#!/usr/bin/env bash

# grab parameters, trim whitespaces
length="${*// }";

# look for easy mode "-e"
if [[ "$length" =~ ^-e$ ]]; then
	passw=$(cat /dev/urandom | tr -cd 'a-z0-9' | head -c 32);
	echo $passw | tr -d '\n' | xclip -selection c;
	echo $passw
	exit 0
elif [[ "$length" =~ ^-e=([0-9]+)$ ]]; then
	# get length from regex	
	len=${BASH_REMATCH[1]};
	passw=$(cat /dev/urandom | tr -cd 'a-z0-9' | head -c "$len");
	echo $passw | tr -d '\n' | xclip -selection c;
	echo $passw
	exit 0
# look for -b=bytes
elif [[ "$length" =~ ^-b=([0-9]+)$ ]]; then
	# set bytes
	bytes=${BASH_REMATCH[1]};
	# set length
	let length=4*bytes/3+1;
	# instead of ceiling the function, we just floor it and add 1, because the output length was specified in bytes
else
	if [[ -z "$length" ]]; then
		# if no parameters were given, the default is used
		length=32
		bytes=24
	else
		if ! [[ "$length" =~ ^[0-9]+$ ]]; then
			echo -e "\e[91mError: '$length' is not a number!\e[0m";
			exit 100;
		fi

		# calculate the bytes from the length
		let bytes=30*length/4;
		# ceil the result using python

		bytes=$(python -c "from math import ceil; print ceil($bytes/10.0)" | tr -d '.0');
	fi
fi

# generate the password
password=$(dd if=/dev/urandom bs=1 count="$bytes" 2>/dev/null | base64);

# idk why but they keep adding a newline after every 76th character, compensate for that!
let length=length+length/77;

# cut it and echo it
echo "${password:0:$length}" | tr -d '\n';

# we removed the newlines from the middle of the password adn from the end, add the one at the end back
echo "";

# copy the password to clipboard
echo "${password:0:$length}" | tr -d '\n' | xclip -selection c;

exit 0;