#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#include "header.h"

#include <assert.h>

void send_packet(int transmit, struct packet const * const foo);
int read_packet(int recieve, struct packet* const foo);
void box_RX(int transmit, int recieve);
void box_TX(int transmit, int recieve);

unsigned char *buffer;
FILE* test;

struct packet foo;

int main()
{
	pid_t child;
	int TX[2];
	int RX[2];
	ssize_t rw_return;
	int pipe_return;

	foo.md5sum[16] = '\0';
	buffer = malloc(128);
	foo.payload = buffer;

	assert((pipe_return = pipe(TX)) == 0);
	assert((pipe_return = pipe(RX)) == 0);

	if((child = fork()) == -1)
	{
		return -1;
	} else if(child == 0)
	{
		unsigned char md5sum[16];
		/* child RX side*/
		assert(read_packet(RX[0], &foo) == 0);
		/*confirm MD5 */
		send_packet(TX[1], &foo);
		
		box_RX(TX[1], RX[0]);
	} else
	{
		fgets(buffer, 128, stdin);

		foo.pack_size = strlen(foo.payload)+20;
		MD5(foo.payload, foo.pack_size - 20, foo.md5sum);
		send_packet(RX[1], &foo);
		assert(read_packet(TX[0], &foo) == 0);
		printf("got %s\n", foo.payload);
		box_TX(RX[1], TX[0]);
		wait(NULL);
		/* parent TX side*/
	}
	return 0;
}

void send_packet(int transmit, struct packet const * const foo)
{
	static unsigned char md[16];
	int rw;
	rw = write(transmit, foo, 4);
	assert(rw == 4);
	rw = write(transmit, foo->payload, foo->pack_size- 20);
	assert(rw == foo->pack_size-20);
	MD5(foo->payload, foo->pack_size-20, md);
	rw = write(transmit, md, 16);
/*
	rw = write(transmit, foo->md5sum, 16);
*/
	assert(rw == 16);
}
int read_packet(int recieve, struct packet* const foo)
{
	static unsigned char md[16];
	int rw;
	if(foo->payload)
		free(foo->payload);
	rw = read(recieve, foo, 4);
	assert(rw == 4);
	foo->payload = malloc(foo->pack_size - 20);
	rw = read(recieve, foo->payload, foo->pack_size-20);
	assert(rw == foo->pack_size-20);
	rw = read(recieve, foo->md5sum, 16);
	assert(rw == 16);

	MD5(foo->payload, foo->pack_size-20, md);
	return memcmp(md, foo->md5sum, 16);
}

void box_RX(int transmit, int recieve)
{
}
void box_TX(int transmit, int recieve)
{
}