#!/usr/bin/env bash


## name:       sconfig.sh
## author:     david@socialnerds.org
## version:    0.1
##
## decription: This is a script to help you configure
##             various aspects of a linux server.
##
## features:   manage user accounts and their keys
##             update operating system packages
##             install admin tools
##             harden sshd
##             enable ufw
##             setup docker
##             setup nginx & acme.sh
##             setup duplicity
##             setup snmpd
##
## usage:      ./sconfig.sh
##
## changelog:  2020-06-29 - implemented basic features, not quite there yet
##             2020-06-22 - first draft of a working menu
##             2020-06-21 - started development of v0.1


# **** start of script ****

#  ****  bash trap initialisation  ****
trap bashtrap INT

## functions

#detect Ctrl-c
bashtrap() {
  header
  echo "Detected Ctrl-C"; echo "Dropping to shell"; sleep 1
  clear; exit 0

}

#print header
header() {
  clear
  local cols=$(tput cols); local char="="
  if [ $cols -gt 59 ]; then
    local i=0; while [ $i != $((cols)) ]; do local chars="$chars$char"; i=$((i+1)); done
    echo $chars; echo "Server configuration"; echo -e "$chars\n"
  else
    echo "error: terminal not wide enough (it must be at least 60 characters wide)"; exit 1
  fi
}

#print content
content() {
  local lines=$(tput lines)
  if [ $lines -gt 14 ]; then
    for i in $(seq 1 $#); do
      echo "${!i}"
    done
    local l=5; while [ $l != $((lines-$#)) ]; do echo ""; l=$((l+1)); done
  else
    clear
    echo "error: terminal not high enough (it must be at least 15 lines high)"; exit 1
  fi
}

#get user input
prompt() {
  local input=""
  case $1 in
    password)
      read -s -p "Enter [sudo] password: " input; echo $input
      ;;
    string)
      read -p "Enter string: " input; echo $input
      ;;
    *)
      read -n 1 -p "Enter number to select an option: " input
      if [[ $input =~ ^[1-9]+$ ]]; then echo $input; fi
      ;;
  esac
}

#get sudo
makemeasandwich()
{
  while true; do
    if $(sudo -n true 2>/dev/null); then
      return 0
    else
      header
      content "With great power comes great responsibility!"
      password=$(prompt password)
      echo "$password" | sudo -S -v 2>/dev/null
      if [ $? -ne 0 ]; then
        header
        echo "Wrong password. Try again."; sleep 1
        continue
      fi
    fi
  done
}

#print results of system checks
status() {
  pass
}


## run main loop
while true; do
  # Main menu
  header
  content "1) System status" \
          "2) Configuration" \
          "3) Maintenance" \
          "" \
          "4) Reboot" \
          "5) Shutdown" \
          "6) Exit to shell"
  case $(prompt) in
    1)
      header
      echo "Not yet implemented"; sleep 1
      ;;
    2)
      while true; do
        # Configuration submenu
        header
        content "1) Users" \
                "2) Install admin utilities" \
                "" \
                "*) Return to main menu"
        case $(prompt) in
          1)
            header
            echo "Not yet implemented"; sleep 1
            ;;
          2)
            header
            echo "Not yet implemented"; sleep 1
            ;;
          *)
            break
            ;;
        esac
      done
      ;;
    3)
      while true; do
        # Maintenance submenu
        header
        content "1) System updates" \
                "2) Backup" \
                "3) Update this script" \
                "" \
                "*) Return to main menu"
        case $(prompt) in
          1)
            #update system packages
            makemeasandwich
            if [ $? -eq 0 ]; then
              clear; header; sudo apt update && sudo apt dist-upgrade -y && sudo apt autoremove -y && sudo apt autoclean -y
              clear; header; echo "System is up-to-date"; sleep 1
            fi
            ;;
          2)
            header
            echo "Not yet implemented"; sleep 1
            ;;
          3)
            # Update this script submenu
            header
            #TODO: check for new version
            if false; then #this should run the check
              content "A new version of sconfig is available." \
                      "Do you want to update?" \
                      "" \
                      "1) Yes" \
                      "2) No"
              if [ $(prompt) -eq 1 ]; then
                  #run self update
                  header
                  echo "Update not yet implemented"; sleep 1
              fi
            else
              header
              echo "You are already up-to-date."; sleep 1
            fi
            ;;
          *)
            break
            ;;
        esac
      done
      ;;
    4)
      # Reboot submenu
      header
      content "1) Yes, i really want to reboot." \
              "*) Get me out of here!"
      case $(prompt) in
        1)
          #reboot server
          makemeasandwich
          if [ $? -eq 0 ]; then
            header
            echo "Rebooting server"; sleep 1
            sudo shutdown -r now
          fi
          ;;
        *)
          continue
          ;;
      esac
      ;;
    5)
      # Shutdown submenu
      header
      content "1) Yes, i really want to shutdown." \
              "*) Get me out of here!"
      case $(prompt) in
        1)
          #shutdown server
          makemeasandwich
          if [ $? -eq 0 ]; then
            header
            echo "Shutting down server"; sleep 1
            sudo shutdown -h now
          fi
          ;;
        *)
          continue
          ;;
      esac
      ;;
    6)
      clear; exit 0
      ;;
  esac

done

# **** end of script ****
exit 0