventGroupWaitBits(api.event, 1, true, true, pdMS_TO_TICKS(5000));
    vEventGroupDelete(api.event);
    err_t ret_start_expected = pass ? ERR_OK : ERR_ARG;
    TEST_ASSERT(api.ret_start == ret_start_expected);
    TEST_ASSERT(api.ret_stop == ERR_OK);

}

TEST(lwip, dhcp_server_start_stop_localhost)
{
    test_case_uses_tcpip();

    // Class A: IP: 127.0.0.1, Mask: 255.0.0.0
    dhcps_test_net_classes(0x7f000001, 0xFF000000, true);

    // Class B: IP: 128.1.1.1, Mask: 255.255.0.0
    dhcps_test_net_classes(0x80010101, 0xFFFF0000, true);

    // Class C: IP: 192.168.1.1, Mask: 255.255.255.0
    dhcps_test_net_classes(0xC0A80101, 0xFFFFFF00, true);


    // Class A: IP: 127.0.0.1, with inaccurate Mask: 255.248.255.0
    // expect dhcps_start() to fail
    dhcps_test_net_classes(0x7f000001, 0xFFF8FF00, false);

}


int test_sntp_server_create(void)
{
    struct sockaddr_in dest_addr_ip4;
    int sock = -1;
    dest_addr_ip4.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
    dest_addr_ip4.sin_family = AF_INET;
    dest_addr_ip4.sin_port = htons(LWIP_IANA_PORT_SNTP);
    sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
    TEST_ASSERT_GREATER_OR_EQUAL(0, sock);
    int reuse_en = 1;
    TEST_ASSERT_GREATER_OR_EQUAL(0, setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &reuse_en, sizeof(reuse_en)));
    TEST_ASSERT_GREATER_OR_EQUAL(0, bind(sock, (struct sockaddr*) &dest_addr_ip4, sizeof(dest_addr_ip4)));
    return sock;
}

bool test_sntp_server_reply_with_time(int sock, int year, bool msb_flag)
{
    struct sntp_timestamp {
        uint32_t seconds;
        uint32_t fraction;
    };
    const int SNTP_MSG_LEN = 48;
    const int SNTP_MODE_CLIENT = 0x03;
    const int SNTP_MODE_SERVER = 0x04;
    const int SNTP_MODE_MASK = 0x07;
    const int SNTP_OFFSET_STRATUM = 1;

    char rx_buffer[SNTP_MSG_LEN];
    struct sockaddr_storage source_addr;
    socklen_t socklen = sizeof(source_addr);

    int len = recvfrom(sock, rx_buffer, SNTP_MSG_LEN, 0, (struct sockaddr *)&source_addr, &socklen);
    if (len == SNTP_MSG_LEN && source_addr.ss_family == PF_INET && (SNTP_MODE_MASK & rx_buffer[0]) == SNTP_MODE_CLIENT) {
        // modify the client's request to act as a server's response with the injected *xmit* timestamp
        rx_buffer[0] &= ~SNTP_MODE_CLIENT;
        rx_buffer[0] |= SNTP_MODE_SERVER;
        rx_buffer[SNTP_OFFSET_STRATUM] = 0x1;
        // set the desired timestamp
        struct sntp_timestamp *timestamp = (struct sntp_timestamp *)(rx_buffer + SNTP_MSG_LEN - sizeof(struct sntp_timestamp)); // xmit is the last timestamp in the datagram
        int64_t seconds_since_1900 = (365*24*60*60 /* seconds per year */ + 24*60*60/4 /* ~ seconds per leap year */ )*(year-1900);
        // apply the MSB convention (set: 1968-2036, cleared: 2036-2104)
        timestamp->seconds = htonl( (msb_flag ? 0x80000000 : 0) | (0xFFFFFFFF & seconds_since_1900) );
        len = sendto(sock, rx_buffer, SNTP_MSG_LEN, 0, (struct sockaddr *)&source_addr, sizeof(source_addr));
        if (len == SNTP_MSG_LEN) {
            return true;
        }
    }
    return false;
}

void test_sntp_timestamps(int year, bool msb_flag)
{
    int sock = test_sntp_server_create();

    // init and start the SNTP
    esp_sntp_setoperatingmode(SNTP_OPMODE_POLL);
    esp_sntp_setservername(0, "127.0.0.1");
    esp_sntp_init();
    // wait until time sync
    int retry = 0;
    while (sntp_get_sync_status() == SNTP_SYNC_STATUS_RESET) {
        TEST_ASSERT_TRUE(test_sntp_server_reply_with_time(sock, year, msb_flag)); // post the SNTP server's reply
        retry++;
        TEST_ASSERT_LESS_THAN(3, retry);
    }

    // check time and assert the year
    time_t now;
    struct tm timeinfo;
    time(&now);
    localtime_r(&now, &timeinfo);
    TEST_ASSERT_EQUAL(year, 1900 + timeinfo.tm_year);

    // close the SNTP and the fake server
    esp_sntp_stop();
    close(sock);
}

TEST(lwip, sntp_client_time_2015)
{
    test_case_uses_tcpip();
    test_sntp_timestamps(2015, true); // NTP timestamp MSB is set for time before 2036
}

TEST(lwip, sntp_client_time_2048)
{
    test_case_uses_tcpip();
    test_sntp_timestamps(2048, false); // NTP timestamp MSB is cleared for time after 2036
}

TEST_GROUP_RUNNER(lwip)
{
    RUN_TEST_CASE(lwip, localhost_ping_test)
    RUN_TEST_CASE(lwip, dhcp_server_init_deinit)
    RUN_TEST_CASE(lwip, dhcp_server_start_stop_localhost)
    RUN_TEST_CASE(lwip, sntp_client_time_2015)
    RUN_TEST_CASE(lwip, sntp_client_time_2048)
}

void app_main(void)
{
    UNITY_MAIN(lwip);
}