#!/bin/bash

set -e
if [[ $# != 2 ]]; then
   echo "$0 <encode_script.pl> <crack_script.pl>"
   exit 1
fi

function die() {
   echo "FAIL: $1"
   exit 1
}

ENCODE=$1
CRACK=$2
if [[ ! -r $ENCODE ]]; then
   die "$ENCODE is is not readable"
fi
if [[ ! -r $CRACK ]]; then
   die "$CRACK is is not readable"
fi

PLAINTEXT=$(cat <<EOT
Alice took up the fan and gloves, and, as the hall was very hot, she
kept fanning herself all the time she went on talking: "Dear, dear!  How
queer everything is to-day!  And yesterday things went on just as usual.
I wonder if I've been changed in the night? Let me think: was I the
same when I got up this morning?  I almost think I can remember feeling a
little different.  But if I'm not the same, the next question is, Who
in the world am I?  Ah, THAT'S the great puzzle!"  And she began thinking
over all the children she knew that were of the same age as herself, to
see if she could have been changed for any of them.
EOT
)

# Test various key lengths.  All these should succeed.
for key in "a" "n" "xy" "egg" "banana" "redqueen" "contrariwise"; do
   expected=$(echo $key | perl -ne 'print uc')
   actual=$(echo $PLAINTEXT | perl $ENCODE $key | perl $CRACK | head -1)
   [[ "$expected" == "$actual" ]] || die "key=$key"
done

# Test that bad input will not crash the script.
output=$(echo "" | perl $CRACK)
[[ $? == 0 ]] || die "Unexpected failure"
[[ "$output" == "" ]] || die "Unexpected output"

dont_care=$(perl -e 'print "a" x 1000' | perl $CRACK)
[[ $? == 0 ]] || die "Unexpected failure"

echo "$0: OK"