#! /bin/bash

# JConf, a JupyterHub user manager. Manages system users and links them with jupyterhub accounts.
# Version 0.1 - 24th Nov, 2025
# MIT Licensed, by The Grammer Society


# required options:
# setup: must be run after downloaded. Will create a new venv in /opt, installs jupyterhub, lab and notebook. Checks if npm is installed, then installs configurable http server, installs itself to /usr/bin. Installs service file, enables and starts it. Adds root to admins.
# adduser: creates a system user, asks for password, calls jupyterhub api to create a new user, adds penv to user, su user, penv init and penv creates a default environment. Also copy some instructions in readme file.
# deluser: deletes jupyterhub user, deletes user home, deletes user profile from system.
# start: starts the server, systemd call
# stop: stops the server, systemd call

title() {
    echo "JConf: JupyterHub Configuration Manager."
}

usage() {
    echo "Must run as root."
    echo "Usage: jconf <command> <args>"
    echo ""
    echo "User Management Commands:"
    echo " - adduser <name>"
    echo " - deluser <name>"
    echo " - listusers"
    echo ""
    echo "Server Management Commands:"
    echo " - start"
    echo " - stop"
    echo " - install"
    echo " - uninstall"
}


if [ "$#" -lt 1 ]; then
    title
    usage
    exit 1
fi

cmd=$1
case "$cmd" in
    adduser)

        exist=$(awk -F: -v username="$2" '{if ($1 == username && $3 >= 1000 && $1 != "nobody") {print 1; found=1; exit}} END {if (!found) print 0}' /etc/passwd)
        if [ "$exist" -eq  1 ]; then
            echo "$2 user already exists"
        else
            while true; do
                read -rp "Do you want to create an user account $2 [Y/n]:" yn
                case $yn in
                    [Yy]* ) 
                        useradd "$2";
                        echo "Enter the password for $2:";
                        passwd "$2"
                        echo "$2 user account created successfully";
                        break;;
                    [Nn]* ) exit 1;;
                    * ) echo "Please answer Y or N.";;
                esac
            done
        fi
        exit 1
        ;;
    
    deluser)

        exist=$(awk -F: -v username="$2" '{if ($1 == username && $3 >= 1000 && $1 != "nobody") {print 1; found=1; exit}} END {if (!found) print 0}' /etc/passwd)
        if [ "$exist" -eq  0 ]; then
            echo "$2 user doesn't exist"
            exit 1
        else

            while true; do
                read -rp "Do you want to delete $2 user account? [Y/n]:" yn
                case $yn in
                    [Yy]* ) 
                        userdel -rRZ "$2";
                        echo "$2 user account deleted successfully";
                        break;;
                    [Nn]* ) exit 1;;
                    * ) echo "Please answer yes or no.";;
                esac
            done
        fi
        exit 1
        ;;
        
    listusers)
        husers=$(awk -F: '{ if ($3 >= 1000 && $1 != "nobody" ) {print $1}}' /etc/passwd)
        echo $husers
        ;;
    
    start)
        echo
        ;;
    stop)
        echo
        ;;
    install)
        echo
        ;;
    uninstall)
        echo
        ;;
    *)
        echo
        ;;
esac