#!/bin/bash

# Copyright (C) 2024 Nicolás Ortega Froysa <nicolas@ortegas.org> All rights reserved.
# Author: Nicolás Ortega Froysa <nicolas@ortegas.org>
#
# This software is provided 'as-is', without any express or implied
# warranty. In no event will the authors be held liable for any damages
# arising from the use of this software.
#
# Permission is granted to anyone to use this software for any purpose,
# including commercial applications, and to alter it and redistribute it
# freely, subject to the following restrictions:
#
# 1. The origin of this software must not be misrepresented; you must not
#    claim that you wrote the original software. If you use this software
#    in a product, an acknowledgment in the product documentation would be
#    appreciated but is not required.
#
# 2. Altered source versions must be plainly marked as such, and must not be
#    misrepresented as being the original software.
#
# 3. This notice may not be removed or altered from any source
#    distribution.

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"