#!/usr/bin/env bash

# How many seconds to sleep before starting the server again, unless it is explicitly specified
DEFAULT_SLEEP_SECONDS=3

declare -A DEV
DEV[option]="dev"
DEV[screen]="steptech"
DEV[dir]=".."

# Which paper servers can be started with this script
SERVERS=( DEV )

# Which configuration to apply to the paper servers
CONFIG="proxy" # Velocity

function show_help {
  local cmd=$0

  echo "Create a start loop for the proxy server and optionally start a number of paper servers with it"
  echo ""
  echo "Usage: $cmd [OPTIONS]"
  echo ""
  echo "OPTIONS:"
  {
    local fmt="  %s\t%s\t%s\n"

    printf "$fmt" "-s" "--sleep" "How many seconds to sleep after stopping the server"
    printf "$fmt" "-n" "--no-loop" "Don't restart the proxy server once it stopped"

    for server_name in "${SERVERS[@]}"; do
      declare -n server="$server_name"
      printf "$fmt" "" "--${server[option]}" "Start the ${server[screen]} server (${server[dir]})"
    done

    printf "$fmt" "-h" "--help" "Show this message"
  } | column -t -s $'\t'

  exit
}

function main {

  local sleep_seconds=$DEFAULT_SLEEP_SECONDS
  local help=false
  local loop=true
  local servers=()

  # Parse arguments
  local cmd=$0
  while [[ $# -gt 0 ]]; do
    local arg=$1
    case "$arg" in
      "--sleep" | "-s")
        sleep_seconds=$2
        shift 2
        ;;
      "--no-loop" | "-n")
        loop=false
        shift
        ;;
      "--help" | "-h")
        help=true
        shift
        ;;
      *)
        local option_found=false
        for server_name in "${SERVERS[@]}"; do
          declare -n server="$server_name"
          if [ "$arg" = "--${server[option]}" ]; then
            servers+=("$server_name")
            option_found=true
          fi
        done

        if ! $option_found; then
          err "Unknown argument: $arg"
        fi
        shift
        ;;
    esac
  done

  if $help; then
    show_help "$cmd"
  fi

  # Start servers
  for server_name in "${servers[@]}"; do
    declare -n server="$server_name"
    # Create server screen if it doesn't exist yet
    local screen="${server[screen]}"
    screen -ls | grep -q "$screen" || screen -dmS "$screen"
    # Start the server
    screen -S "$screen" -X stuff "cd $(pwd)/${server[dir]}; ./start.sh --no-loop --config \"$CONFIG\" --tmp\n"
    echo "Started paper server in screen $screen"
  done

  function cleanup {
    for server_name in "${servers[@]}"; do
      declare -n server="$server_name"
      local screen="${server[screen]}"
      screen -S "$screen" -X stuff "stop\n"
      echo "Stopped paper server in screen $screen"
    done

    exit
  }

  trap cleanup SIGINT

  while :; do
    echo "Starting proxy..."
    ./launch.sh

    $loop || break

    echo "Sleeping for $sleep_seconds seconds..."
    sleep "$sleep_seconds"
  done

  cleanup
}

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

main "$@"