#!/bin/bash
#

# if exists remove old pages directoryr and create a new one to put the pages in
	if [ -d pages ]
then
   rm -r pages
fi
mkdir pages

# wite all output in bold
echo -en "\033[1;35m"

# get current time seconds and minutes to use as random seed
s=$(date +%S)
m=$(date +%M)

# set number of pages (200 for +50'000 words)
pages=100
echo "pages:"$pages
# create random number of times the stamp is applied (within a given reasonable range)
stamps=$(awk -v s="$s" -v m="$m" 'BEGIN{srand(int(s*23/m));x=int(160+rand()*200); print x}')
echo "stamps:"$stamps

# init some counters
r=0
j=0

# start creating pages
until [ $j -gt $pages ]
do
   # inform about current page being processed
   echo "page:"$j" of "$pages

   ((j+=1))

   # create a blank and white a4 sized page
   echo "cretae empty page..."
   convert -size 2480x3508 xc:white page.png

   # init conter and get new random seeds values per page
   i=0
   s=$(date +%S)
   m=$(date +%M)

   # create random center offset
   c=$(awk -v s="$s" -v m="$m" 'BEGIN{srand(s*m);x=rand()-0.5; print x}')
   echo "rand c:"$c

   # create random angle increase and desnity
   ir=$(awk -v s="$s" -v m="$m" 'BEGIN{srand(s);x=int(1+rand()*5); print x}')
   echo "rand ir:"$ir

   # create random smear factor
   e=$(awk -v s="$s" -v m="$m" 'BEGIN{srand(s*10-m);x=int(10+rand()*90); print x}')
   echo "rand e:"$e


   # cretae the circle composition
   echo "compose circle..."
   until [ $i -gt $stamps ] 
   do
      # print iteration
      echo -en "\033[1B $i \033[1A\033[6D"

      # increase counters
      ((i+=1))
      ((r+=ir))

      # rotate base image
      magick orig.png -rotate $r -resize 350x350 copy.png

      # calculate the position
      cx=$(awk -v i="$i" -v c="$c" 'BEGIN{ out=2480*(0.5-0.8*c)+20*c*i; print out }')
      cy=$(awk -v i="$i" -v c="$c" -v e="$e" 'BEGIN{ out=3508*(0.5-0.9*c)+e*c*i; print out }')
      rx=$(awk -v i="$i" -v c="$c" 'BEGIN{ out=800+3*c*i; print out }')
      ry=$(awk -v i="$i" -v c="$c" 'BEGIN{ out=800+7*c*i; print out }')
      a=$(awk -v r="$r" 'BEGIN{ out=r/360*2*3.14159; print out }')

      x=$(awk -v cx="$cx" -v a="$a" -v rx="$rx" 'BEGIN {v=cx+rx*cos(a); print v }')
      y=$(awk -v cy="$cy" -v a="$a" -v ry="$ry" 'BEGIN {v=cy+ry*sin(a); print v }')

      # compose to a new image
      magick composite copy.png page.png -compose Multiply -geometry +$x+$y page.png
   done
   # move created pages to pages folder
   mv page.png ./pages/page$j.png
done

# create "unique" time stamp for book filename
ts=$(date +%H%S%M)

# convert and attach all pages into a pdf file
convert ./pages/*.png ./book_$ts.pdf
mv ./pages ./pages_$ts