#!/usr/bin/env bash

# THe name of the screen in which the proxy server will run
PROXY_SCREEN="proxy"
# How many seconds to sleep before starting the server again, unless it is explicitly specified
DEFAULT_SLEEP_SECONDS=3

function main {
  local proxy=false
  local bungee=false
  local help=false
  local sleep_seconds=$DEFAULT_SLEEP_SECONDS
  local config=""

  local cmd=$0

  # TODO --config is incompatible with --proxy, --bungee and standalone
  while [ $# -gt 0 ]; do
    local arg=$1
    case "$arg" in
      "--config" | "-c")
        config=$2 #TODO ensure mode is valid
        shift 2
        ;;
      "--sleep" | "-s")
        sleep_seconds=$2
        shift 2
        ;;
      "--proxy")
        proxy=true
        if $bungee; then
          err "--proxy can't be used together with --bungee"
        fi
        shift
        ;;
      "--bungee")
        bungee=true
        if $proxy; then
          err "--bungee can't be used together with --proxy"
        fi
        shift
        ;;
      "--help" | "-h")
        help=true
        shift
        ;;
      *)
        err "Unknown argument: $arg"
        ;;
    esac
  done

  if $help; then
    echo "Create a start loop for the minecraft server, additionally behind a velocity proxy or bungeecord proxy"
    echo ""
    echo "Usage $cmd [OPTIONS]"
    echo ""
    echo "OPTIONS:"
    echo "  -c --config <mode>  How to configure the server. Possible values for mode are: proxy, bungee, standalone"
    echo "  -s --sleep <secs>   How many seconds to sleep after the server has stopped before starting it again"
    echo "  -h --help           Show help"
    echo "     --proxy          Start the server behind a velocity proxy"
    echo "     --bungee         Start the server behind a bungeecord proxy"
    exit
  fi

  # TODO perform configuration according to config parameter

  if $proxy; then
    ./configure.sh velocity

    # create proxy screen if it doesn't exist yet
    screen -ls | grep -q "$PROXY_SCREEN" || screen -dmS "$PROXY_SCREEN"
    # start the proxy
    screen -S "$PROXY_SCREEN" -X stuff "cd $(pwd)/proxy; ./launch.sh\n"

    echo "The velocity proxy has been started in the screen '$PROXY_SCREEN'"
  elif $bungee; then
    ./configure.sh bungeecord

    # create proxy screen if it doesn't exist yet
    screen -ls | grep -q "$PROXY_SCREEN" || screen -dmS "$PROXY_SCREEN"
    # start the proxy
    screen -S "$PROXY_SCREEN" -X stuff "cd $(pwd)/bungee; ./launch.sh\n"

    echo "The bungeecord proxy has been started in the screen '$PROXY_SCREEN'"
  else
    ./configure.sh standalone
  fi

  trap cleanup SIGINT

  cleanup() {
    if $proxy || $bungee; then
      # stop the proxy
      screen -S "$PROXY_SCREEN" -X stuff "end\n"
      echo "The proxy has been stopped"
    fi

    exit
  }

  while true
  do
    echo starting server...
    ./launch.sh
    echo sleeping...
    sleep "$sleep_seconds"
  done
}

# Shows ans error message and exits the program with code 1
#
# Usage: err <msg>
function err {
  echo "$1"
  exit 1
}

main "$@"