#!/bin/bash

# Simple DNS fix that you can run with sudo
# Usage: sudo ./fix-dns-now.sh

set -e

if [ "$EUID" -ne 0 ]; then 
    echo "This script must be run as root (use sudo)"
    exit 1
fi

echo "Fixing DNS configuration..."

# Backup existing resolv.conf
if [ -f /etc/resolv.conf ]; then
    cp /etc/resolv.conf /etc/resolv.conf.backup.$(date +%Y%m%d_%H%M%S)
    echo "✓ Backed up existing resolv.conf"
fi

# Create new resolv.conf with reliable DNS servers
cat > /etc/resolv.conf <<EOF
# DNS configuration - fixed for Docker connectivity
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 1.1.1.1
nameserver 10.255.255.254
EOF

echo "✓ Updated /etc/resolv.conf"

# Prevent WSL from overwriting it (optional)
if [ ! -f /etc/wsl.conf ]; then
    cat > /etc/wsl.conf <<EOF
[network]
generateResolvConf = false
EOF
    echo "✓ Created /etc/wsl.conf to prevent auto-generation"
fi

echo ""
echo "Testing DNS resolution..."
if nslookup registry-1.docker.io > /dev/null 2>&1; then
    echo "✓ DNS resolution working!"
else
    echo "⚠ DNS test failed, but configuration is updated"
    echo "You may need to restart WSL or Docker Desktop"
fi

echo ""
echo "Done! Try running your Docker commands again."
echo "If issues persist, restart Docker Desktop or run: wsl --shutdown (from Windows)"