#!/bin/sh

echo "Creating WAN Watchdog script at /usr/bin/wan-watchdog.sh..."

cat << 'EOF' > /usr/bin/wan-watchdog.sh
#!/bin/sh

LED_BLUE="/sys/class/leds/blue:status/brightness"
LED_GREEN="/sys/class/leds/green:status/brightness"
LED_RED="/sys/class/leds/red:status/brightness"
STATE_FILE="/tmp/wan_led_state"

set_rgb() {
    local r=$1 g=$2 b=$3
    local new_state="$r$g$b"
    
    # Only update if the state changed
    if [ "$(cat $STATE_FILE 2>/dev/null)" != "$new_state" ]; then
        echo "$r" > "$LED_RED"
        echo "$g" > "$LED_GREEN"
        echo "$b" > "$LED_BLUE"
        echo "$new_state" > "$STATE_FILE"
    fi
}

while true; do
    # Get the interface currently handling the default route
    ACTIVE_IF=$(ip route get 1.1.1.1 2>/dev/null | awk '/dev/ {print $5; exit}')

    if [ -z "$ACTIVE_IF" ]; then
        # No gateway found
        set_rgb 0 0 1 # Blue
    else
        # Try a quick ping through that specific interface
        if ping -I "$ACTIVE_IF" -c 1 -W 2 1.1.1.1 >/dev/null 2>&1; then
            set_rgb 1 1 1 # White
        else
            set_rgb 1 0 0 # Red
        fi
    fi
    sleep 10
done
EOF

echo "Creating Init Service at /etc/init.d/wan-led..."

cat << 'EOF' > /etc/init.d/wan-led
#!/bin/sh /etc/rc.common

USE_PROCD=1
START=99

start_service() {
    procd_open_instance
    procd_set_param command /usr/bin/wan-watchdog.sh
    procd_set_param respawn
    procd_set_param stdout 1
    procd_set_param stderr 1
    procd_close_instance
}

stop_service() {
    # Reset LEDs when service stops
    echo 0 > /sys/class/leds/blue:status/brightness
    echo 0 > /sys/class/leds/green:status/brightness
    echo 1 > /sys/class/leds/red:status/brightness
    rm -f /tmp/wan_led_state
}
EOF

echo "Setting executable permissions..."
chmod +x /usr/bin/wan-watchdog.sh
chmod +x /etc/init.d/wan-led

echo "Adding files to /etc/sysupgrade.conf to survive backups..."
grep -qxF '/usr/bin/wan-watchdog.sh' /etc/sysupgrade.conf || echo '/usr/bin/wan-watchdog.sh' >> /etc/sysupgrade.conf
grep -qxF '/etc/init.d/wan-led' /etc/sysupgrade.conf || echo '/etc/init.d/wan-led' >> /etc/sysupgrade.conf

echo "Securing startup sequence in /etc/rc.local..."
if ! grep -q "/etc/init.d/wan-led" /etc/rc.local; then
    sed -i '/^exit 0/d' /etc/rc.local
    cat << 'EOF' >> /etc/rc.local

# Ensure WAN LED watchdog is enabled and running after sysupgrade
if [ -x /etc/init.d/wan-led ]; then
    /etc/init.d/wan-led enabled || /etc/init.d/wan-led enable
    /etc/init.d/wan-led start
fi

exit 0
EOF
fi

echo "Enabling and starting wan-led service..."
/etc/init.d/wan-led enable
/etc/init.d/wan-led start

echo "Installation complete! Service is running and upgrade-proof."