{ pkgs, lib, config, specialArgs, options, modulesPath }:

with pkgs;

let

    git-identity = (writeShellApplication {
        name = "git-identity";
        text = ''
#!/usr/bin/env bash

IFS=""

function print_menu()  # selected_item, ...menu_items
{
	local function_arguments=("''$@")

	local selected_item="''$1"
	local menu_items=("''${function_arguments[@]:1}")
	local menu_size="''${#menu_items[@]}"

	for (( i = 0; i < menu_size; ++i ))
	do
		if [ "''$i" = "''$selected_item" ]
		then
			echo -e "\033[1;34m > \033[0m\e[1m''${menu_items[i]}\033[0m"
		else
			echo "   ''${menu_items[i]}"
		fi
	done
}

function run_menu()  # selected_item, ...menu_items
{
	local function_arguments=("''$@")

	local selected_item="''$1"
	local menu_items=("''${function_arguments[@]:1}")
	local menu_size="''${#menu_items[@]}"
	local menu_limit=''$((menu_size - 1))

	print_menu "''$selected_item" "''${menu_items[@]}"
	
	while read -rsn1 input
	do
		case "''$input"
		in
			''$'\x1B')  # ESC ASCII code (https://dirask.com/posts/ASCII-Table-pJ3Y0j)
				read -rsn1 -t 0.1 input
				if [ "''$input" = "[" ]  # occurs before arrow code
				then
					read -rsn1 -t 0.1 input
					case "''$input"
					in
						A)  # Up Arrow
							if [ "''$selected_item" -ge 1 ]
							then
								selected_item=''$((selected_item - 1))
								echo -en "\033[s\033[''${menu_size}A"
								print_menu "''$selected_item" "''${menu_items[@]}"
								echo -en "\033[u\033[0m"
							fi
							;;
						B)  # Down Arrow
							if [ "''$selected_item" -lt "''$menu_limit" ]
							then
								selected_item=''$((selected_item + 1))
								echo -en "\033[s\033[''${menu_size}A"
								print_menu "''$selected_item" "''${menu_items[@]}"
								echo -en "\033[u\033[0m"
							fi
							;;
					esac
				fi
				read -rsn5 -t 0.1  # flushing stdin
				;;
			"")  # Enter key
        echo "enter key"
				return "''$selected_item"
				;;
		esac
	done
}


# Usage example:

selected_item=0
menu_items=("Stephan Stanisic <s.stanisic@student.uu.nl>"
	"Stephan Stanisic <s.stanisic@ru.nl>"
	"Stephan Stanisic <stephan@stanisic.nl>" 
	"Steph <steph+noreply@code.steph.tools>")

run_menu "''$selected_item" "''${menu_items[@]}"
menu_result="''$?"

echo

sel=''${menu_items[''$menu_result]}

name=''$(echo "''$sel" | cut -d \< -f 1 | head -c -2)
email=''$(echo "''$sel" | cut -d \< -f 2 | head -c -2)

echo "Setting username to ''$name and email to ''$email"

git config user.email "''$email"
git config user.name "''$name"

        '';
    });

in
{
  environment.systemPackages = [ git-identity ];
}