#!/bin/bash

# Quick DNS fix for WSL2 Docker connectivity issues
# This is a simpler alternative that doesn't require root

set -e

echo "=========================================="
echo "Quick Docker DNS Fix for WSL2"
echo "=========================================="

# Method 1: Fix WSL2 resolv.conf (requires sudo but is quick)
echo ""
echo "Method 1: Fixing WSL2 DNS configuration..."
if [ "$EUID" -eq 0 ]; then
    # Running as root
    if [ -f /etc/resolv.conf ]; then
        cp /etc/resolv.conf /etc/resolv.conf.backup.$(date +%Y%m%d_%H%M%S)
    fi
    
    cat > /etc/resolv.conf <<EOF
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 1.1.1.1
EOF
    
    echo "✓ Updated /etc/resolv.conf"
else
    echo "⚠ Need sudo to update /etc/resolv.conf"
    echo "Run: sudo bash -c 'echo \"nameserver 8.8.8.8\" > /etc/resolv.conf'"
fi

# Method 2: Test DNS resolution
echo ""
echo "Method 2: Testing DNS resolution..."
if nslookup registry-1.docker.io > /dev/null 2>&1 || host registry-1.docker.io > /dev/null 2>&1; then
    echo "✓ DNS resolution working!"
else
    echo "⚠ DNS resolution still failing"
    echo "Try: ping 8.8.8.8 to test basic connectivity"
fi

# Method 3: Docker Desktop specific fix
echo ""
echo "Method 3: Docker Desktop Configuration"
echo "If using Docker Desktop, configure DNS in Docker Desktop settings:"
echo "  1. Open Docker Desktop"
echo "  2. Go to Settings > Resources > Network"
echo "  3. Or Settings > Docker Engine"
echo "  4. Add DNS configuration:"
echo '     {'
echo '       "dns": ["8.8.8.8", "8.8.4.4", "1.1.1.1"]'
echo '     }'
echo "  5. Click 'Apply & Restart'"

# Method 4: Alternative - use Docker's built-in DNS
echo ""
echo "Method 4: Testing Docker with explicit DNS..."
if command -v docker &> /dev/null; then
    echo "Testing Docker connectivity..."
    # Try to pull a small image to test
    if docker pull alpine:latest > /dev/null 2>&1; then
        echo "✓ Docker connectivity working!"
    else
        echo "⚠ Docker pull failed. This might indicate network issues."
        echo ""
        echo "Alternative solutions:"
        echo "1. Restart Docker Desktop"
        echo "2. Restart WSL: wsl --shutdown (from Windows PowerShell)"
        echo "3. Check Windows firewall/antivirus"
        echo "4. Try using a VPN or different network"
    fi
fi

echo ""
echo "=========================================="
echo "Quick fix completed!"
echo "=========================================="
echo ""
echo "If issues persist, try the full fix: sudo ./fix-docker-dns.sh"
echo ""