send email if External IP Has Changed

#!/bin/bash

# === Config ===
EMAIL="youremail"
IP_FILE="$HOME/.last_public_ip"
IP_CHECK_URL="https://api.ipify.org"
LOGFILE="$HOME/ip_check.log"

# === Ensure msmtp and expressvpn are installed ===
command -v msmtp >/dev/null 2>&1 || { echo "❌ msmtp not found. Exiting."; exit 1; }
command -v expressvpn >/dev/null 2>&1 || { echo "❌ expressvpn not found. Exiting."; exit 1; }

# === Optional: Check if VPN is active ===
VPN_STATUS=$(expressvpn status)
echo "🔒 VPN status: $VPN_STATUS" >> "$LOGFILE"

if echo "$VPN_STATUS" | grep -q "Connected"; then
    echo "📴 Disconnecting ExpressVPN to fetch real IP..." >> "$LOGFILE"
    expressvpn disconnect
    sleep 5
fi

# === Get current real public IP ===
CURRENT_IP=$(curl -s "$IP_CHECK_URL" | tr -d '[:space:]')
[ -z "$CURRENT_IP" ] && echo "❌ Error: Could not retrieve IP." >> "$LOGFILE" && exit 1

# === Reconnect VPN ===
echo "🔄 Reconnecting ExpressVPN..." >> "$LOGFILE"
expressvpn connect
sleep 5

# === Load last known IP ===
[ -f "$IP_FILE" ] && LAST_IP=$(tr -d '[:space:]' < "$IP_FILE") || LAST_IP=""

# === Debug Output ===
echo "📡 Current IP: [$CURRENT_IP] | Last IP: [$LAST_IP]" >> "$LOGFILE"

# === Compare and act ===
if [ "$CURRENT_IP" != "$LAST_IP" ]; then
    printf "%s\n" "$CURRENT_IP" > "$IP_FILE"
    HOSTNAME=$(hostname)
    TIMESTAMP=$(date)

    echo -e "From: $EMAIL\nTo: $EMAIL\nSubject: [${HOSTNAME}] Public IP Changed to $CURRENT_IP\n\nDate: $TIMESTAMP\nHostname: $HOSTNAME\nNew Public IP: $CURRENT_IP" | msmtp "$EMAIL"

    echo "✅ IP changed to $CURRENT_IP. Email sent. [$TIMESTAMP]" >> "$LOGFILE"
else
    echo "ℹ️ IP unchanged. No email sent. [$TIMESTAMP]" >> "$LOGFILE"
fi