/* io.c */
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netdb.h>

#include "SolarSim.h"

void
read_initial( AState state, const char *filename ) {
	int i;
	double rx, ry, rz, vx, vy, vz, mass;

	FILE *f = fopen(filename, "rt");
	if( !f ) {
		state->particles = 0;
		return;
	}

	fscanf( f, "%d\n", &state->particles );
	state->masses = malloc( state->particles * sizeof(real) );
	state->positions = malloc( state->particles * sizeof(vector) );
	state->velocities = malloc( state->particles * sizeof(vector) );
	state->accelerations = malloc( state->particles * sizeof(vector) );
	
	for( i = 0; i < state->particles; i++ ) {
		fscanf( f, "%lf %lf %lf %lf %lf %lf %lf\n", &rx, &ry, &rz, &vx, &vy, &vz, &mass );
		state->masses[i] = mass;
		v_init(&state->positions[i],(real)rx,(real)ry,(real)rz);
		v_init(&state->velocities[i],(real)vx,(real)vy,(real)vz);
	}

	fclose(f);
}

int
connect_to_server( char *servername, int portno, int PROTOCOL ){
	return connect_to_server_tcp(servername, portno);
}

int
connect_to_server_tcp( char* servername, int portno ){
	struct sockaddr_in serv_addr;
	struct hostent *server;
	int server_sockfd;

	server_sockfd = socket( AF_INET, SOCK_STREAM, 0 );
	if ( server_sockfd < 0 ) {
        	printf ( "ERROR opening socket" );
		return -1;
	}
    
	server = gethostbyname( servername );
	if (server == NULL) {
        	fprintf( stderr, "ERROR, no such host\n" );
		return -1;
	}
    
	memset( (char *) &serv_addr, 0, sizeof(serv_addr) );
	serv_addr.sin_family = AF_INET;
	memcpy( (char *)&serv_addr.sin_addr.s_addr, (char *)server->h_addr, server->h_length );
	serv_addr.sin_port = htons( portno );
    
	if ( connect( server_sockfd, (struct sockaddr*) &serv_addr, sizeof( serv_addr ) ) < 0 ) {
        	printf( "ERROR connecting" );
		return -1;
	}

	return server_sockfd;
}


int
connect_to_server_udp( char* servername, int portno ){
	struct sockaddr_in serv_addr, cli_addr;
	struct hostent *server;
	int server_sockfd, n;

	server_sockfd = socket( AF_INET, SOCK_DGRAM, 0 );
	if ( server_sockfd < 0 ) {
        	printf ( "ERROR opening socket" );
		return -1;
	}
    
	server = gethostbyname( servername );
	if (server == NULL) {
        	fprintf( stderr, "ERROR, no such host\n" );
		return -1;
	}
    
	memset( (char *) &serv_addr, 0, sizeof(serv_addr) );
	serv_addr.sin_family = AF_INET;
	memcpy( (char *)&serv_addr.sin_addr.s_addr, (char *)server->h_addr, server->h_length );
	serv_addr.sin_port = htons( portno );

	memset( (char *) &cli_addr, 0, sizeof(cli_addr) );
	cli_addr.sin_family = AF_INET;
	cli_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	cli_addr.sin_port = htons(0);

	n = bind(server_sockfd, (struct sockaddr *) &cli_addr, sizeof(cli_addr));
   	if( n < 0 ) {
		fprintf(stderr, "%d: cannot bind port\n", portno);
      		return -1;
	}

	return server_sockfd;
}

void
send_state( int sock, AState state ) {
	send( sock, &state->particles, sizeof(int), 0 );
	send( sock, state->masses, state->particles*sizeof(real), 0 );
	send( sock, state->positions, state->particles*sizeof(vector), 0 );
	send( sock, state->velocities, state->particles*sizeof(vector), 0 );
}

void
write_state( int fd, AState state ) {
	write( fd, &state->particles, sizeof(int) );
	write( fd, state->masses, state->particles*sizeof(real) );
	write( fd, state->positions, state->particles*sizeof(vector) );
	write( fd, state->velocities, state->particles*sizeof(vector) );
}