#!/usr/bin/env bash

roll_dice() {
local diceString="${1,,}"
local modifier="${2:-0}"
local number
local sides

if [[ "${diceString}" != "${diceString//d/}" ]]; then

IFS='d' read -r number sides <<< "$diceString"
fi

if [[ "${diceString:0:1}" == "d" ]]; then
number=1
sides="${diceString//d/}"
fi
number=${number:-1}
sides=${sides:-6}

if [[ "$modifier" =~ ^[+-]?[0-9]+$ ]]; then
modifier=$((modifier))
fi

randomNumbers=$(shuf -i 1-$sides -n $number | tr '\n' ' ')
IFS=' ' read -r -a numbersArray <<< "$randomNumbers"
joinedNumbers=$(IFS=,; echo "${numbersArray[*]}")

sum=0
for num in "${numbersArray[@]}"; do
sum=$((sum + num))
done
sum=$((sum + modifier))

echo "Dice rolls: $joinedNumbers Modifier: $modifier"
echo "Total: $sum"
}

roll_dice "$1" "$2"