#include <sys/socket.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <netdb.h>
#include <netinet/in.h>
#include <ctype.h>
#include <iostream.h>
#include <iomanip.h>
#include <string.h>
#include <signal.h>

#include "multimandel.h"

int in_sock,recv_sock,send_sock;
struct cmd_msg msgbuf;
struct data_msg *data;
size_t data_size;

double x_1,x_2,dx,*xval,*xsq;
int width,numcolors,maxit;
int *modtab;

void fini(int)
 {
   shutdown(in_sock,2); close(in_sock);
   shutdown(recv_sock,2); close(recv_sock);
   shutdown(send_sock,2); close(send_sock);
   signal(SIGINT,SIG_DFL); raise(SIGINT);
 }

void sorry(const char *s) { perror(s); fini(0); }

ostream & operator << (ostream &o, const struct in_addr &adr)
 {
   unsigned char c[4];
   memcpy(c,&adr,4);
   return o << (int)c[0]<<'.'<<(int)c[1]<<'.'<<(int)c[2]<<'.'<<(int)c[3];
 }

int x_recv(int fd, void *data, int size)
 {
   char *P=(char *)data;
   int left=size,bytes;
   do
    {
      if ((bytes=recv(fd,P,left,0))<0) return 0;
      P+=bytes;
      left-=bytes;
    }
   while (left>0);
   return size;
 }

int one_point(double x0, double y0, double x2, double y2)
 {
   double x=x0,y=y0;
   int it=0,cmp=msgbuf.depth;
   if (x2+y2>=4.0) return 0;
   for (;;)
    {
      if (++it==cmp) return it;
      y+=(y*=x)+y0;
      x=x2-y2+x0;
      if ((x2=x*x)+(y2=y*y)>=4.0) return it;
    }
 }

void one_line()
 {
   unsigned char *P=data->it;
   double y2=msgbuf.y*msgbuf.y,*xP=xval,*x2P=xsq;

   for (int i=0;i<width;++i)
      *P++=modtab[one_point(*xP++,msgbuf.y,*x2P++,y2)];
 }

int main()
 {
   signal(SIGPIPE,fini);
   signal(SIGINT,fini);

   in_sock=socket(AF_INET,SOCK_STREAM,0);
   if (in_sock<0) sorry("socket");

   struct sockaddr_in s_in;
   memset(&s_in,0,sizeof(s_in));
   s_in.sin_family=AF_INET;
   s_in.sin_addr.s_addr=INADDR_ANY;
   s_in.sin_port=htons(SLAVEPORT);

   // cout << "binding ..." << endl;
   if (bind(in_sock,(struct sockaddr*)&s_in,sizeof(s_in))<0) sorry("bind");

   // cout << "listening ..." << endl;
   if (listen(in_sock,10)<0) sorry("listen");

   struct sockaddr_in incoming;
   int addrlen=sizeof(struct sockaddr_in);
   // cout << "accepting ..." << endl;
   recv_sock=accept(in_sock,(struct sockaddr*)&incoming,&addrlen);
   if (recv_sock<0) sorry("accept");

   // cout << "accepted from " << incoming.sin_addr << endl;

   send_sock=socket(AF_INET,SOCK_STREAM,0);
   if (send_sock<0) sorry("socket");

   incoming.sin_port=htons(MASTERPORT);
   if (connect(send_sock,(struct sockaddr *)&incoming,sizeof(incoming))<0)
      sorry("connect");

   for (;;)
    {
      // cout << "receiving..." << endl;
      if (x_recv(recv_sock,&msgbuf,sizeof(msgbuf))==0) sorry("recv");
      // cout << "received " << msgbuf.num << endl;

      switch (msgbuf.command)
       {
         case 'q':
            fini(0);
         case 's':
            width=msgbuf.width; numcolors=msgbuf.line; maxit=msgbuf.depth;
            x_1=msgbuf.x1; x_2=msgbuf.x2; dx=(x_2-x_1)/width;
            xval=new double[width]; xsq=new double[width];
            for (int i=0;i<width;++i) { xval[i]=x_1+i*dx; xsq[i]=xval[i]*xval[i]; }
            modtab=new int[maxit+1];
             for (int i=0,j=1;i<maxit;++i)
              {
                modtab[i]=j;
                if (++j>=numcolors) j=1;
              }
            data_size=sizeof(data_msg)+sizeof(unsigned char[width]);
            data=(data_msg*)new char[data_size];
            data->num=msgbuf.num;
            // cout << "I am slave number " << msgbuf.num << endl;
            if (send(send_sock,data,data_size,0)<0) sorry("send");
            // cout << "hello sent" << endl;
            break;
         case 'c':
            // cout << "compute line " << msgbuf.line << ' ' << msgbuf.y << endl;
            one_line();
            data->line=msgbuf.line;
            if (send(send_sock,data,data_size,0)<0) sorry("send");
            // cout << "sent line " << msgbuf.line << " to master" << endl;
            break;
         default:
            cerr << "unknown command " << msgbuf.command << endl;
       }
    }
 }