#!/bin/bash

# WebDAV External Access Diagnostic Script
# This script helps diagnose why WebDAV is not accessible from external networks

echo "=========================================="
echo "WebDAV External Access Diagnostic Tool"
echo "=========================================="
echo ""

# Check if running as root (needed for some checks)
if [ "$EUID" -ne 0 ]; then 
    echo "⚠️  Some checks may require root privileges"
    echo ""
fi

# 1. Check what's listening on port 5006
echo "1. Checking what's listening on port 5006..."
echo "-------------------------------------------"
if command -v netstat &> /dev/null; then
    echo "Using netstat:"
    netstat -tuln | grep 5006 || echo "❌ Nothing found listening on port 5006"
elif command -v ss &> /dev/null; then
    echo "Using ss:"
    ss -tuln | grep 5006 || echo "❌ Nothing found listening on port 5006"
else
    echo "⚠️  netstat or ss not available"
fi
echo ""

# 2. Check if service is bound to localhost only
echo "2. Checking if service is bound to localhost only..."
echo "-------------------------------------------"
if command -v netstat &> /dev/null; then
    netstat -tuln | grep 5006 | grep "127.0.0.1\|::1" && echo "❌ Service is bound to localhost only!" || echo "✅ Service is not bound to localhost only"
elif command -v ss &> /dev/null; then
    ss -tuln | grep 5006 | grep "127.0.0.1\|::1" && echo "❌ Service is bound to localhost only!" || echo "✅ Service is not bound to localhost only"
fi
echo ""

# 3. Check if port 5006 is open in firewall
echo "3. Checking firewall status..."
echo "-------------------------------------------"
if command -v ufw &> /dev/null; then
    echo "UFW Status:"
    ufw status | grep 5006 || echo "⚠️  Port 5006 not found in UFW rules"
elif command -v firewall-cmd &> /dev/null; then
    echo "firewalld Status:"
    firewall-cmd --list-ports | grep 5006 || echo "⚠️  Port 5006 not found in firewalld rules"
elif command -v iptables &> /dev/null; then
    echo "iptables rules for port 5006:"
    iptables -L -n | grep 5006 || echo "⚠️  No iptables rules found for port 5006"
else
    echo "⚠️  No common firewall tool detected"
fi
echo ""

# 4. Check WebDAV service status (common services)
echo "4. Checking WebDAV service status..."
echo "-------------------------------------------"
if systemctl list-units --type=service | grep -i webdav &> /dev/null; then
    systemctl list-units --type=service | grep -i webdav | while read service; do
        servicename=$(echo $service | awk '{print $1}')
        echo "Service: $servicename"
        systemctl status $servicename --no-pager | head -5
    done
else
    echo "⚠️  No WebDAV systemd service found"
    echo "Checking common WebDAV processes:"
    ps aux | grep -i webdav | grep -v grep || echo "No WebDAV processes found"
fi
echo ""

# 5. Test local connection
echo "5. Testing local connection to port 5006..."
echo "-------------------------------------------"
if command -v nc &> /dev/null; then
    if nc -zv localhost 5006 2>&1; then
        echo "✅ Local connection successful"
    else
        echo "❌ Local connection failed"
    fi
else
    echo "⚠️  netcat (nc) not available for connection test"
fi
echo ""

# 6. Check network interfaces
echo "6. Network interface information..."
echo "-------------------------------------------"
if command -v ip &> /dev/null; then
    ip addr show | grep -E "^[0-9]+:|inet " | head -10
elif command -v ifconfig &> /dev/null; then
    ifconfig | grep -E "^[a-z]|inet " | head -10
fi
echo ""

# 7. Check router/NAT configuration hints
echo "7. Router/NAT Configuration Checklist..."
echo "-------------------------------------------"
echo "Please verify on your router/NAS:"
echo "  □ Port forwarding: External port 5006 → Internal NAS IP:5006"
echo "  □ Firewall rules allow incoming connections on port 5006"
echo "  □ NAT/UPnP is configured correctly"
echo "  □ External IP matches: $(curl -s ifconfig.me 2>/dev/null || echo 'Unable to determine')"
echo ""

# 8. Common WebDAV configuration files to check
echo "8. Common WebDAV configuration locations..."
echo "-------------------------------------------"
config_locations=(
    "/etc/apache2/sites-available/*webdav*"
    "/etc/apache2/conf.d/*webdav*"
    "/etc/nginx/sites-available/*webdav*"
    "/etc/nginx/conf.d/*webdav*"
    "/etc/lighttpd/lighttpd.conf"
    "/etc/httpd/conf.d/*webdav*"
    "/usr/local/etc/apache2/*webdav*"
)

for pattern in "${config_locations[@]}"; do
    for file in $pattern; do
        if [ -f "$file" ]; then
            echo "Found: $file"
            echo "  Checking for Listen/ServerName directives..."
            grep -E "Listen|ServerName|<VirtualHost|listen" "$file" | head -3 || true
        fi
    done
done
echo ""

echo "=========================================="
echo "Diagnostic Complete"
echo "=========================================="
echo ""
echo "Common Issues and Solutions:"
echo "1. If service is bound to 127.0.0.1: Change Listen directive to 0.0.0.0:5006"
echo "2. If firewall blocks port: Open port 5006 in firewall"
echo "3. If router blocks: Configure port forwarding for port 5006"
echo "4. If service not running: Start the WebDAV service"
echo ""