Prog

#include <stdbool.h>     // use booleans in C
#include <stdlib.h>      // use common functions
#include <stdio.h>       // use input/output functions
#include <string.h>      // use string functions
#include <unistd.h>      // use POSIX functions

#include <sys/socket.h>  // use socket function
#include <netinet/in.h>  // use internet address datatypes
#include <arpa/inet.h>   // use inet_ntoa function
#include <netdb.h>       // use network database functions

/** Print field represented by given character array.
    The array must contains 9 chars ('O', 'X' or ' ')
    ordered row-wise from top left to bottom right. */
void printField(char* field)
{
    printf("+---+---+---+\n");
    for (int row = 0; row < 3; row++) {
        for (int col = 0; col < 3; col++) {
            printf("| %c ", field[row*3+col]);
        }
        printf("|\n+---+---+---+\n");
    }
}

/** Simple client application for Tic-Tac-Toe game using UDP.
    Hostname and port number of server are passed as arguments.
    By default, the server is assumed at localhost, port 5001.
*/
int main(int argc, char* argv[])
{
    // Read parameters
    if (argc != 3) {
        printf("Usage: TicTacToeClient [<hostname>] [<port>]\n\n");
    }
    char* hostname = argc > 1 ? argv[1] : "localhost";
    int port = argc > 2 ? atoi(argv[2]) : 5001;

    /** -- Setup connection -- */
    //Set server port
    struct hostent* serverInfo = gethostbyname(hostname);
    if (serverInfo == NULL) {
        printf("Failed to get info for host '%s'!\n", hostname);
        return -1;
    }

    // Create UDP/IP socket
    int sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock < 0) {
        printf("Failed to create socket!\n");
        return -1;
    }


    // Set address and port of server
    struct sockaddr_in serverAddr;
    serverAddr.sin_family = serverInfo->h_addrtype;
    serverAddr.sin_port = htons(port);
    memcpy(&serverAddr.sin_addr.s_addr, serverInfo->h_addr, serverInfo->h_length);
    unsigned int addrLen = sizeof(serverAddr);

    printf("Expecting server at %s:%d\n\n",
           inet_ntoa(serverAddr.sin_addr), ntohs(serverAddr.sin_port));


    /** -- Main game -- */

    bool running = true;
    char message[16];
    char command[6];
    char field[9];
    memset(field, ' ', 9);
    printField(field);
    while (running)
    {
        // Read row and column from user
        int row = 0, col = 0;
        printf("Select row and column (1-3): ");
        scanf("%d %d", &row, &col);
        while (getchar() != '\n') {}  // discard remaining input
        if (row < 1 || row > 3 || col < 1 || col > 3) {
            printf("Invalid row or column!\n");
            continue;
        }

        // Update field
        int idx = (row-1)*3 + col-1;
        if (field[idx] != ' ') {
            printf("This field is already occupied!\n");
            continue;
        }
        field[idx] = 'X';
        printField(field);

        // TODO : Send message to server, receive and process response
        memset(message, 0, 16);
        strncpy(command, message, 6);
        strncpy(field, message+6, 9);
        message[16] = '\0';

        // Send message to server
        if (sendto(sock, message, 16, 0, (struct sockaddr*)&serverAddr, addrLen) < 0) {
            printf("Failed to send message to server!\n");
            running = false;
            continue;
        } else {
            printf("Sent message to server: \"%s\"\n", message);
        }

        // Receive response from server
        printf("Waiting for response...\n");
        memset(message, 0, 16);
        if (recvfrom(sock, message, 1024, 0, (struct sockaddr*)&serverAddr, &addrLen) < 0) {
            printf("Failed to receive response from server!\n");
            running = false;
            continue;
        }


        memcpy(command, message, 5);
        command[5] = '\0';
        memcpy(field, message + 6, 9);

        // Check message and field and respond
        if (strcmp(command, "FIELD") == 0) {
            printField(field);
            continue;
        }
        else if (strcmp(command, "FWINX") == 0) {
            printf("Der Spieler hat gewonnen!");
            running = false;
        }
        else if(strcmp(command, "FWINO") == 0) {
            printf("Der Computer hat gewonnen!");
            running = false;
        }
        else if(strcmp(command, "FDRAW") == 0) {
            printf("Das Spiel endete unentschieden.");
            running = false;
        }
        else if(strcmp(command, "ERROR") == 0) {
            printf("Zug ungültig.");
            running = false;
        }
    }

    close(sock);
    return 0;
}