#!/bin/bash

# Nginx SSL Configuration Script
# Automatically configures nginx with SSL certificates for dev.uggla.uamils.com

set -e

# Configuration
DOMAIN="${DOMAIN:-dev.uggla.uamils.com}"
CERT_PATH="/etc/letsencrypt/live/$DOMAIN"
SITES_AVAILABLE="/etc/nginx/sites-available"
SITES_ENABLED="/etc/nginx/sites-enabled"
CONFIG_NAME="$DOMAIN"

# Backend and frontend ports (from docker-compose)
BACKEND_PORT="${BACKEND_PORT:-3002}"
FRONTEND_PORT="${FRONTEND_PORT:-3001}"

log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1"
}

check_prerequisites() {
    log "Checking prerequisites..."
    
    # Check if running as root
    if [[ $EUID -ne 0 ]]; then
        log "ERROR: This script must be run as root (use sudo)"
        exit 1
    fi
    
    # Check if nginx is installed
    if ! command -v nginx >/dev/null 2>&1; then
        log "ERROR: Nginx is not installed. Install with: sudo apt install nginx"
        exit 1
    fi
    
    # Check if certificates exist
    if [[ ! -f "$CERT_PATH/fullchain.pem" || ! -f "$CERT_PATH/privkey.pem" ]]; then
        log "ERROR: SSL certificates not found at $CERT_PATH"
        log "Please run SSL certificate generation first:"
        log "  cd ssl && ./certbot-manager.sh renew"
        exit 1
    fi
    
    log "Prerequisites check passed"
}

create_nginx_config() {
    log "Creating nginx configuration for $DOMAIN..."
    
    cat > "$SITES_AVAILABLE/$CONFIG_NAME" << EOF
# Nginx configuration for $DOMAIN
# Multi-tenant drone detection system with SSL

# HTTP to HTTPS redirect
server {
    listen 80;
    server_name $DOMAIN *.$DOMAIN;
    
    # ACME challenge location for Let's Encrypt
    location /.well-known/acme-challenge/ {
        root /var/www/html;
        try_files \$uri =404;
    }
    
    # Redirect all other traffic to HTTPS
    location / {
        return 301 https://\$server_name\$request_uri;
    }
}

# HTTPS server for main domain
server {
    listen 443 ssl http2;
    server_name $DOMAIN;
    
    # SSL Configuration
    ssl_certificate $CERT_PATH/fullchain.pem;
    ssl_certificate_key $CERT_PATH/privkey.pem;
    
    # SSL Security Settings
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-RSA-AES256-GCM-SHA512:DHE-RSA-AES256-GCM-SHA512:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384;
    ssl_prefer_server_ciphers off;
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;
    ssl_stapling on;
    ssl_stapling_verify on;
    
    # Security Headers
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    add_header X-Frame-Options DENY always;
    add_header X-Content-Type-Options nosniff always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    
    # Root location - serve frontend
    location / {
        proxy_pass http://127.0.0.1:$FRONTEND_PORT;
        proxy_http_version 1.1;
        proxy_set_header Upgrade \$http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host \$host;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
        proxy_cache_bypass \$http_upgrade;
        
        # Timeouts
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
    }
    
    # API routes - proxy to backend
    location /api/ {
        proxy_pass http://127.0.0.1:$BACKEND_PORT;
        proxy_http_version 1.1;
        proxy_set_header Upgrade \$http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host \$host;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
        proxy_cache_bypass \$http_upgrade;
        
        # Timeouts
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
    }
    
    # Health check endpoint
    location /health {
        proxy_pass http://127.0.0.1:$BACKEND_PORT;
        proxy_set_header Host \$host;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
    }
    
    # WebSocket support for real-time features
    location /ws {
        proxy_pass http://127.0.0.1:$BACKEND_PORT;
        proxy_http_version 1.1;
        proxy_set_header Upgrade \$http_upgrade;
        proxy_set_header Connection "Upgrade";
        proxy_set_header Host \$host;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
    }
    
    # Static files (if served directly by nginx)
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)\$ {
        proxy_pass http://127.0.0.1:$FRONTEND_PORT;
        expires 1y;
        add_header Cache-Control "public, immutable";
    }
}

# HTTPS server for wildcard subdomains (multi-tenant)
server {
    listen 443 ssl http2;
    server_name *.$DOMAIN;
    
    # SSL Configuration (same certificates work for wildcard)
    ssl_certificate $CERT_PATH/fullchain.pem;
    ssl_certificate_key $CERT_PATH/privkey.pem;
    
    # SSL Security Settings (same as main domain)
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-RSA-AES256-GCM-SHA512:DHE-RSA-AES256-GCM-SHA512:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384;
    ssl_prefer_server_ciphers off;
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;
    ssl_stapling on;
    ssl_stapling_verify on;
    
    # Security Headers
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    add_header X-Frame-Options DENY always;
    add_header X-Content-Type-Options nosniff always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    
    # Multi-tenant routing - pass subdomain to backend
    location / {
        proxy_pass http://127.0.0.1:$FRONTEND_PORT;
        proxy_http_version 1.1;
        proxy_set_header Upgrade \$http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host \$host;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
        proxy_set_header X-Tenant-Domain \$host;
        proxy_cache_bypass \$http_upgrade;
        
        # Timeouts
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
    }
    
    # API routes for multi-tenant
    location /api/ {
        proxy_pass http://127.0.0.1:$BACKEND_PORT;
        proxy_http_version 1.1;
        proxy_set_header Upgrade \$http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host \$host;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
        proxy_set_header X-Tenant-Domain \$host;
        proxy_cache_bypass \$http_upgrade;
        
        # Timeouts
        proxy_connect_timeout 30s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
    }
    
    # Health check for subdomains
    location /health {
        proxy_pass http://127.0.0.1:$BACKEND_PORT;
        proxy_set_header Host \$host;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
        proxy_set_header X-Tenant-Domain \$host;
    }
    
    # WebSocket support for multi-tenant
    location /ws {
        proxy_pass http://127.0.0.1:$BACKEND_PORT;
        proxy_http_version 1.1;
        proxy_set_header Upgrade \$http_upgrade;
        proxy_set_header Connection "Upgrade";
        proxy_set_header Host \$host;
        proxy_set_header X-Real-IP \$remote_addr;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto \$scheme;
        proxy_set_header X-Tenant-Domain \$host;
    }
}
EOF

    log "Nginx configuration created at $SITES_AVAILABLE/$CONFIG_NAME"
}

enable_site() {
    log "Enabling nginx site..."
    
    # Remove default site if it exists
    if [[ -f "$SITES_ENABLED/default" ]]; then
        log "Removing default nginx site"
        rm -f "$SITES_ENABLED/default"
    fi
    
    # Enable our site
    ln -sf "$SITES_AVAILABLE/$CONFIG_NAME" "$SITES_ENABLED/"
    log "Site enabled"
}

test_and_reload() {
    log "Testing nginx configuration..."
    
    if nginx -t; then
        log "✅ Nginx configuration is valid"
        
        log "Reloading nginx..."
        systemctl reload nginx
        log "✅ Nginx reloaded successfully"
    else
        log "❌ Nginx configuration has errors"
        log "Configuration file: $SITES_AVAILABLE/$CONFIG_NAME"
        exit 1
    fi
}

show_results() {
    log "SSL Configuration Complete! 🎉"
    echo ""
    echo "======================================"
    echo "Nginx SSL Configuration Summary"
    echo "======================================"
    echo ""
    echo "🌐 Your site is now available at:"
    echo "   https://$DOMAIN"
    echo ""
    echo "🔐 Multi-tenant subdomains:"
    echo "   https://tenant1.$DOMAIN"
    echo "   https://tenant2.$DOMAIN"
    echo "   https://any-name.$DOMAIN"
    echo ""
    echo "🔗 API endpoints:"
    echo "   https://$DOMAIN/api/health"
    echo "   https://$DOMAIN/api/"
    echo ""
    echo "🔒 SSL Features enabled:"
    echo "   ✅ HTTP to HTTPS redirect"
    echo "   ✅ SSL/TLS encryption"
    echo "   ✅ Security headers"
    echo "   ✅ Wildcard certificate support"
    echo "   ✅ Multi-tenant routing"
    echo ""
    echo "📝 Configuration file:"
    echo "   $SITES_AVAILABLE/$CONFIG_NAME"
    echo ""
    echo "🔄 Auto-renewal:"
    echo "   SSL certificates will auto-renew via cron/systemd"
    echo "======================================"
}

# Main execution
main() {
    log "Starting Nginx SSL configuration for $DOMAIN"
    
    check_prerequisites
    create_nginx_config
    enable_site
    test_and_reload
    show_results
}

# Handle command line arguments
case "${1:-setup}" in
    "setup"|"configure")
        main
        ;;
    "test")
        nginx -t
        ;;
    "reload")
        systemctl reload nginx
        ;;
    "status")
        systemctl status nginx
        ;;
    *)
        echo "Nginx SSL Configuration Script"
        echo "============================="
        echo ""
        echo "Usage: $0 [command]"
        echo ""
        echo "Commands:"
        echo "  setup      Setup SSL configuration (default)"
        echo "  test       Test nginx configuration"
        echo "  reload     Reload nginx"
        echo "  status     Show nginx status"
        echo ""
        echo "Environment variables:"
        echo "  DOMAIN           Domain name (default: dev.uggla.uamils.com)"
        echo "  BACKEND_PORT     Backend port (default: 3002)"
        echo "  FRONTEND_PORT    Frontend port (default: 3001)"
        ;;
esac