#!/bin/bash
# This is free and unencumbered software released into the public domain.
#
# Anyone is free to copy, modify, publish, use, compile, sell, or
# distribute this software, either in source code form or as a compiled
# binary, for any purpose, commercial or non-commercial, and by any
# means.
#
# In jurisdictions that recognize copyright laws, the author or authors
# of this software dedicate any and all copyright interest in the
# software to the public domain. We make this dedication for the benefit
# of the public at large and to the detriment of our heirs and
# successors. We intend this dedication to be an overt act of
# relinquishment in perpetuity of all present and future rights to this
# software under copyright law.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
#
# For more information, please refer to <http://unlicense.org/>

VERSION="1.0"

function print_usage() {
	echo "USAGE: d6 [OPTIONS]"
}

function print_help() {
	print_usage
	echo "OPTIONS:
	-v          print program version
	-h          print this help information
	-n <num>    number of words in generated password (default 3)
	-f <file>   custom dictionary file (default
	            ~/.local/share/wordlist.txt)
	-d <delim>  delimiter used between words (default \"\", i.e. NONE)
	-c <case>   the case used for the generated words, can be: upper,
	            lower, capital (default \"capital\")"
}

function test_case() {
	if [ $1 != "lower" ] && [ $1 != "upper" ] && [ $1 != "capital" ]
	then
		return 1
	else
		return 0
	fi
}

NUM_WORDS=3
WORDLIST="$HOME/.local/share/wordlist.txt"
DELIMITER=""
CASE="capital"

while getopts "vhn:f:d:c:" arg
do
	case $arg in
		v)
			echo "d6 v$VERSION"
			exit 0;;
		h)
			print_help
			exit 0;;
		n)
			NUM_WORDS=$OPTARG;;
		f)
			WORDLIST="$OPTARG";;
		d)
			DELIMITER="$OPTARG";;
		c)
			if test_case $OPTARG
			then
				CASE="$OPTARG"
			else
				echo "'$OPTARG' is an invalid case. Use 'capital', 'lower', or 'upper'."
				exit 1
			fi;;
		?)
			print_usage
			exit 2
	esac
done

WORDS=""

for i in $(seq 1 $NUM_WORDS)
do
	ROLLS=""
	for j in {1..5}
	do
		ROLLS="$((1 + $RANDOM % 6))$ROLLS"
	done

	if [ $CASE == "upper" ]
	then
		WORD="$(awk "/$ROLLS/{ print toupper(\$2) }" $WORDLIST)"
	elif [ $CASE == "lower" ]
	then
		WORD="$(awk "/$ROLLS/{ print tolower(\$2) }" $WORDLIST)"
	else
		WORD="$(awk "/$ROLLS/{ print \$2 }" $WORDLIST)"
		WORD="${WORD^}"
	fi

	if [ $i -eq $NUM_WORDS ]
	then
		WORDS="${WORDS}${WORD}"
	else
		WORDS="${WORDS}${WORD}${DELIMITER}"
	fi
done

echo "$WORDS"