#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <math.h>
#include <windows.h>
#include <winsock.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <io.h>
#include <fstream>
#include <vector>
#define MAX_CONNECTION 100
#ifndef max
    #define max(a,b) ((a) < (b) ? (a) : (b))
#endif
typedef struct connection{
    char ipaddr[16];
    int port;
    int sd;
} connection;

static unsigned short SERVER_PORT = 4118;
int main(int argc, char* argv[])
{
    int maxfd =-1;
    fd_set   rset, allset;
    connection client[MAX_CONNECTION];

    int passiveSock; /* Main Server Socket */
    struct sockaddr_in servSock_in;
#ifdef WIN32
    WSADATA wsaData;
    WSAStartup(0x0101, &wsaData);
#endif
    int port;
    if (argc > 1)
        port = atoi(argv[1]);
    else
        port = SERVER_PORT;

    for(int i=0; i < MAX_CONNECTION ; i++)
        client[i].sd = -1;
    memset((char *)&servSock_in, 0, sizeof(servSock_in));
    servSock_in.sin_family = PF_INET;
    servSock_in.sin_addr.s_addr = htonl(INADDR_ANY);
    servSock_in.sin_port = htons((u_short)port);

    passiveSock = socket(PF_INET, SOCK_STREAM, 0);
    if (passiveSock < 0) {
        fprintf(stderr, "I am too tired... I failed to open gate...n");
        return -1;
    }
    if (bind(passiveSock, (struct sockaddr *)&servSock_in, sizeof(servSock_in)) < 0){
        fprintf(stderr, "I couldn't attach gate to port...n");
        return -1;
    }
    if (listen(passiveSock, 5) < 0) {
        fprintf(stderr, "I am not hearing anything...n");
        return -1;
    }

    FD_SET(passiveSock, &allset);
        maxfd = max(maxfd, passiveSock);

        struct sockaddr_in cliSock_in;
        int cliSockLen;
        int connectedSock;
        cliSockLen = sizeof(cliSock_in);
        printf("n Waiting for an incoming connection at port number %d", port);
        int bytesread = 0;
    for (;;)
    {
        //FD_ZERO(&allset);

        rset = allset;
        int nready = select(maxfd+1,&rset, NULL, NULL, NULL);
        if(FD_ISSET(passiveSock, &rset)){
            printf("In the first if");

            connectedSock = accept(passiveSock, (struct sockaddr *)&cliSock_in, &cliSockLen);
            /* if an error occurs while accepting */
            if (connectedSock == -1)    {
                printf("n Server: Accept error (errno = %d: %s)n", errno, strerror(errno));
                continue;
            }




            for (int i=0; i<MAX_CONNECTION; i++)
                if (client[i].sd < 0){
                    client[i].sd=connectedSock;
                    strcpy(client[i].ipaddr, inet_ntoa(cliSock_in.sin_addr));
                    client[i].port= ntohs(cliSock_in.sin_port);
                    printf("n Server: connection established with %s:%dn",
                        client[i].ipaddr, client[i].port);
                    break;
                }
            FD_SET(connectedSock, &allset);
            maxfd = max(maxfd, connectedSock);

        }

        else{
            for(int j = 0 ; j < MAX_CONNECTION; j++){
                connectedSock = client[j].sd;
                printf("connectedSock is %d", connectedSock);
                if(connectedSock < 0)
                    continue;
                if(FD_ISSET(client[j].sd, &rset)){
                    unsigned char buffer[66000];
                    int index = 0;
                    bytesread = recv(connectedSock, (char *)buffer, 66000, 0);
                    int  type;




                    type = (buffer[0] & 0xE0) >> 5;

                    if (type == 0)
                    {
                        char fname[100];
                        int i = 0;
                        int length = (buffer[i++] & 0x1F);
                        memcpy(&fname[0], &buffer[i], length);
                        fname[length] = '';
                        i += length;
                        int fs = 0;
                        fs += (buffer[i++] << 8) & 0xff00;
                        fs += buffer[i++];
                        char* filedata = (char*)malloc(fs*sizeof(char));
                        memcpy(&filedata[0], &buffer[i], fs);
                        filedata[fs] = '';
                        for (int i = 0; i < fs; i++)
                            printf("%c", filedata[i]);
                        printf("type=%d,length=%d,data=%s,fs=%d,filedata=%s", type, length, fname, fs, filedata);
                        std::ofstream of;
                        of.open(fname, std::ios::binary);
                        for (int i = 0; i < fs; i++)
                            of.write(filedata + i, 1);
                        of.close();
                        unsigned char rep;
                        int reptype = 0;
                        rep = (unsigned char)(reptype & 0x07);
                        send(connectedSock, (char*)(&rep), 1, 0);
                    }
                    else if (type == 1)
                    {
                        char fname[100];
                        int i = 0;
                        int length = (buffer[i++] & 0x1F);
                        memcpy(&fname[0], &buffer[i], length);
                        fname[length] = '';
                        i += length;
                        std::ifstream t;
                        int fs;
                        t.open(fname, std::ios::binary);
                        std::vector<char> vec((
                            std::istreambuf_iterator<char>(t)),
                            (std::istreambuf_iterator<char>()));// open input file
                        t.close();
                        fs = vec.size();
                        char* filedata = (char*)malloc(fs*sizeof(char));    // allocate memory for a buffer of appropriate dimension
                        filedata = &vec[0];
                        filedata[fs] = '';
                        i = 0;
                        unsigned char* repbuffer = (unsigned char*)malloc(3 + length + fs);
                        repbuffer[i] = (unsigned char)(type & 0x07);
                        repbuffer[i] = repbuffer[i] << 5;
                        repbuffer[i] = repbuffer[i] | (length & 0x0000003F);
                        i++;
                        memcpy(&repbuffer[i], fname, length);
                        i = i + length;
                        printf("sizeof fs=%d", sizeof(fs));
                        repbuffer[i++] = (unsigned char)((fs & 0xff00) >> 8);
                        repbuffer[i++] = (unsigned char)(fs & 0xff);
                        memcpy(&repbuffer[i], filedata, fs);
                        printf("sizeof buffer=%d", sizeof(repbuffer));
                        i = i + fs;
                    //  printf("the buffer contains %sn",&repbuffer[11]);
                        if (send(connectedSock, (char*)repbuffer, i, 0) == -1)
                        {
                            printf("A local error was detected while sending data! (errno = %d: %s)n", errno, strerror(errno));
                            return -1;
                        }
                    }
                    else if (type == 2)
                    {
                        char fname[100],nfname[100];
                        int i = 0;
                        int length = (buffer[i++] & 0x1F);
                        memcpy(&fname[0], &buffer[i], length);
                        fname[length] = '';
                        i += length;
                        int nlength = (buffer[i++] & 0x1F);
                        memcpy(&nfname[0], &buffer[i], nlength);
                        nfname[nlength] = '';
                        rename(fname,nfname);

                    }
                    else if (type == 3)
                    {
                        char rep[32];
                        strcpy(rep, "bye change get help put");
                        int length = strlen(rep);
                        unsigned char* repbuffer = (unsigned char*)malloc(1 + length);
                        int type = 6;
                        repbuffer[0] = (unsigned char)(type & 0x07);
                        repbuffer[0] = repbuffer[0] << 5;
                        repbuffer[0] = repbuffer[0] | (length & 0x0000003F);
                        memcpy(&repbuffer[1], rep, length);
                        if (send(connectedSock, (char*)repbuffer, length+1, 0) == -1)
                        {
                            perror("A local error was detected while sending data!!");
                            return -1;
                        }
                    }
                    else if (type == 4)
                    {
                        closesocket(connectedSock);
                    }

                    break;
                }
            }
        }
    }
    closesocket(passiveSock);
    WSACleanup();
    return 0;

}