#!/bin/bash

SRC="tube.dat"
DST="result.dat"
DBG="debug.dat"
IMG="debug.png"

rm -f $DST
rm -f $DBG
rm -f $IMG

awk -v DST=$DST -v DBG=$DBG '
function getSurface(s1,s2,s3, S) {
  S[A] = ((s2[Y]-s1[Y])*s3[Z]+(s1[Y]-s3[Y])*s2[Z]+(s3[Y]-s2[Y])*s1[Z]);
  S[B] = ((s1[X]-s2[X])*s3[Z]+(s3[X]-s1[X])*s2[Z]+(s2[X]-s3[X])*s1[Z]);
  S[C] = ((s2[X]-s1[X])*s3[Y]+(s1[X]-s3[X])*s2[Y]+(s3[X]-s2[X])*s1[Y]);
  S[D] = (s2[X]*s1[Y]-s1[X]*s2[Y])*s3[Z]+(s1[X]*s3[Y]-s3[X]*s1[Y])*s2[Z]+(s3[X]*s2[Y]-s2[X]*s3[Y])*s1[Z];
}
function getLength(S,p) {
  a = (S[A]*p[X]+S[B]*p[Y]+S[C]*p[Z]+S[D]);
  b = sqrt(S[A]*S[A]+S[B]*S[B]+S[C]*S[C]);
  return a/b;
}
function solve(s1,s2,s3,s4,s5,s6, p1,p2, l,i) {
  getSurface(s1,s2,s3, S1);
  getSurface(s4,s5,s6, S2);
  l0=getLength(S1,p1); l1=getLength(S2,p1);
  l2=getLength(S1,p2); l3=getLength(S2,p2);
  ll[i+0] = l[i+0];
  ll[i+1] = l[i+1];
  l[i+0]=l0*l1;
  l[i+1]=l2*l3;
  cnt=cnth=0;
  if(l[i+0]<0) cnth++;
  if(l[i+1]<0) cnth++;
  if(l[i+0]<-1E-20) cnt++;
  if(l[i+1]<-1E-20) cnt++;
  if(cnt==2) return 1;
  if(cnt==1&&cnth==2) return 1;
  if(cnt>=1)
  {
    if(ll[i+0]<0) cnth++;
    if(ll[i+1]<0) cnth++;
    if(ll[i+0]<-1E-20) cnt++;
    if(ll[i+1]<-1E-20) cnt++;
    if(cnt>=2) return 1;
    if(cnt==1&&cnth>=2) return 1;
  }
  return 0;
}
BEGIN{
  i=0;count=0;
  X=0;Y=1;Z=2;
  A=0;B=1;C=2;D=3;
}
/^#/{next}
{
  if(NF!=20) next;

  if(i!=0)
  {
    s4[X]=$12-b1[X]; s4[Y]=$13-b1[Y]; s4[Z]=$14-b1[Z];
    s5[X]=$15-b1[X]; s5[Y]=$16-b1[Y]; s5[Z]=$17-b1[Z];
    s6[X]=$18-b1[X]; s6[Y]=$19-b1[Y]; s6[Z]=$20-b1[Z];

    res = 0;
    res1=solve(s1,s2,s3,s4,s2,s3, s5,s6, l,0);
    res2=solve(s1,s2,s3,s1,s5,s3, s4,s6, l,2);
    res3=solve(s1,s2,s3,s1,s2,s6, s4,s5, l,4);
    res4=solve(s4,s5,s6,s1,s5,s6, s2,s3, l,6);
    res5=solve(s4,s5,s6,s4,s2,s6, s1,s3, l,8);
    res6=solve(s4,s5,s6,s4,s5,s3, s1,s2, l,10);
    if(res1||res4) res++;
    if(res2||res5) res++;
    if(res3||res6) res++;

    printf i " " $1 " " > DBG
    for(j=0;j<12;j++) printf l[j] " " > DBG
    print res > DBG

    if(res!=0) {
      count++;
      print i, $1, res > DST
    }
  }
  b1[X]=$12; b1[Y]=$13; b1[Z]=$14;
  s1[X]=$12-b1[X]; s1[Y]=$13-b1[Y]; s1[Z]=$14-b1[Z];
  s2[X]=$15-b1[X]; s2[Y]=$16-b1[Y]; s2[Z]=$17-b1[Z];
  s3[X]=$18-b1[X]; s3[Y]=$19-b1[Y]; s3[Z]=$20-b1[Z];
  i++
}
END{print "count:", count > DST}
' $SRC

function paint() {
  W=$(tail -n 1 $DBG | awk '{print $1}')
  H=`awk 'BEGIN{max=0} END{print max/20} {cur=($2+$3+$4+$5+$6+$7)/6; if(max<cur) max=cur}' $DBG`
  echo "set terminal png size 1000, 800"
  echo "set output '$IMG'"
  echo "set xrange [0:$W]"
  echo "set xzeroaxis lt -1"
  echo "set grid xtics ytics mxtics mytics"

  awk -v W=$W '/^count/{next} {print $1, $2, $1-0.5, $1-0.5+W/64, $1-0.5+W*2/64}' $DST |
  while read i; do
    a=( $i )
    echo "LABEL = \"(${a[0]},${a[1]})\""
    echo "set obj rect at ${a[4]},$H size char strlen(LABEL)-1, char 1 fc rgb \"cyan\" fillstyle solid 1"
    echo "set label at ${a[4]},$H LABEL front center"
    echo "set arrow from ${a[2]},0 to ${a[3]},$H*0.7 nohead lc -1 linewidth 1"
  done

  echo "plot \"$DBG\" using 1:3 with line, "\
            "\"$DBG\" using 1:4 with line, "\
            "\"$DBG\" using 1:5 with line, "\
            "\"$DBG\" using 1:6 with line, "\
            "\"$DBG\" using 1:7 with line, "\
            "\"$DBG\" using 1:8 with line"
}
#paint | gnuplot
#eog $IMG