#include "bus.h"
#include "timer.h"


void file_produce(file_t* f, char x)
{
	f->buffer[f->t]=x;
	f->t=(f->t+1)%1024;
}

char file_consume(file_t* f)
{
	char x;
	while(f->t==f->q) micro_sleep(10);
	x=f->buffer[f->q];
	f->q=(f->q+1)%1024;
	return x;
}

int file_size(file_t* f)
{
	return (f->t>=f->q)?f->t-f->q:1024-f->q+f->t;
}

void file_init(file_t* file)
{
	file->t=file->q=0;
}


void bus_init_recv(bus_t* bus, int d, int  clk, int ack)
{
	bus->data=d;
	bus->clk=clk;
	bus->ack=ack;
	bus->ismaster=0;
	file_init(&bus->buffer);
	if (wiringPiSetup() == -1)
	{
		perror("Unable to setup wiring pi\n");
    exit (1);
  }else printf("WiringPi successfully setup\n");
}


void bus_init_send(bus_t* bus, int d, int  clk, int ack)
{
	bus->data=d;
	bus->clk=clk;
	bus->ack=ack;
	bus->ismaster=1;
	file_init(&bus->buffer);
}


void _bus_write(bus_t* bus, char x)
{
	int i;
	unsigned long ref= time_micros();
	if(!bus->ismaster) return;
	for(i=0; i<8; i++)
	{
		while(read_pin(bus->ack)) micro_sleep(10);
		write_pin(bus->data, (x&(1<<i))?1:0);
		write_pin(bus->clk, 1);
		while(!read_pin(bus->ack)) micro_sleep(10);
		write_pin(bus->clk, 0);
	}
}

char _bus_read(bus_t* bus)
{
	int x=0, i, j=0;
	if(bus->ismaster) return -1;
	for(i=0; i<8; i++)
	{
		write_pin(bus->ack, 0);
		while(!read_pin(bus->clk)) micro_sleep(10);
		j=read_pin(bus->data);
		x+=j<<i;
		write_pin(bus->ack, 1);
		micro_sleep(50);
		write_pin(bus->ack, 0);
	}
	return x;
}

void* bus_send_thread(void* _bus)
{
	bus_t* bus = (bus_t*)_bus;
	if(!bus->ismaster) return NULL;
	while(1)
	{
		while(!file_size(&bus->buffer)) micro_sleep(10); 
		_bus_write(bus, file_consume(&bus->buffer));
	}
	return NULL;
}

void* bus_recv_thread(void* _bus)
{
	bus_t* bus = (bus_t*)_bus;
	if(bus->ismaster) return NULL;
	while(1)
	{
		file_produce(&bus->buffer, _bus_read(bus));
	}
	return NULL;
}

void bus_write(bus_t* bus, const void* x, int length)
{
	const uint8_t *iter=(const uint8_t*)x;
	int i;
	if(!bus->ismaster) return;
	
	for(i=0; i<length; i++)
		file_produce(&bus->buffer, iter[i]);
}

void bus_read(bus_t* bus, void* x, int length)
{
	uint8_t *iter=(uint8_t*)x;
	int i;
	if(bus->ismaster) return;
	for(i=0; i<length; i++)
	  iter[i]=file_consume(&bus->buffer);
}


void bus_write_sync(bus_t* bus, const void* x, int length)
{
	const uint8_t *iter=(const uint8_t*)x;
	int i;
	if(!bus->ismaster) return;
	
	for(i=0; i<length; i++)
		_bus_write(bus, iter[i]);
	
}