#!/bin/sh

#                                     ╭───────────────╮
#                                     │ env functions │
#                                     ╰───────────────╯
# ───────────────────────────────────< ANSI color codes >───────────────────────────────────
RED='\033[0;31m'
CYAN='\033[0;36m'
YELLOW='\033[0;33m'
LIGHT_GREEN='\033[0;92m'
BOLD='\033[1m'
NC='\033[0m' # No Color

echo_error() {
  printf "${BOLD}${RED}ERROR: ${NC}${RED}%s${NC}\n" "$1" >&2
}

echo_info() {
  printf "${BOLD}${CYAN}INFO: ${NC}${CYAN}%s${NC}\n" "$1"
}

echo_warning() {
  printf "${BOLD}${YELLOW}WARNING: ${NC}${YELLOW}%s${NC}\n" "$1"
}

echo_note() {
  printf "${BOLD}${LIGHT_GREEN}NOTE: ${NC}${LIGHT_GREEN}%s${NC}\n" "$1"
}

command_exists() {
  command -v "$@" >/dev/null 2>&1
}

# ─────────────< Check if the user is root and set sudo variable if necessary >─────────────
check_root() {
  if [ "$(id -u)" -ne 0 ]; then
    if command_exists sudo; then
      echo_info "User is not root. Using sudo for privileged operations."
      _sudo="sudo"
    else
      echo_error "No sudo found and you're not root! Can't install packages."
      return 1
    fi
  else
    echo_info "Root access confirmed."
    _sudo=""
  fi
}

# ──────────────────────< Check if the given command exists silently >──────────────────────
command_exists() {
  command -v "$@" >/dev/null 2>&1
}

#                          ╭────────────────────────────────────╮
#                          │ insert your scripts/functions here │
#                          ╰────────────────────────────────────╯

full_update_and_upgrade() {
  if command_exists apt-get; then
    echo_info "Updating sources.."
    $_sudo apt-get update || echo_error "Something went wrong, please check your connection and permissions!"
    $_sudo apt-get upgrade --assume-yes || echo_error "Something went wrong, please check your connection and permissions!"
    $_sudo apt-get full-upgrade --assume-yes || echo_error "Something went wrong, please check your connection and permissions!"
  else
    echo_error "The OS is not suitable for this script!"
  fi
}

clean_and_full_upgrade() {
  if command_exists apt-get; then
    echo_info "Cleaning the environment.."
    $_sudo apt-get clean --assume-yes
    full_update_and_upgrade
  else
    echo_error "The OS is not suitable for this script!"
  fi
}

post_clean() {
  if command_exists apt-get; then
    $_sudo apt-get autoremove --assume-yes
  else
    echo_error "The OS is not suitable for this script!"
  fi
}

detect_version() {
  . /etc/os-release
  case "$VERSION_CODENAME" in
  bookworm)
    cur_os="bookworm"
    tar_os="trixie"
    ;;
  buster)
    cur_os="buster"
    tar_os="bullseye"
    ;;
  bullseye)
    cur_os="bullseye"
    tar_os="bookworm"
    ;;
  *)
    echo_error "$VERSION_CODENAME is either not a debian version, or just simply not defined"
    return 1
    ;;
  esac
}

update_sources() {
  # Create backup directory if it doesn't exist
  BACKUP_DIR="/var/backups/apt-sources"
  echo_info "Creating backup directory at $BACKUP_DIR..."
  $_sudo mkdir -p "$BACKUP_DIR"

  echo_info "Backing up current sources lists..."
  $_sudo cp /etc/apt/sources.list "$BACKUP_DIR/sources.list.backup.$(date +%Y%m%d)"

  echo_info "Updating sources from Bookworm to Trixie..."
  # Replace bookworm with trixie in main sources.list
  $_sudo sed -i "s/$cur_os/$tar_os/g" /etc/apt/sources.list

  # Check and update any additional source files in sources.list.d
  if [ -d "/etc/apt/sources.list.d" ]; then
    for sourcefile in /etc/apt/sources.list.d/*.list; do
      if [ -f "$sourcefile" ]; then
        filename=$(basename "$sourcefile")
        echo_info "Backing up and updating $sourcefile..."
        $_sudo cp "$sourcefile" "$BACKUP_DIR/${filename}.backup.$(date +%Y%m%d)"
        $_sudo sed -i "s/$cur_os/$tar_os/g" "$sourcefile"
      fi
    done
  fi

  echo_note "Sources have been updated to Trixie. Please run a full system update."
  echo_warning "Make sure to review the changes and ensure all repositories are compatible with Trixie!"
  echo_info "Backups stored in $BACKUP_DIR"
  echo ""
  __lsb_release__="$(lsb_release -a)"
  echo_info "$__lsb_release__"
}

# ───────────────────────────────< main function to execute >───────────────────────────────
main() {
  if check_root; then
    full_update_and_upgrade
    if detect_version; then
      update_sources
    fi
    clean_and_full_upgrade
    post_clean
  else
    echo_error "Something went terribly wrong!"
  fi
}

main