/* Bryce's Chat1 Program
 * Based on Beej's:
** server.c -- a stream socket server demo
** (Simplified to remove forking.)
*
*  Usage: supply the port to be used on the command line.
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define BACKLOG 10     // how many pending connections queue will hold


int main(int argc, char *argv[])
{
    int sockfd, new_fd;  // listen on sock_fd, new connection on new_fd
    struct sockaddr_in my_addr;    // my address information
    struct sockaddr_in their_addr; // connector's address information
    socklen_t sin_size;
    char buffer[128] = ""; /* Buffer for reading from client. */
    
    
    int yes=1;
    int port = 41000;

    if (argc < 2) {
        printf("Error: specify the port number on the command line.\n");
        exit(1);
    }

    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("socket");
        exit(1);
    }

    if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1) {
        perror("setsockopt");
        exit(1);
    }
    
    port = atoi(argv[1]);
    
    my_addr.sin_family = AF_INET;         // host byte order
    my_addr.sin_port = htons(port);     // short, network byte order
    my_addr.sin_addr.s_addr = INADDR_ANY; // automatically fill with my IP
    memset(my_addr.sin_zero, '\0', sizeof my_addr.sin_zero);

    if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof my_addr) == -1) {
        perror("bind");
        exit(1);
    }

    if (listen(sockfd, BACKLOG) == -1) {
        perror("listen");
        exit(1);
    }

    printf("Server serving. Press ^C to quit.\n");

    while(1) {  // main accept() loop
        sin_size = sizeof their_addr;
        if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size)) == -1) {
            perror("accept");
            continue;
        }
        printf("server: got connection from %s\n", \
            inet_ntoa(their_addr.sin_addr));
        
        if (send(new_fd, "connected\n", 11, 0) == -1)
            perror("send");
        if (recv(new_fd, buffer, 127, 0) == -1)
            perror("recv");
        printf("Got from client: %s\n",buffer);
        if (send(new_fd, buffer, strlen(buffer)+1, 0) == -1)
            perror("echo");
        printf("Echoed and disconnected.\n");
        close(new_fd);
    }

    return 0;
}