#!/bin/sh

set -eu

OS="$(uname -s)"

die() {
  printf 'Fehler: %s\n' "$*" >&2
  exit 1
}

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

check_prerequisites() {
  case "$OS" in
  Darwin)
    if ! have brew; then
      die "Homebrew ist nicht installiert."
    fi
    ;;
  FreeBSD)
    if ! have doas; then
      die "doas ist nicht installiert."
    fi
    ;;
  *)
    die "Nicht unterstütztes Betriebssystem: $OS"
    ;;
  esac
}

setup_homebrew_env() {
  case "$OS" in
  Darwin)
    export HOMEBREW_NO_AUTO_UPDATE=1
    export HOMEBREW_NO_INSTALL_CLEANUP=1
    ;;
  esac
}

install_pkg() {
  binary="$1"
  package="$2"

  if have "$binary"; then
    printf "✓ %-32s vorhanden\n" "$binary"
    return
  fi

  printf "→ Installiere %s\n" "$package"

  case "$OS" in
  Darwin)
    brew install "$package"
    ;;
  FreeBSD)
    doas pkg install -y "$package"
    ;;
  esac
}

install_prerequisites() {
  install_pkg zsh zsh
}

install_plugin() {
  # zsh-syntax-highlighting/zsh-autosuggestions haben kein eigenes Binary,
  # deshalb Pruefung anhand des von zsh/zshrc gesourceten Pfads.
  file="$1"
  package="$2"

  if [ -e "$file" ]; then
    printf "✓ %-32s vorhanden\n" "$package"
    return
  fi

  printf "→ Installiere %s\n" "$package"

  case "$OS" in
  Darwin)
    brew install "$package"
    ;;
  FreeBSD)
    doas pkg install -y "$package"
    ;;
  esac
}

install_plugins() {
  case "$OS" in
  Darwin)
    install_plugin "/opt/homebrew/share/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh" zsh-syntax-highlighting
    install_plugin "/opt/homebrew/share/zsh-autosuggestions/zsh-autosuggestions.zsh" zsh-autosuggestions
    ;;
  FreeBSD)
    install_plugin "/usr/local/share/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh" zsh-syntax-highlighting
    install_plugin "/usr/local/share/zsh-autosuggestions/zsh-autosuggestions.zsh" zsh-autosuggestions
    ;;
  esac
}

install_tools() {
  install_pkg pwgen pwgen
  install_pkg mc mc
}

set_default_shell() {
  zsh_path="$(command -v zsh)" || die "zsh wurde nicht gefunden."

  if [ "${SHELL:-}" = "$zsh_path" ]; then
    printf "✓ %-32s bereits Login-Shell\n" "zsh"
    return
  fi

  printf "→ Setze zsh als Login-Shell (chsh)\n"
  chsh -s "$zsh_path"
}

main() {
  check_prerequisites
  setup_homebrew_env

  install_prerequisites
  install_plugins
  install_tools
  set_default_shell

  printf "\nzsh-Bootstrap abgeschlossen.\n"
}

main "$@"