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

void error(const char *msg)
{
    perror(msg);
    exit (EXIT_FAILURE);
}

struct mjpeg_header {
    unsigned short size;
    char reserved;
    char reserved2;
};

void save(char *img_data) {
    //TODO: dynamic filename
    FILE *file;
    file = fopen("/tmp/test.jpg","w+");

    if(file==NULL) {
        error("ERROR opening file");
    }

    fputs(img_data, file);

    fclose(file);
}

int main(int argc, char *argv[])
{

    int sock, n;
    unsigned short int port = 4321;

    struct sockaddr_in serv_addr;
    struct hostent *hostinfo;


    char request[] = {0x30,0x31,0x31,0x30,0x0a};
    char camera_address[] = "10.0.1.200";
    struct mjpeg_header header;

    sock = socket(AF_INET, SOCK_STREAM, 0);

    if (sock < 0) {
        error("ERROR opening socket");
    }

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(port);

    if (!(hostinfo = gethostbyname(camera_address))) {
        error("ERROR No host found");
    }

    serv_addr.sin_addr = *(struct in_addr*)hostinfo->h_addr;

    if (0 > connect(sock, (struct sockaddr *) &serv_addr, sizeof (serv_addr))) {
        error ("ERROR Connecting");
    }

    n = write(sock,request,strlen(request));

    if (n < 0) {
        error("ERROR writing to socket");
    }

    n = read(sock,&header,sizeof(header));

    if (n < 0) {
        error("ERROR reading from socket");
    }

    char image_data[header.size];

    bzero(image_data,header.size);

    n = read(sock,image_data,header.size);

    if (n < 0) {
        error("ERROR reading from socket");
    }

    close(sock);

    save(image_data);

    return 0;
}