#include "pdp6.h"
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h> 
#include <poll.h>

/* TODO? implement motor delays */

char *ptr_ident = PTR_IDENT;
char *ptp_ident = PTP_IDENT;

static void
recalc_ptp_req(Ptp *ptp)
{
	setreq(ptp->bus, PTP, ptp->flag ? ptp->pia : 0);
}

static void
recalc_ptr_req(Ptr *ptr)
{
	setreq(ptr->bus, PTR, ptr->flag ? ptr->pia : 0);
}

/* We have to punch after DATAO SET has happened. But BUSY is set by
 * DATAO CLEAR. So we use waitdatao to record when SET has happened */

static void
ptpcycle(void *p)
{
	Ptp *ptp;
	uchar c;

	ptp = p;
	if(ptp->busy && ptp->waitdatao){
		if(ptp->fd >= 0){
			if(ptp->b)
				c = (ptp->ptp & 077) | 0200;
			else
				c = ptp->ptp;
			write(ptp->fd, &c, 1);
		}
		ptp->busy = 0;
		ptp->flag = 1;
		recalc_ptp_req(ptp);
	}
}

static void
ptrcycle(void *p)
{
	Ptr *ptr;
	uchar c;

	ptr = p;
	if(!ptr->busy || !ptr->motor_on)
		return;

	// PTR CLR
	ptr->sr = 0;
	ptr->ptr = 0;
next:
	if(ptr->fd >= 0 && hasinput(ptr->fd)){
		if(read(ptr->fd, &c, 1) != 1)
			c = 0;
	}else
		c = 0;
	if(!ptr->b || c & 0200){
		// PTR STROBE
		ptr->sr <<= 1;
		ptr->ptr <<= 6;
		ptr->sr |= 1;
		ptr->ptr |= c & 077;
		if(!ptr->b)
			ptr->ptr |= c & 0300;
	}
	if(!ptr->b || ptr->sr & 040){
		ptr->busy = 0;
		ptr->flag = 1;
	}else
		goto next;
	recalc_ptr_req(ptr);
}

static void
wake_ptp(void *dev)
{
	Ptp *ptp;
	IOBus *bus;

	ptp = dev;
	bus = ptp->bus;
	if(IOB_RESET){
		ptp->pia = 0;
		ptp->busy = 0;
		ptp->flag = 0;
		ptp->b = 0;
	}
	if(bus->devcode == PTP){
		if(IOB_STATUS){
			if(ptp->b) bus->c12 |= F30;
			if(ptp->busy) bus->c12 |= F31;
			if(ptp->flag) bus->c12 |= F32;
			bus->c12 |= ptp->pia & 7;
		}
		if(IOB_CONO_CLEAR){
			ptp->pia = 0;
			ptp->busy = 0;
			ptp->flag = 0;
			ptp->b = 0;
		}
		if(IOB_CONO_SET){
			if(bus->c12 & F30) ptp->b = 1;
			if(bus->c12 & F31) ptp->busy = 1;
			if(bus->c12 & F32) ptp->flag = 1;
			ptp->pia |= bus->c12 & 7;
		}
		if(IOB_DATAO_CLEAR){
			ptp->ptp = 0;
			ptp->busy = 1;
			ptp->flag = 0;
			ptp->waitdatao = 0;
		}
		if(IOB_DATAO_SET){
			ptp->ptp = bus->c12 & 0377;
			ptp->waitdatao = 1;
		}
	}
	recalc_ptp_req(ptp);
}

static void
wake_ptr(void *dev)
{
	Ptr *ptr;
	IOBus *bus;

	ptr = dev;
	bus = ptr->bus;
	if(IOB_RESET){
		ptr->pia = 0;
		ptr->busy = 0;
		ptr->flag = 0;
		ptr->b = 0;
	}

	if(bus->devcode == PTR){
		if(IOB_STATUS){
			if(ptr->motor_on) bus->c12 |= F27;
			if(ptr->b) bus->c12 |= F30;
			if(ptr->busy) bus->c12 |= F31;
			if(ptr->flag) bus->c12 |= F32;
			bus->c12 |= ptr->pia & 7;
		}
		if(IOB_DATAI){
			bus->c12 |= ptr->ptr;
			ptr->flag = 0;
			// actually when DATAI is negated again
			ptr->busy = 1;
		}
		if(IOB_CONO_CLEAR){
			ptr->pia = 0;
			ptr->busy = 0;
			ptr->flag = 0;
			ptr->b = 0;
		}
		if(IOB_CONO_SET){
			if(bus->c12 & F30) ptr->b = 1;
			if(bus->c12 & F31) ptr->busy = 1;
			if(bus->c12 & F32) ptr->flag = 1;
			ptr->pia |= bus->c12 & 7;
		}
	}
	recalc_ptr_req(ptr);
}

void
ptr_setmotor(Ptr *ptr, int m)
{
	if(ptr->motor_on == m)
		return;
	ptr->motor_on = m;
	if(ptr->motor_on)
		ptr->busy = 0;
	ptr->flag = 1;
	recalc_ptr_req(ptr);
}

static void
ptpattach(Device *dev, const char *path)
{
	Ptp *ptp;
	int fd;

	ptp = (Ptp*)dev;
	fd = ptp->fd;
	if(fd >= 0){
		ptp->fd = -1;
		close(fd);
	}
	ptp->fd = open(path, O_WRONLY | O_CREAT, 0666);
	if(ptp->fd < 0)
		fprintf(stderr, "couldn't open file %s\n", path);
}

static void
ptrattach(Device *dev, const char *path)
{
	Ptr *ptr;
	int fd;

	ptr = (Ptr*)dev;
	fd = ptr->fd;
	if(fd >= 0){
		ptr->fd = -1;
		close(fd);
	}
	ptr->fd = open(path, O_RDONLY);
	if(ptr->fd < 0)
		fprintf(stderr, "couldn't open file %s\n", path);
}

static void
ptrioconnect(Device *dev, IOBus *bus)
{
	Ptr *ptr;
	ptr = (Ptr*)dev;
	ptr->bus = bus;
	bus->dev[PTR] = (Busdev){ ptr, wake_ptr, 0 };
}

static void
ptpioconnect(Device *dev, IOBus *bus)
{
	Ptp *ptp;
	ptp = (Ptp*)dev;
	ptp->bus = bus;
	bus->dev[PTP] = (Busdev){ ptp, wake_ptp, 0 };
}

Device*
makeptp(int argc, char *argv[])
{
	Ptp *ptp;
	Thread th;

	ptp = malloc(sizeof(Ptp));
	memset(ptp, 0, sizeof(Ptp));

	ptp->dev.type = ptp_ident;
	ptp->dev.name = "";
	ptp->dev.attach = ptpattach;
	ptp->dev.ioconnect = ptpioconnect;
	ptp->fd = -1;

	th = (Thread){ nil, ptpcycle, ptp, 1, 0 };
	addthread(th);
	return &ptp->dev;
}

Device*
makeptr(int argc, char *argv[])
{
	Ptr *ptr;
	Thread th;

	ptr = malloc(sizeof(Ptr));
	memset(ptr, 0, sizeof(Ptr));

	ptr->dev.type = ptr_ident;
	ptr->dev.name = "";
	ptr->dev.attach = ptrattach;
	ptr->dev.ioconnect = ptrioconnect;
	ptr->fd = -1;

	th = (Thread){ nil, ptrcycle, ptr, 1, 0 };
	addthread(th);
	return &ptr->dev;
}