#!/bin/sh

set -e

ROUTER_TYPE="$1"

echo "Setting up $ROUTER_TYPE router..."

# fix dns 
echo "nameserver 192.168.10.1" > /etc/resolv.conf

apk add --no-cache iputils iptables

# Enable IP forwarding
echo 1 > /proc/sys/net/ipv4/ip_forward
sysctl -w net.ipv4.ip_forward=1

if [ "$ROUTER_TYPE" = "primary" ]; then
    echo "Configuring PRIMARY router (192.168.200.11 192.168.202.11 172.17.0.2)"
    
    ip addr show
    echo "Routes:"
    ip route show
    
    # NAT for traffic from primary network to target network
    iptables -t nat -A POSTROUTING -s 192.168.200.0/24 -d 192.168.202.0/24 -j MASQUERADE
    iptables -P FORWARD ACCEPT

elif [ "$ROUTER_TYPE" = "secondary" ]; then
    echo "Configuring SECONDARY router (192.168.201.11 ↔ 192.168.202.12 ↔ 172.17.0.3)"
    
    ip addr show
    echo "Routes:"
    ip route show
    
    # NAT for traffic from secondary network to target network
    iptables -t nat -A POSTROUTING -s 192.168.201.0/24 -d 192.168.202.0/24 -j MASQUERADE
    iptables -P FORWARD ACCEPT
else
    echo "Error: Invalid router type. Use 'primary' or 'secondary'"
    exit 1
fi

echo "Secondary router setup complete"
echo "NAT rules:"
iptables -t nat -L POSTROUTING -n -v

# Keep container running
echo "Router is running. Monitoring interfaces..."
while true; do
    echo "$(date): Router $ROUTER_TYPE status - interfaces up"
    sleep 60
done