#!/usr/sbin/env bash
# Disables warning about echo not expanding escape sequences
# shellcheck disable=SC2028

# Used for internal errors
function internal_error() {
  echo "-> INTERNAL ERROR: ${*}"
  exit 99
}

# Automatically accepts the End User License Agreement
function accept_eula() {
  echo "eula=true" > /data/eula.txt
}

# Cleans /logs and /crash-reports
function clean_logs() {
  if [ "${MCSD_CLEAN_LOGS}" == "true" ]; then
    rm -rf "/data/logs" "/data/crash-reports"
  fi
}

# Used by trap, shuts the server down
function kill_server() {
  if [ -z "${CHILDPID}" ]; then
    internal_error "\$CHILDPID is unset"
  fi
  export "SHUTDOWN=true"
  kill -INT "${CHILDPID}"
}

# Print the MCSD banner
function print_banner() {
  echo "         ____     ____                                          ____                    __"
  echo " /'\\_/\`\\/\\  _\`\\  /\\  _\`\\                                       /\\  _\`\\                 /\\ \\"
  echo "/\\      \\ \\ \\/\\_\\\\ \\,\\L\\_\\     __   _ __   __  __     __   _ __\\ \\ \\/\\ \\    ___     ___\\ \\ \\/'\\      __   _ __"
  echo "\\ \\ \\__\\ \\ \\ \\/_/_\\/_\\__ \\   /'__\`\\/\\\`'__\\/\\ \\/\\ \\  /'__\`\\/\\\`'__\\ \\ \\ \\ \\  / __\`\\  /'___\\ \\ , <    /'__\`\\/\\\`'__\\"
  echo " \\ \\ \\_/\\ \\ \\ \\L\\ \\ /\\ \\L\\ \\/\\  __/\\ \\ \\/ \\ \\ \\_/ |/\\  __/\\ \\ \\/ \\ \\ \\_\\ \\/\\ \\L\\ \\/\\ \\__/\\ \\ \\\\\`\\ /\\  __/\\ \\ \\/"
  echo "  \\ \\_\\\\ \\_\\ \\____/ \\ \`\\____\\ \\____\\\\ \\_\\  \\ \\___/ \\ \\____\\\\ \\_\\  \\ \\____/\\ \\____/\\ \\____\\\\ \\_\\ \\_\\ \\____\\\\ \\_\\"
  echo "   \\/_/ \\/_/\\/___/   \\/_____/\\/____/ \\/_/   \\/__/   \\/____/ \\/_/   \\/___/  \\/___/  \\/____/ \\/_/\\/_/\\/____/ \\/_/"
}

# Initialize MCSD
function initialize() {
  echo ":: Initializing MCSD"
  # Server arguments
  if [ ! "${MCSD_ENFORCE_FRESH_CACHES}" == "true" ] && [ ! "${MCSD_ENFORCE_FRESH_CACHES}" == "false" ]; then
    echo ":: Warning: No/Invalid value supplied to \$MCSD_ENFORCE_FRESH_CACHES, defaulting to false"
    export "MCSD_ENFORCE_FRESH_CACHES=false"
  fi
  if [ ! "${MCSD_FORCE_UPGRADE}" == "true" ] && [ ! "${MCSD_FORCE_UPGRADE}" == "false" ]; then
    echo ":: Warning: No/Invalid value supplied to \$MCSD_FORCE_UPGRADE, defaulting to true"
    export "MCSD_FORCE_UPGRADE=true"
  fi
  if [ ! "${MCSD_SAFEMODE}" == "true" ] && [ ! "${MCSD_SAFEMODE}" == "false" ]; then
    echo ":: Warning: No/Invalid value supplied to \$MCSD_SAFEMODE, defaulting to false"
    export "MCSD_SAFEMODE=false"
  fi
  # MCSD functionality
  if [ ! "${MCSD_CLEAN_LOGS}" == "true" ] && [ ! "${MCSD_CLEAN_LOGS}" == "false" ]; then
    echo ":: Warning: No/Invalid value supplied to \$MCSD_CLEAN_LOGS, defaulting to false"
    export "MCSD_CLEAN_LOGS=false"
  fi
  # Memory limits
  if [ -z "${MCSD_MEMORY_MIN}" ]; then
    echo ":: Error: No memory limit supplied to \$MCSD_MEMORY_MIN"
    exit 1
  fi
  if [ -z "${MCSD_MEMORY_MAX}" ]; then
    echo ":: Error: No memory limit supplied to \$MCSD_MEMORY_MAX"
    exit 1
  fi
  # Java version
  if [ ! "${MCSD_JAVA_VERSION}" == "17" ] && [ ! "${MCSD_JAVA_VERSION}" == "11" ] && [ ! "${MCSD_JAVA_VERSION}" == "8" ]; then
    echo ":: Warning: No/Invalid java version supplied to \$MCSD_JAVA_VERSION, defaulting to java version 17"
    export "MCSD_JAVA_VERSION=17"
  fi
  # Java optimization
  if [ ! "${MCSD_OPTIMIZED_FLAGS}" == "true" ] && [ ! "${MCSD_OPTIMIZED_FLAGS}" == "false" ]; then
    echo ":: Warning: No/Invalid value supplied to \$MCSD_OPTIMIZED_FLAGS, defaulting to true"
    export "MCSD_OPTIMIZED_FLAGS=true"
  fi
  if [ ! "${MCSD_GARBAGECOLLECTOR}" == "G1GC" ] && [ ! "${MCSD_GARBAGECOLLECTOR}" == "ZGC" ]; then
    echo ":: Warning: No/Invalid value supplied to \$MCSD_GARBAGECOLLECTOR, defaulting to G1GC"
    export "MCSD_GARBAGECOLLECTOR=G1GC"
  fi
}

# Check for directories and files
function check() {
  echo ":: Checking environment"
  if [ ! -d "/data" ]; then
    echo ":: Error: Could not locate /data directory"
    exit 1
  fi
  if [ ! -f "/data/server.jar" ]; then
    echo ":: Error: Could not locate server.jar"
    exit 1
  fi
}

# Compile server arguments
function compile_args() {
  echo ":: Compiling server arguments"
  export "ARGS=--nogui"
  case "${MCSD_ENFORCE_FRESH_CACHES}" in
    "true")
      export "ARGS=${ARGS} --eraseCache"
      ;;
    "false") ;;
    *)
      internal_error "\$MCSD_ENFORCE_FRESH_CACHES has invalid value"
      ;;
  esac
  case "${MCSD_FORCE_UPGRADE}" in
    "true")
      export "ARGS=${ARGS} --forceUpgrade"
      ;;
    "false") ;;
    *)
      internal_error "\$MCSD_FORCE_UPGRADE has invalid value"
      ;;
  esac
  case "${MCSD_SAFEMODE}" in
    "true")
      export "ARGS=${ARGS} --safeMode"
      ;;
    "false") ;;
    *)
      internal_error "\$MCSD_SAFEMODE has invalid value"
      ;;
  esac
}

# Compile java flags
function compile_flags() {
  echo ":: Compiling java flags"
  export "FLAGS=-Xms${MCSD_MEMORY_MIN} -Xmx${MCSD_MEMORY_MAX}"
  case "${MCSD_OPTIMIZED_FLAGS}" in
    "true")
      export "FLAGS=${FLAGS} -XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+AlwaysActAsServerClassMachine -XX:+AlwaysPreTouch -XX:+DisableExplicitGC -XX:+UseNUMA -XX:NmethodSweepActivity=1 -XX:ReservedCodeCacheSize=400M -XX:NonNMethodCodeHeapSize=12M -XX:ProfiledCodeHeapSize=194M -XX:NonProfiledCodeHeapSize=194M -XX:-DontCompileHugeMethods -XX:MaxNodeLimit=240000 -XX:NodeLimitFudgeFactor=8000 -XX:+UseVectorCmov -XX:+PerfDisableSharedMem -XX:+UseFastUnorderedTimeStamps -XX:+UseCriticalJavaThreadPriority -XX:ThreadPriorityPolicy=1 -XX:AllocatePrefetchStyle=3"
      ;;
    "false") ;;
    *)
      internal_error "\$MCSD_OPTIMIZED_FLAGS has invalid value"
      ;;
  esac
  case "${MCSD_GARBAGECOLLECTOR}" in
    "G1GC")
      export "FLAGS=${FLAGS} -XX:+UseG1GC -XX:MaxGCPauseMillis=130 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=28 -XX:G1HeapRegionSize=16M -XX:G1ReservePercent=20 -XX:G1MixedGCCountTarget=3 -XX:InitiatingHeapOccupancyPercent=10 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=0 -XX:SurvivorRatio=32 -XX:MaxTenuringThreshold=1 -XX:G1SATBBufferEnqueueingThresholdPercent=30 -XX:G1ConcMarkStepDurationMillis=5 -XX:G1ConcRSHotCardLimit=16 -XX:G1ConcRefinementServiceIntervalMillis=150"
      ;;
    "ZGC")
      export "FLAGS=${FLAGS} -XX:+UseZGC -XX:AllocatePrefetchStyle=1 -XX:-ZProactive"
      ;;
    *)
      internal_error "\$MCSD_GARBAGECOLLECTOR has invalid value"
      ;;
  esac
}

print_banner
initialize
check
accept_eula
clean_logs
compile_args
compile_flags

echo ":: Starting server"
cd /data||exit 69
exec "/usr/lib/jvm/java-${MCSD_JAVA_VERSION}-openjdk/bin/java" ${FLAGS} -jar "/data/server.jar" ${ARGS}