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

if [[ "${EUID}" -ne 0 ]]; then
  echo "Bitte als root ausfuehren: sudo ./install.sh"
  exit 1
fi

PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
APP_ROOT="/opt/serial-bridge"
CONFIG_ROOT="/etc/serial-bridge"
VENV_PY="${APP_ROOT}/.venv/bin/python"
REQ_HASH_FILE="${APP_ROOT}/.requirements.sha256"
NEEDS_APT=0
NEEDS_VENV=0
NEEDS_PIP=0

REQUIRED_PACKAGES=(
  python3
  python3-venv
  python3-pip
  hostapd
  dnsmasq
  iw
  wpasupplicant
  iproute2
  rfkill
  i2c-tools
)

is_installed() {
  [[ -d "${APP_ROOT}/src" ]] && [[ -f "/etc/systemd/system/serial-bridge.service" ]]
}

all_packages_installed() {
  local pkg
  for pkg in "${REQUIRED_PACKAGES[@]}"; do
    if ! dpkg -s "${pkg}" >/dev/null 2>&1; then
      return 1
    fi
  done
  return 0
}

compute_req_hash() {
  sha256sum "${PROJECT_ROOT}/requirements.txt" | awk '{print $1}'
}

mode="install"
if is_installed; then
  mode="update"
fi

echo "Modus: ${mode}"

if ! all_packages_installed; then
  NEEDS_APT=1
fi

if [[ ! -x "${VENV_PY}" ]]; then
  NEEDS_VENV=1
fi

current_req_hash="$(compute_req_hash)"
stored_req_hash=""
if [[ -f "${REQ_HASH_FILE}" ]]; then
  stored_req_hash="$(cat "${REQ_HASH_FILE}" 2>/dev/null || true)"
fi
if [[ "${NEEDS_VENV}" -eq 1 ]] || [[ "${current_req_hash}" != "${stored_req_hash}" ]]; then
  NEEDS_PIP=1
fi

if [[ "${NEEDS_APT}" -eq 1 ]]; then
  echo "Installiere fehlende Systempakete..."
  apt-get update
  apt-get install -y "${REQUIRED_PACKAGES[@]}"
else
  echo "Systempakete bereits vorhanden, ueberspringe apt."
fi

install -d -m 755 "${APP_ROOT}" "${APP_ROOT}/src" "${APP_ROOT}/templates" "${APP_ROOT}/static" "${CONFIG_ROOT}"

cp -a "${PROJECT_ROOT}/src/." "${APP_ROOT}/src/"
cp -a "${PROJECT_ROOT}/templates/." "${APP_ROOT}/templates/"
cp -a "${PROJECT_ROOT}/static/." "${APP_ROOT}/static/"
cp "${PROJECT_ROOT}/requirements.txt" "${APP_ROOT}/requirements.txt"

if [[ "${NEEDS_VENV}" -eq 1 ]]; then
  echo "Erstelle Python venv..."
  python3 -m venv "${APP_ROOT}/.venv"
fi

if [[ "${NEEDS_PIP}" -eq 1 ]]; then
  echo "Aktualisiere Python-Abhaengigkeiten..."
  "${APP_ROOT}/.venv/bin/pip" install --upgrade pip
  "${APP_ROOT}/.venv/bin/pip" install -r "${APP_ROOT}/requirements.txt"
  echo "${current_req_hash}" > "${REQ_HASH_FILE}"
else
  echo "requirements.txt unveraendert, ueberspringe pip install."
fi

install -m 644 "${PROJECT_ROOT}/config/hostapd.conf" "${CONFIG_ROOT}/hostapd.conf"
install -m 644 "${PROJECT_ROOT}/config/dnsmasq.conf" "${CONFIG_ROOT}/dnsmasq.conf"

install -m 644 "${PROJECT_ROOT}/systemd/serial-hostapd.service" "/etc/systemd/system/serial-hostapd.service"
install -m 644 "${PROJECT_ROOT}/systemd/serial-dnsmasq.service" "/etc/systemd/system/serial-dnsmasq.service"
install -m 644 "${PROJECT_ROOT}/systemd/serial-bridge.service" "/etc/systemd/system/serial-bridge.service"

WPA_CONF="/etc/wpa_supplicant/wpa_supplicant.conf"
touch "${WPA_CONF}"
grep -q '^ctrl_interface=' "${WPA_CONF}" || echo 'ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev' >> "${WPA_CONF}"
grep -q '^update_config=' "${WPA_CONF}" || echo 'update_config=1' >> "${WPA_CONF}"

systemctl disable --now hostapd.service || true
systemctl disable --now dnsmasq.service || true

install -d -m 755 /home/pi
chown pi:pi /home/pi || true

systemctl daemon-reload
systemctl enable serial-bridge.service
systemctl restart serial-bridge.service

echo "Fertig (${mode}). Logs: journalctl -u serial-bridge -f"