#include<iostream>
#include<cstring>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<unistd.h>
#include<pthread.h>

void Usage(std::string proc)
{
    std::cout << "\n\rUsage: " << proc << "serverip serverport\n" << std::endl;
}

struct ThreadData
{
    struct sockaddr_in server;
    int sockfd;
};

void *recv_message(void *args)
{
    ThreadData *td = static_cast<ThreadData*>(args);
    char buffer[1024];
    while(true)
    {
        struct sockaddr_in temp;
        socklen_t len = sizeof(temp);
        ssize_t s = recvfrom(td->sockfd, buffer, 1023, 0, (struct sockaddr*)&temp, &len);
        if (s > 0)
        {
            buffer[s] = 0;
            // std::cout << buffer << std::endl;
            printf("%s\n",buffer);
            fflush(stdout);
            bzero(buffer, sizeof(buffer));
            // std::cout << ntohs(temp.sin_addr.s_addr) << std::endl;
        }
    }
}

void *send_message(void *args)
{
    ThreadData *td = static_cast<ThreadData*>(args);
    std::string message;
    while(true)
    {
        // std::cout << "Please Enter@ ";
        getline(std::cin, message);
        sendto(td->sockfd, message.c_str(), message.size(), 0, (struct sockaddr*)&td->server, sizeof(td->server));
    }
}

int main(int argc, char *argv[])
{
    if(argc != 3)
    {
        Usage(argv[0]);
        exit(0);
    }
    std::string serverip = argv[1];
    uint16_t serverport = std::stoi(argv[2]);

    ThreadData td;

    bzero(&td.server, sizeof(td.server));
    td.server.sin_family = AF_INET;
    td.server.sin_port = htons(serverport);
    td.server.sin_addr.s_addr = inet_addr(serverip.c_str());
    
    td.sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if(td.sockfd < 0)
    {
        std::cout << "socket create error" << std::endl;
        return 1;
    }

    pthread_t recvr, sender;
    pthread_create(&recvr, nullptr, send_message, &td);
    pthread_create(&sender, nullptr, recv_message, &td);

    //客户端不需要显式bind,由os动态选择
    //在首次发送数据的时候，os给我们bind

    pthread_join(recvr, nullptr);
    pthread_join(sender, nullptr);
    close(td.sockfd);
    return 0;
}