#!/bin/bash

# MPVJ Headless Setup Script
# Usage: curl -sSL <URL>/setup.sh | sudo bash -s -- <REPO_URL>

set -e

REPO_URL=$1

if [ -z "$REPO_URL" ]; then
    echo "Usage: $0 <REPO_URL>"
    exit 1
fi

# Check for root
if [ "$EUID" -ne 0 ]; then
  echo "Please run as root (use sudo)"
  exit 1
fi

# 1. INTERROGATION PHASE
echo "Interrogating user for configuration..."

# 1.1 Hostname
HOSTNAME=$(whiptail --inputbox "Enter Hostname (e.g. mpvj)" 8 45 "mpvj" --title "Hostname Configuration" 3>&1 1>&2 2>&3) || exit 1
HOSTNAME=${HOSTNAME:-mpvj}

# 1.2 SSID
WIFI_SSID=$(whiptail --inputbox "Enter WiFi SSID (e.g. MPVJ-AP)" 8 45 "MPVJ-AP" --title "WiFi SSID Configuration" 3>&1 1>&2 2>&3) || exit 1
WIFI_SSID=${WIFI_SSID:-MPVJ-AP}

# 1.3 Country Code & Password Validation
while true; do
  WIFI_COUNTRY=$(whiptail --inputbox "Enter 2-letter Country Code (e.g. US, GB, DE)" 8 45 "US" --title "WiFi Country Configuration" 3>&1 1>&2 2>&3) || exit 1
  WIFI_COUNTRY=$(echo "$WIFI_COUNTRY" | tr '[:lower:]' '[:upper:]')
  if [[ ! "$WIFI_COUNTRY" =~ ^[A-Z]{2}$ ]]; then
    whiptail --msgbox "Error: Country Code must be exactly 2 letters (e.g., US)." 8 45
  else
    break
  fi
done

while true; do
  WIFI_PASS=$(whiptail --passwordbox "Enter WiFi Password (minimum 8 characters)" 8 45 --title "WiFi Password Configuration" 3>&1 1>&2 2>&3) || exit 1
  if [ ${#WIFI_PASS} -lt 8 ]; then
    whiptail --msgbox "Error: WiFi Password must be at least 8 characters long (WPA2 requirement)." 8 45
  else
    break
  fi
done

# 2. SYSTEM STAGING PHASE
echo "System Staging Phase..."

# 2.1 Pre-Flight Disk Space Check (2GB Required)
FREE_SPACE_KB=$(df / --output=avail | tail -n1)
MIN_SPACE_KB=2097152 # 2GB
if [ "$FREE_SPACE_KB" -lt "$MIN_SPACE_KB" ]; then
  whiptail --msgbox "Error: Not enough disk space. At least 2GB of free space is required." 8 45
  exit 1
fi

# 2.2 System Updates
(
  echo 25
  apt-get update -y > /dev/null 2>&1
  echo 75
  DEBIAN_FRONTEND=noninteractive apt-get upgrade -y > /dev/null 2>&1
  echo 100
) | whiptail --gauge "Updating System Packages..." 6 60 0

# 2.3 Install Dependencies
(
  echo 20
  DEBIAN_FRONTEND=noninteractive apt-get install -y git hostapd dnsmasq avahi-daemon curl > /dev/null 2>&1
  echo 60
  curl -fsSL https://deb.nodesource.com/setup_20.x | bash - > /dev/null 2>&1
  DEBIAN_FRONTEND=noninteractive apt-get install -y nodejs > /dev/null 2>&1
  echo 100
) | whiptail --gauge "Installing Core Dependencies..." 6 60 0

# 2.4 Hostname & Country Code
hostnamectl set-hostname "$HOSTNAME"
sed -i "s/127.0.1.1.*/127.0.1.1\t$HOSTNAME/g" /etc/hosts
if command -v raspi-config > /dev/null; then
  raspi-config nonint do_wifi_country "$WIFI_COUNTRY" > /dev/null 2>&1
fi

# 2.5 Swap Increase
if [ -f /etc/dphys-swapfile ]; then
  sed -i "s/CONF_SWAPSIZE=.*/CONF_SWAPSIZE=1024/g" /etc/dphys-swapfile
  dphys-swapfile setup
  dphys-swapfile swapon
fi

# 3. NETWORKING CONFIGURATION
echo "Configuring Networking..."

# 3.1 hostapd
cat <<EOF > /etc/hostapd/hostapd.conf
interface=wlan0
driver=nl80211
ssid=$WIFI_SSID
hw_mode=g
channel=7
wpa=2
wpa_passphrase=$WIFI_PASS
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
auth_algs=1
macaddr_acl=0
EOF
sed -i 's/#DAEMON_CONF=""/DAEMON_CONF="\/etc\/hostapd\/hostapd.conf"/g' /etc/default/hostapd

# 3.2 dnsmasq
mv /etc/dnsmasq.conf /etc/dnsmasq.conf.bak 2>/dev/null || true
cat <<EOF > /etc/dnsmasq.conf
interface=wlan0
dhcp-range=192.168.4.2,192.168.4.20,255.255.255.0,24h
domain=local
address=/$HOSTNAME.local/192.168.4.1
EOF

# 3.3 dhcpcd
if ! grep -q "interface wlan0" /etc/dhcpcd.conf; then
cat <<EOF >> /etc/dhcpcd.conf
interface wlan0
    static ip_address=192.168.4.1/24
    nohook wpa_supplicant
EOF
fi

# 3.4 Avahi
cat <<EOF > /etc/avahi/services/mpvj.service
<?xml version="1.0" standalone='no'?>
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
  <name replace-wildcards="yes">MPVJ Control Center</name>
  <service>
    <type>_http._tcp</type>
    <port>80</port>
  </service>
</service-group>
EOF
sed -i 's/#use-ipv4-ll=yes/use-ipv4-ll=yes/g' /etc/avahi/avahi-daemon.conf

# 4. APPLICATION DEPLOYMENT
echo "Deploying Application..."

# 4.1 Clone
[ -d /home/pi/mpvj ] && mv /home/pi/mpvj /home/pi/mpvj.old.$(date +%s)
git clone "$REPO_URL" /home/pi/mpvj
mkdir -p /home/pi/media
chown -R pi:pi /home/pi/mpvj /home/pi/media

# 4.2 Build
export NODE_OPTIONS="--max-old-space-size=512"
cd /home/pi/mpvj/backend
sudo -u pi npm install --jobs 1
cd /home/pi/mpvj/frontend
if [ ! -d "dist" ]; then
  sudo -u pi npm install --jobs 1
  sudo -u pi npm run build
fi

# 4.3 Systemd
cat <<EOF > /etc/systemd/system/mpvj-backend.service
[Unit]
Description=MPVJ Headless Control Center Backend
After=network.target

[Service]
Type=simple
User=pi
WorkingDirectory=/home/pi/mpvj/backend
ExecStart=/usr/bin/node index.js
Restart=on-failure
Environment=NODE_OPTIONS=--max-old-space-size=512

[Install]
WantedBy=multi-user.target
EOF
systemctl daemon-reload
systemctl enable mpvj-backend.service

# 4.4 .env
cat <<EOF > /home/pi/mpvj/backend/.env
PORT=80
MPVJ_HOSTNAME=$HOSTNAME
MPVJ_SSID=$WIFI_SSID
MPVJ_WIFI_PASS=$WIFI_PASS
MPVJ_REPO_URL=$REPO_URL
MPVJ_MEDIA_DIR=/home/pi/media
EOF
chown pi:pi /home/pi/mpvj/backend/.env
chmod 600 /home/pi/mpvj/backend/.env

# 5. FINALIZATION
echo "Finalizing..."

# 5.1 Revert Swap
if [ -f /etc/dphys-swapfile ]; then
  sed -i "s/CONF_SWAPSIZE=.*/CONF_SWAPSIZE=100/g" /etc/dphys-swapfile
  dphys-swapfile setup
  dphys-swapfile swapon
fi

# 5.2 Summary
SUMMARY="MPVJ INSTALLATION COMPLETE\n\n"
SUMMARY+="Please NOTE DOWN these details before rebooting:\n\n"
SUMMARY+="HOSTNAME:   $HOSTNAME.local\n"
SUMMARY+="STATIC IP:  192.168.4.1\n"
SUMMARY+="WIFI SSID:  $WIFI_SSID\n"
SUMMARY+="WIFI PASS:  $WIFI_PASS\n\n"
SUMMARY+="Your SSH password remains unchanged.\n"
SUMMARY+="Connect to '$WIFI_SSID' after reboot.\n\n"
SUMMARY+="Reboot now?"

if whiptail --title "Success" --yesno "$SUMMARY" 20 60; then
  reboot
fi