Dayz Linux Script to download Mods and Launch game

#!/bin/bash

#####################################################################################################################################################################
#
# Script helps installing mods for connecting to a modded Dayz server (as dayz launcher does not yet work in proton).
#
# I used dayz-linux-cli-launcher and dayz-dztui as examples to combine and change what I understand and need as
# both were not running completely for me. To understand what's wrong I need to do it for myself from scratch.
# So, credits to both the authors for the great work!
#
# Script reads what mods the given server needs and downloads them via steamcmd.
# Mods are downloaded into the Steam-workshop-dayz (221100) directory. After that symlinks will be created
# from these workshop mods into the Dayz directory (starting with @ followed by the mod-ID).
# From all the mod-IDs a string is concatenated to be given to the launch command (-mod="@...;@...;").
# Then the script tries to connect to the dayz server using these mods (Steam application must be running for this).
#
# I normally get the server ip:port from web pages listing servers. If the steam query port is not 27016 and not mentioned,
# then I do not know how to get it. This port is needed for the API to retrieve the server information.
# In that case I normally try another server until I get a positive response.
#
# Start the script with e.g.:
# ./dayz-mod-launcher.sh \
#  --server <ip>:<gameport> \
#  --port 27016 \
#  --mods \
#  --launch \
#  --name jahan
#
# Or in a shorter command:
# ./dayz-mod-launcher.sh -s <ip>:<gameport> -m -l -n <profilename>
#
# I put this in an additional script, like dayz_servername.sh to be able to connect to different servers.
# So for every server you create a own file with the right ip:port.
#
# If all mods are downloaded for server, I edit this script and delete the line for updating the mods (--mods).
# That way it does not take so long to connect to the server.
# Also 2 scripts can be created, one for launching and one for updating the mods.
# 1) ./dayz-mod-launcher.sh --server <ip>:<port> --port 27016 --mods
# 2) ./dayz-mod-launcher.sh --server <ip>:<port> --port 27016 --launch --name jahan
# (add -d for more output=
#
# The script does not check everything possible and error out. I just wanted to create a short, intuitive solution
# which does the job automatically for me as simple as possible.
#
# In Steam add proton_experimental in the compability tab of the Dayz Properties.
# I have the following launch options set on the General tab (DXVK_FRAME_RATE to cap my fps):
# DXVK_FRAME_RATE=60 %command% -skipintro -nolauncher -nosplash
#
# Issue:
# The very first time all mods where downloaded for a server and I tried to connect, it worked but I had only 1-2fps and the game crashed soon.
# So go to Steam and start Dayz (seöect Run Dayz Client). In the options (Video) menu deactivate vertical sync.
# After that I was able to play on the modded server and everything worked fine.
#
# I do not know why but sometimes steamcmd stays here for long before it starts to validate the mods:
#   Connecting anonymously to Steam Public...OK
#   Waiting for client config...OK
#   Waiting for user info...OK
# I think it's related to Steam. At other times of the day (in the morning) it works very much faster.
#
# It takes a bit to download the mods. If there is a Timeout in steamcmd I copy the last mod-ID and use this page (add the mod-id at the end of the URL)...
#    https://steamcommunity.com/sharedfiles/filedetails/?id=
# ...to get the name of the mod to download it directly in the Steam workshop of Dayz (Steam-UI).
# This happens often for the larger mods (>2-3+ GB). You can also try to run the script again....sometimes it finishes downloading.
#
#####################################################################################################################################################################
# Edit/change config options below to your needs.

#----------------------------------------------------------------------------------

#BEGIN CONFIG===============
# Steam Dayz application ID (no need to change)
DAYZ_ID=221100
# path to the Steam directory
STEAM_PATH="/home/jahan/.local/share/Steam/"
# path from the Steam directory to the Dayz game directory
GAME_DIR="$STEAM_PATH/steamapps/common/DayZ"
# path from the Steam directory to the workshop directory
WORKSHOP_DIR="$STEAM_PATH/steamapps/workshop/content"
# Dayz ingame name/profile
INGAMENAME="jahan"
#END CONFIG=================

#STEAMCMD CONFIG============
# user which runs the steamcmd application
STEAMCMD_USER="jahan"
# username for steamcmd, anonymous can be used or your real steam user
STEAMCMD_USERNAME="anonymous"
#END STEAMCMD CONFIG========

#----------------------------------------------------------------------------------
# Only change anything below if something is not working for you or you want to adapt something

set -eo pipefail
SELF=$(basename "$(readlink -f "${0}")")

# program dependencies
deps=("jq" "steamcmd" "curl" "sed" "steam")

# DZSA Launcher API (to query server data)
API_URL="https://dayzsalauncher.com/api/v1/query/@ADDRESS@/@PORT@"
API_PARAMS=(
  -sSL
  -m 10
  -H "User-Agent: dayz-linux-cli-launcher"
)

DEBUG=0
LAUNCH=0
SERVER=""
PORT="27016"
DLMODS=0
NAME=""

print_help() {
  cat <<EOF
Usage: ${SELF} [OPTION]... [MODID]... [-- [GAME-PARAM]...]

For a given Dayz server:port the script automatically set up mods,
launch the game and connect to a server.

Command line options:

  -h
  --help
    Print this help text.

  -d
  --debug
    Print debug messages to output (more text).

  -s <address[:port]>
  --server <address[:port]>
    Server ip and game port (e.g. from game server listings)
    Needs to be provided...otherwise the script cannot do anything.
    This will query the servers mod list and prints out information.
    Can be used (without --mods / --launch) just to get these information.
    If --mods is set, it will automatically download mods.
    If --launch is set, Dayz will automatically connect to the server/port.

  -m
  --mods
    Download or updates mods automatically via steamcmd.
    Also creates sysmlinks of the workshop mods into the Dayz game directory.
    If mods are up-to-date, this can be left out (to start the game via --launch faster).
    If there are pbo issues connecting to the game, include it again to validate the mods.

  -l
  --launch
    Launch DayZ and connect to given server.
    Steam needs to be open.

  -n <name>
  --name <name>
    Set the profile name when launching the game via --launch.
    Some community servers require a profile name when trying to connect.

  -p <port>
  --port <port>
    The server's query port, not to be confused with the server's game port.
    If option is not used, the default value will be used: 27016
    Needed to query mod information from the server.

EOF
}

while (( "$#" )); do
  case "${1}" in
    -h|--help)
      print_help
      exit
      ;;
    -d|--debug)
      DEBUG=1
      ;;
    -m|--mods)
      DLMODS=1
     ;;
    -l|--launch)
      LAUNCH=1
      ;;
    -s|--server)
      SERVER="${2}"
      shift
      ;;
    -p|--port)
      PORT="${2}"
      shift
      ;;
    -n|--name)
      INGAMENAME="${2}"
      shift
      ;;
  esac
  shift
done


depcheck(){
  for dep in "${deps[@]}"; do
    command -v $dep 2>&1>/dev/null || (printf "[ERROR] Program $dep is missing but required. Please install.\n" ; exit 1)
  done
}

msg() {
  echo -e "[${SELF}][info] ${@}"
}

err() {
  echo -e >&2 "[${SELF}][error] ${@}"
  exit 1
}

debug() {
  if [[ ${DEBUG} == 1 ]]; then
    echo -e "[${SELF}][debug] ${@}"
  fi
}

check_dir() {
  debug "Checking directory: ${1} - ${2}"
  [[ -d "${1}" ]] || err "Invalid/missing directory: ${1}"
}

query_server_api() {
  [[ -z "${SERVER}" ]] && return
  local query
  local response
  msg "Querying API for server: ${SERVER%:*}:${PORT}"
  query="$(sed -e "s/@ADDRESS@/${SERVER%:*}/" -e "s/@PORT@/${PORT}/" <<< "${API_URL}")"
  debug "Querying ${query}"
  response="$(curl "${API_PARAMS[@]}" "${query}")"
  debug $response"\n"
  msg "Parsing API response...\n"
  jq -e ".result.mods[]" >/dev/null 2>&1 <<< "${response}" || err "Missing mods data from API response"

  SERVERNAME=$(jq -r ".result.name" <<< "${response}")
  msg "Servername:\n"$SERVERNAME"\n"

  MODNAMES=$(jq ".result.mods[].name" <<< "${response}")
  MODIDS=$(jq ".result.mods[].steamWorkshopId" <<< "${response}")
  msg "Anzahl Mods: "$(echo $MODIDS | wc -w)"\n"
  debug "Modnames:\n"$MODNAMES"\n"
  debug "ModIds:\n"$MODIDS"\n"
}

# create a mod list which can be given to steamcmd to download each of them
steamcmd_modlist(){
  for i in $MODIDS; do
    printf "+workshop_download_item %s %s " $DAYZ_ID $i
  done
}

# download mods to the Steam workshop dir
auto_download_mods() {
  msg "Downloading mods via steamcmd...\n"
  sudo su -c "steamcmd +force_install_dir $STEAM_PATH +login $STEAMCMD_USERNAME $(steamcmd_modlist) validate +quit" $STEAMCMD_USER
  printf "\n"
}

# create symlinks of the Workshop mods into the Steam Dayz directory (mod IDs as names)
symlinks(){
  printf "\n"
  msg "Creating symlinks for new mods...\n"
  for i in $MODIDS; do
  # create symlink from mods in Steam/steamapps/workshop/DAYZ-ID folder in the Steam/steamapps/common/DAYZ folder (starting with @)
  ln -fs "$WORKSHOP_DIR/$DAYZ_ID/$i" "$GAME_DIR/@$i"
#  MODS=$MODS"@"$i";"
  done
}

buildmodstring(){
  # build mod string to be given to the launch command -mod= parameter
  for i in $MODIDS; do
  MODS=$MODS"@"$i";"
  done
  debug "Mod String to launch game (-mod= parameter): "
  debug $MODS"\n"
}

main () {

  clear

  msg "Checking a few program dependencies..."
  depcheck
  msg "Ok."

  if [[ -z "$SERVER" ]]; then
    msg "Nothing to do..."
    msg "No --server address set. This is a mandatory option to continue-"
    msg "See --help for all the available options."
    exit
  fi

  msg "Start of Dayz-Mod-Launcher-Script...\n"

  debug "Checking directories..."
  check_dir "${STEAM_PATH}"  "STEAM_PATH"
  check_dir "${GAME_DIR}" "GAME_DIR"
  check_dir "${WORKSHOP_DIR}" "WORKSHOP_DIR"
  debug "Directories ok.\n"

  # query mod-information from server
  query_server_api
  buildmodstring

  if [[ "${DLMODS}" == 1 ]]; then
    # download or update mods
    # comment out if all mods are downloaded already
    auto_download_mods

    # create symlinks in the game dir for each mod
    # comment out if all mods are downloaded and links are already installed
    symlinks
  fi

  if [[ "${LAUNCH}" == 1 ]]; then
    msg "Launching DayZ:"
    msg "Trying to connect to server...\n"
    # the next command is needed, otherwise the game crashes or causes a black screen (see protondb dayz comments)
    sudo sysctl -w vm.max_map_count=16777216
    debug "steam -applaunch $DAYZ_ID -connect=$SERVER -nolauncher -skipintro -nosplash -world=empty -name=$INGAMENAME -mod="\"$MODS\""\n"
    # connect to the server via steam applaunch
    steam -applaunch $DAYZ_ID -connect=$SERVER -nolauncher -skipintro -nosplash -world=empty -name=$INGAMENAME -mod="$MODS"
    msg "Good luck out there in the fields...\n"
  fi

}

main