#!/usr/bin/env bash
# @file ~/.local/bin/add-usergroup
# @brief Add a user and a group with the same name on either Linux or macOS
# @description
#     This script is utilized by other scripts to ensure that there is both a user and group
#     named by the single argument that this executable accepts. It checks whether or not
#     there is already a user / group with the name present on the system before running
#     any code. On macOS, it assigns the user an ID that equal to the maximum user ID present
#     on the system plus one.

# Check if the script is being run as root
if [[ $EUID -ne 0 ]]; then
  if command -v logg > /dev/null; then
    logg error "This script must be run as root"
  else
    echo -e "\e[91mThis script must be run as root\e[0m"
  fi
  exit 1
fi

# Check if the correct number of arguments is provided
if [[ $# -ne 2 ]]; then
  if command -v logg > /dev/null; then
    logg info "Usage: $0 <user> <group>"
  else
    echo -e "\e[93mUsage: $0 <user> <group>\e[0m"
  fi
  exit 1
fi

USER=$1
GROUP=$2

# Check if the operating system is macOS
if [ -d /Applications ] && [ -d /System ]; then
  if command -v logg > /dev/null; then
    logg info "Creating group and user ${GROUP} on macOS..."
  else
    echo -e "\e[96mCreating group and user ${GROUP} on macOS...\e[0m"
  fi

  # Ensure group exists
  if ! dscl . read "/Groups/$GROUP" gid &> /dev/null; then
    MAX_ID_GROUP="$(dscl . -list /Groups gid | awk '{print $2}' | sort -ug | tail -1)"
    PRIMARY_GROUP_ID="$((MAX_ID_GROUP+1))"
    dscl . create "/Groups/$GROUP"
    # This also sets the PrimaryGroupID
    sudo dscl . create "/Groups/$GROUP" gid "$PRIMARY_GROUP_ID"
    sudo dscl . append "/Groups/$GROUP" GroupMembership "$USER"
  else
    PRIMARY_GROUP_ID="$(dscl . read "/Groups/$GROUP" gid | awk '{print $2}')"
  fi

  # Ensure user exists
  if ! dscl . read "/Users/$GROUP" UniqueID &> /dev/null; then
    MAX_ID_USER="$(dscl . -list /Users UniqueID | sort -nr -k 2 | head -1 | grep -oE "[0-9]+$")"
    UNIQUE_ID="$((MAX_ID_USER+1))"
    sudo dscl . create "/Users/$GROUP"
    sudo dscl . create "/Users/$GROUP" UniqueID "$UNIQUE_ID"
    sudo dscl . create "/Users/$GROUP" PrimaryGroupID "$PRIMARY_GROUP_ID"
  else
    UNIQUE_ID="$(dscl . read "/Users/$GROUP" UniqueID | awk '{print $2}')"
  fi

  # Add the user to the group
  sudo dseditgroup -o edit -t user -a "$GROUP" "$GROUP"
  # Add the current user to the group
  sudo dseditgroup -o edit -t user -a "$USER" "$GROUP"
  # Add USER group to the group
  sudo dseditgroup -o edit -t group -a "$USER" "$GROUP"


  if command -v logg > /dev/null; then
    logg info "Group and user ${GROUP} created successfully on macOS"
  else
    echo -e "\e[92mGroup and user ${GROUP} created successfully on macOS\e[0m"
  fi
elif [[ "$(uname)" == "Linux" ]]; then
  if command -v logg > /dev/null; then
    logg info "Creating group and user ${GROUP} on Linux..."
  else
    echo -e "\e[96mCreating group and user ${GROUP} on Linux...\e[0m"
  fi

  # Check if the group already exists
  if ! grep -qE "^${GROUP}:" /etc/group; then
    # Create the group
    groupadd "${GROUP}"
  else
    if command -v logg > /dev/null; then
      logg info "Group ${GROUP} already exists"
    else
      echo -e "\e[93mGroup ${GROUP} already exists\e[0m"
    fi
  fi

  # Check if the user already exists
  if ! id -u "${GROUP}" >/dev/null 2>&1; then
    # Create the user and assign it to the group
    useradd -g "${GROUP}" "${GROUP}"
  else
    if command -v logg > /dev/null; then
      logg info "User ${GROUP} already exists"
    else
      echo -e "\e[93mUser ${GROUP} already exists\e[0m"
    fi
  fi

  if command -v logg > /dev/null; then
    logg success "Group and user ${GROUP} created successfully on Linux"
  else
    echo -e "\e[92mGroup and user ${GROUP} created successfully on Linux\e[0m"
  fi
fi