#!/bin/zsh
while [[ "$#" -gt 0 ]]
do 
  case $1 in
    --app_name) app_name="$2"
    shift;;
    --id) desired_id="$2"
    shift;;
    *) echo "Unknown parameter passed: $1"
    exit 1;;
  esac
  shift
done

# Validate desired_id is a number
if ! [[ "$desired_id" =~ ^[0-9]+$ ]]; then
  echo "Error: Invalid UID/GID. Please enter a numeric value."
  exit 1
fi

user_name="${app_name}-user"
group_name="${app_name}-group"

echo "--- Checking/Creating User and Group for ${app_name} ---"

# --- Handle Group ---
echo "Checking group: ${group_name}"
existing_gid=$(getent group "${group_name}" | cut -d: -f3)

if [[ -n "$existing_gid" ]]; then
  if [[ "$existing_gid" -eq "$desired_id" ]]; then
    echo "Group '${group_name}' already exists with the correct GID (${desired_id})."
  else
    echo "Group '${group_name}' exists with GID ${existing_gid}, but desired GID is ${desired_id}."
    echo "Attempting to modify group GID..."
    if sudo groupmod -g "$desired_id" "${group_name}"; then
      echo "Successfully adjusted group '${group_name}' to GID ${desired_id}."
    else
      echo "Failed to adjust group '${group_name}' GID. Please check permissions or try manually."
      exit 1
    fi
  fi
else
  echo "Group '${group_name}' does not exist. Creating..."
  if sudo groupadd -g "$desired_id" "${group_name}"; then
    echo "Successfully created group '${group_name}' with GID ${desired_id}."
  else
    echo "Failed to create group '${group_name}'. Please check permissions or try manually."
    exit 1
  fi
fi

# --- Handle User ---
echo "Checking user: ${user_name}"
existing_uid=$(getent passwd "${user_name}" | cut -d: -f3)

if [[ -n "$existing_uid" ]]; then
  if [[ "$existing_uid" -eq "$desired_id" ]]; then
    echo "User '${user_name}' already exists with the correct UID (${desired_id})."
  else
    echo "User '${user_name}' exists with UID ${existing_uid}, but desired UID is ${desired_id}."
    echo "Attempting to modify user UID..."
    if sudo usermod -u "$desired_id" -g "$desired_id" "${user_name}"; then
      echo "Successfully adjusted user '${user_name}' to UID ${desired_id} and primary GID ${desired_id}."
    else
      echo "Failed to adjust user '${user_name}' UID/GID. Please check permissions or try manually."
      exit 1
    fi
  fi
else
  echo "User '${user_name}' does not exist. Creating..."
  if sudo useradd -u "$desired_id" -g "$desired_id" -s /sbin/nologin -c "Application User for ${app_name}" "${user_name}"; then
    echo "Successfully created user '${user_name}' with UID ${desired_id} and primary GID ${desired_id}."
  else
    echo "Failed to create user '${user_name}'. Please check permissions or try manually."
    exit 1
  fi
fi

echo "--- Operation complete for ${app_name} ---"