#!/bin/bash
# User Management Script, powered by an SQL database
# (c) Sangelo | Read Licenses for more info: https://gitpot.dev/sangelo/user-mgmt

# Variables
E_BADARGS=65
MYSQL=`which mysql`
MYSQL_USER="root"
USAGE="
$0 -- user management script
Usage:
    init
    add     {username} {name} {description}
    delete  {username}
    list
"

# Check for correct number of arguments and action
if [ $# -lt 1 ]
then
  echo "$USAGE"
  exit $E_BADARGS
fi

# Switch between different actions
case "$1" in
  "init")
    Q1="CREATE SCHEMA if not exists usermgmt; use usermgmt; CREATE TABLE if not exists users (username varchar(255), name varchar(255), description varchar(255));"
    SQL="${Q1}"
    ;;

  "add")
    if [ $# -ne 4 ]
    then
      echo "Error: Invalid action."
      echo "$USAGE"
      exit $E_BADARGS
    fi
    Q1="INSERT INTO usermgmt.users (username, name, description) VALUES ('$2', '$3', '$4');"
    SQL="${Q1}"
    PASSWORD=`openssl rand -base64 12`
    useradd -m -p "$PASSWORD" "$2"
    echo "$PASSWORD" > "/home/$2/password.txt"
    echo "This is your password. Please delete this file after saving the password." >> "/home/$2/password.txt"
    ;;

    "delete")
    if [ $# -ne 2 ]
    then
        echo "Error: Invalid action."
        echo "$USAGE"
        exit $E_BADARGS
    fi
    echo -n "Are you sure you want to delete user "$2"? [y/N] "
    read confirm
    if [ "$confirm" = "y" ] || [ "$confirm" = "Y" ]
    then
        Q1="DELETE FROM usermgmt.users WHERE username = '$2';"
        SQL="${Q1}"
        userdel -r "$2"
    else
        echo "User deletion cancelled."
        exit 0
    fi
    ;;

  "list")
    if [ $# -ne 1 ]
    then
      echo "Error: Invalid action."
      echo "$USAGE"
      exit $E_BADARGS
    fi
    Q1="SELECT username, name, description FROM usermgmt.users;"
    SQL="${Q1}"
    ;;

  *)
    echo "Error: Invalid action. Please use a valid argument."
    echo "$USAGE"
    exit $E_BADARGS
    ;;
esac

echo "Creating MySQL connection... Enter your password if prompted."
$MYSQL -u "$MYSQL_USER" -p -e "$SQL"
echo "Done."