#!/bin/bash

echo "Content-type: text/plain"
echo ""

# get form data: pattern=....&excludeList=...&includeList=...
export stdin="$(cat)"

# when pattern has 3 or more dots, safari may pass an extended ascii sequence
# if so, convert that sequence to 3 dots ...
	
# https://www.w3schools.com/tags/ref_urlencode.ASP # search for %E2%80%A6
threeDots=`printf "\342\200\246"`

stdin=`echo $stdin | sed "s+$threeDots+...+g" `

# now perform input validation
illegal=`echo "$stdin" | sed -e 's+[A-Za-z=& .%0-9]*++g'`

if [ ! -z "$illegal" ]
then
	#tmp=`mktemp`.wordle.log
	#echo "`date`: error: illegal character(s); stdin = $stdin" >> $tmp
	#echo "error: illegal character(s): $illegal ... see also $tmp"
       	echo ""
	echo "error: illegal character(s): $illegal"
       	echo ""
	#echo "stdin = ($stdin)"
       	#echo ""

	# echo $stdin | sed "s+$threeDots+...+g"

       	#echo ""
	#echo "$stdin" | od -cv
       	#echo ""
	#echo "$stdin" | od -v -t x1
       	echo ""
	exit 0
fi

# construct variables from input
for kv in `echo $stdin | sed -e 's+&+ +g'`
do
	eval "$kv"
done

# echo stdin = $stdin
# echo pattern = $pattern
# echo excludeList = $excludeList
# echo includeList = $includeList

####################################

if [ ! -z "$excludeList" ]
then
    # open bracket, ^ symbol, char list (with ws or %20 removed), close bracket
    key=`echo $excludeList | sed -e "s+^.+[^&+g" -e 's+%20++g' -e "s+[ ]*++g" -e "s+$+]+g" `

    # replace "." in pattern with above key
    pattern=`echo $pattern | sed -e "s+\.+$key+g"`
fi

####################################

tmp=`mktemp`
cat /usr/share/dict/words | egrep -v "[A-Z]" | egrep "^${pattern}$" > $tmp

####################################

if [ -z "$includeList" ]
then
    # if include list is empty, then return early
    cat $tmp
else
    # convert %20 to space, so we can grep for each letter individually
    
    for letter in `echo $includeList | sed -e 's+%20+ +g'`
    do 
	cat $tmp | egrep "$letter" > $tmp.2
	mv $tmp.2 $tmp
    done 

    cat $tmp
fi

# cleanup
/bin/rm -f $tmp