#!/usr/bin/env bash
set -euo pipefail

SCRIPT_PATH="${BASH_SOURCE[0]:-}"
if [ -n "${SCRIPT_PATH}" ] && [ "${SCRIPT_PATH}" != "bash" ] && [ "${SCRIPT_PATH}" != "-" ] && [ -f "${SCRIPT_PATH}" ]; then
  SCRIPT_DIR="$(cd "$(dirname "${SCRIPT_PATH}")" && pwd)"
else
  SCRIPT_DIR="$(pwd)"
fi
REPO_URL="https://github.com/zakstam/zenbook-duo-linux.git"
ARCHIVE_URL="https://github.com/zakstam/zenbook-duo-linux/archive/refs/heads/main.tar.gz"

usage() {
  cat <<'EOF'
install.sh - unified installer for Zenbook Duo Linux

Usage:
  ./install.sh [install-options...] [-- setup-script-args...]

Examples:
  ./install.sh
  ./install.sh --build-only
  ./install.sh --install-only
  ./install.sh --skip-ui
  ./install.sh --no-usb-media-remap
  ./install.sh -- --no-usb-media-remap
  sudo -E ./install.sh

This script auto-detects GNOME, KDE Plasma, or Niri, runs the matching setup
script, then installs the Zenbook Duo Control UI unless --skip-ui is passed.

Use ./build.sh to compile runtime + UI without installing system services.
EOF
}

ensure_repo_checkout() {
  if [ -f "${SCRIPT_DIR}/setup-gnome.sh" ] && [ -f "${SCRIPT_DIR}/setup-common.sh" ] && [ -f "${SCRIPT_DIR}/install-ui.sh" ]; then
    printf '%s\n' "${SCRIPT_DIR}"
    return 0
  fi

  local temp_dir
  temp_dir="$(mktemp -d -t zenbook-duo-linux.XXXXXX)"

  if command -v git >/dev/null 2>&1; then
    echo "Downloading zenbook-duo-linux..." >&2
    git clone --depth 1 "${REPO_URL}" "${temp_dir}" >/dev/null 2>&1
    printf '%s\n' "${temp_dir}"
    return 0
  fi

  if command -v curl >/dev/null 2>&1 && command -v tar >/dev/null 2>&1; then
    echo "Downloading zenbook-duo-linux..." >&2
    curl -fsSL "${ARCHIVE_URL}" | tar -xz -C "${temp_dir}" --strip-components=1
    printf '%s\n' "${temp_dir}"
    return 0
  fi

  echo "ERROR: Could not download the repository automatically." >&2
  echo "Install one of these first, then try again: git or (curl and tar)." >&2
  exit 1
}

lower() {
  printf '%s' "${1:-}" | tr '[:upper:]' '[:lower:]'
}

contains_token() {
  local haystack=" ${1:-} "
  local needle="${2:-}"
  [[ "${haystack}" == *" ${needle} "* ]]
}

pick_desktop() {
  local current_desktop_raw="${XDG_CURRENT_DESKTOP:-}"
  local desktop_session_raw="${DESKTOP_SESSION:-}"
  local session_desktop_raw="${XDG_SESSION_DESKTOP:-}"

  local current_desktop
  local desktop_session
  local session_desktop
  current_desktop="$(lower "${current_desktop_raw}")"
  desktop_session="$(lower "${desktop_session_raw}")"
  session_desktop="$(lower "${session_desktop_raw}")"

  local detected=()
  for value in "${current_desktop//:/ }" "${desktop_session}" "${session_desktop}"; do
    [ -n "${value}" ] || continue
    if contains_token "${value}" "gnome"; then
      detected+=("gnome")
    fi
    if contains_token "${value}" "kde" || contains_token "${value}" "plasma"; then
      detected+=("kde")
    fi
    if contains_token "${value}" "niri"; then
      detected+=("niri")
    fi
  done

  local unique=()
  local item
  for item in "${detected[@]:-}"; do
    local seen=false
    local existing
    for existing in "${unique[@]:-}"; do
      if [ "${existing}" = "${item}" ]; then
        seen=true
        break
      fi
    done
    if [ "${seen}" = false ]; then
      unique+=("${item}")
    fi
  done

  if [ "${#unique[@]}" -eq 1 ]; then
    printf '%s\n' "${unique[0]}"
    return 0
  fi

  echo "ERROR: Could not confidently detect a supported desktop session." >&2
  echo "Detected environment values:" >&2
  echo "  XDG_CURRENT_DESKTOP=${current_desktop_raw:-<empty>}" >&2
  echo "  DESKTOP_SESSION=${desktop_session_raw:-<empty>}" >&2
  echo "  XDG_SESSION_DESKTOP=${session_desktop_raw:-<empty>}" >&2
  echo >&2
  echo "Run one of these manually instead:" >&2
  echo "  ./setup-gnome.sh" >&2
  echo "  ./setup-kde.sh" >&2
  echo "  ./setup-niri.sh" >&2
  return 1
}

if [ "${1:-}" = "-h" ] || [ "${1:-}" = "--help" ]; then
  usage
  exit 0
fi

INSTALL_UI=true
BUILD_ONLY=false
INSTALL_ONLY=false
SETUP_ARGS=()
while [ "$#" -gt 0 ]; do
  case "$1" in
    --skip-ui)
      INSTALL_UI=false
      shift
      ;;
    --build-only)
      BUILD_ONLY=true
      shift
      ;;
    --install-only)
      INSTALL_ONLY=true
      shift
      ;;
    --)
      shift
      SETUP_ARGS+=("$@")
      break
      ;;
    *)
      SETUP_ARGS+=("$1")
      shift
      ;;
  esac
done

if [ "${BUILD_ONLY}" = true ] && [ "${INSTALL_ONLY}" = true ]; then
  echo "ERROR: Choose only one of --build-only or --install-only" >&2
  exit 1
fi

if [ "${BUILD_ONLY}" = true ]; then
  export DUO_RUNTIME_MODE="build-only"
elif [ "${INSTALL_ONLY}" = true ]; then
  export DUO_RUNTIME_MODE="install-only"
fi

desktop="$(pick_desktop)"
repo_dir="$(ensure_repo_checkout)"
repo_dir_is_temp=false
if [ "${repo_dir}" != "${SCRIPT_DIR}" ] && [[ "${repo_dir}" == /tmp/* || "${repo_dir}" == /var/tmp/* || "${repo_dir}" == /private/tmp/* ]]; then
  repo_dir_is_temp=true
fi
cleanup() {
  if [ "${repo_dir_is_temp}" = true ]; then
    rm -rf "${repo_dir}"
  fi
}
trap cleanup EXIT

case "${desktop}" in
  gnome)
    setup_script="${repo_dir}/setup-gnome.sh"
    ;;
  kde)
    setup_script="${repo_dir}/setup-kde.sh"
    ;;
  niri)
    setup_script="${repo_dir}/setup-niri.sh"
    ;;
  *)
    echo "ERROR: Unsupported desktop target: ${desktop}" >&2
    exit 1
    ;;
esac

echo "Detected desktop: ${desktop}"
echo "Running $(basename "${setup_script}")..."
if [ -r /dev/tty ]; then
  "${setup_script}" "${SETUP_ARGS[@]}" </dev/tty
else
  "${setup_script}" "${SETUP_ARGS[@]}"
fi

if [ "${INSTALL_UI}" = true ]; then
  UI_ARGS=()
  if [ "${repo_dir}" = "${SCRIPT_DIR}" ] && [ -e "${repo_dir}/.git" ]; then
    UI_ARGS=(--dir "${repo_dir}")
  elif [ "${repo_dir}" != "${SCRIPT_DIR}" ]; then
    UI_ARGS=(--dir "${repo_dir}")
  fi
  if [ "${BUILD_ONLY}" = true ]; then
    UI_ARGS+=(--build-only --skip-prereqs)
  elif [ "${INSTALL_ONLY}" = true ]; then
    UI_ARGS+=(--install-only --skip-prereqs)
  fi

  echo "Running install-ui.sh ${UI_ARGS[*]}..."
  if [ -r /dev/tty ]; then
    "${repo_dir}/install-ui.sh" "${UI_ARGS[@]}" </dev/tty
  else
    "${repo_dir}/install-ui.sh" "${UI_ARGS[@]}"
  fi
else
  echo "Skipping UI install (--skip-ui)."
fi

echo
echo "If this is a fresh install, you may need to log out and back in."
echo "If anything looks stale after updating, run: systemctl --user restart zenbook-duo-session-agent.service"