/* dmxin.c   by Michael Thorpe   2019-02-07 */

#include <curses.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "runner.h"

struct dmx dmxin={len:0,fd:-1,sawFE:0,pos:-1};

static void dmxin_redraw() {
	dmx_redraw(&dmxinframe,&dmxin);
}

enum chancmp_t {GOOD,LOW,HIGH,UNKNOWN};
static enum chancmp_t chancmp[1+DMX_MAXCHAN];
static int dmxin_offset=0;
static char titlebar[13];
void dmxin_setoffset(int new) {
	int i;
	if(-1==new)
		new=dmxin_offset;
	if(0==new) {
		dmxinframe.title="DMX IN";
	} else {
		snprintf(titlebar,sizeof(titlebar),"DMX IN (%d)",new);
		dmxinframe.title=titlebar;
	}
	if(dmxinframe.h && dmxinframe.w)
		draw_titlebar(&dmxinframe);
/* Update the actual variable and pin the channels */
	dmxin_offset=new;
	for(i=1;i<=DMX_MAXCHAN;i++)
		chancmp[i]=UNKNOWN;
}

void dmxin_unlinkchan(int chan) {
	chancmp[chan]=UNKNOWN;
}

static void gotchan(struct dmx *dmx,unsigned char val) {
	unsigned char curval;
	if(0==dmx->pos) {
		if(val)
			dmx->pos=-1; /* throw out packets with non-NULL START codes */
		else
			dmx->pos++;
		return;
	}
	if(-1==dmx->pos)
		return;
	if(DMX_MAXCHAN<dmx->pos)
		return;
	if(&dmxin==dmx)
		show_new_chan(&dmxinframe,dmx->pos,val);
	if(dmx->len<dmx->pos)
		dmx->len=dmx->pos;
	dmx->data[dmx->pos]=val;
/* FIXME: We should update the looks frame here if applicable. */
	if(&dmxin==dmx && editlook) {
		if(DMX_MAXCHAN<dmxin_offset+dmx->pos)
			goto done;
		if(GOOD != chancmp[dmx->pos]) {
			curval=editlook->func(editlook,dmxin_offset+dmx->pos);
			switch(chancmp[dmx->pos]) {
			case GOOD:
/* Useless case, but it shuts up the compiler. */
				break;
			case LOW:
				if(val<curval)
					goto done;
				chancmp[dmx->pos]=GOOD;
				break;
			case HIGH:
				if(curval<val)
					goto done;
				chancmp[dmx->pos]=GOOD;
				break;
			case UNKNOWN:
				if(val<curval) {
					chancmp[dmx->pos]=LOW;
					goto done;
				}
				if(curval<val) {
					chancmp[dmx->pos]=HIGH;
					goto done;
				}
				chancmp[dmx->pos]=GOOD;
				break;
			}
		}
		while(editlook->dmx->len<dmxin_offset+dmx->pos)
			editlook->dmx->data[++editlook->dmx->len]=0;
		editlook->dmx->data[dmxin_offset+dmx->pos]=val;
	}
done:
	dmx->pos++;
}

void dmx_readable(struct dmx *dmx) {
	unsigned char buf[1028];
	int i,l;
	l=read(dmx->fd,buf,sizeof(buf));
	if(-1==l) {
		perror("read");
		exit(-1);
	}
	if(0==l) {
		errmsg("short read from proc");
		dmx->len=0;
		dmx->fd=-1;
		if(&dmxin==dmx) /* somebody probably unplugged the Teensy */
			dmxin_redraw();
		return;
	}
	for(i=0;i<l;i++) {
		if(0xFE==buf[i]) {
			dmx->sawFE=1;
			continue;
		}
		if(dmx->sawFE) {
			switch(buf[i]) {
			case 0: /* BREAK */
				if(-1 != dmx->pos)
					dmx->len=dmx->pos;
				dmx->pos=0;
				break;
			case 1: /* literal FE */
				gotchan(dmx,0xFE);
				break;
			case 2:
				dmx->pos=-1;
				break;
			default:
				fprintf(stderr,"Got %2.2X from DMX %p fd %d\n",buf[i],dmx,dmx->fd);
				exit(-1);
			}
			dmx->sawFE=0;
			continue;
		}
		gotchan(dmx,buf[i]);
	}
}

struct frame dmxinframe={draw:dmxin_redraw};