# Nginx Configuration for Production
# Handles SSL termination, reverse proxy, and security headers

events {
    worker_connections 1024;
}

http {
    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    # Logging
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';

    access_log /var/log/nginx/access.log main;
    error_log /var/log/nginx/error.log warn;

    # Performance
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    client_max_body_size 50M;

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types text/plain text/css text/xml application/json application/javascript application/rss+xml application/atom+xml image/svg+xml;

    # Rate limiting
    limit_req_zone $binary_remote_addr zone=api:10m rate=10r/s;
    limit_req_zone $binary_remote_addr zone=general:10m rate=100r/m;

    # SSL configuration (when certificates are available)
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers off;
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;

    # Frontend - HTTP to HTTPS redirect (when SSL enabled)
    server {
        listen 80;
        server_name _;

        # Certbot challenge
        location /.well-known/acme-challenge/ {
            root /var/www/certbot;
        }

        # Uncomment after SSL setup:
        # return 301 https://$host$request_uri;

        # For now, proxy to frontend
        location / {
            proxy_pass http://frontend:3000;
            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;
        }

        # API routes
        location /api {
            limit_req zone=api burst=20 nodelay;
            proxy_pass http://backend:3001;
            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;
            proxy_read_timeout 86400;
        }

        # WebSocket support
        location /ws {
            proxy_pass http://backend:3001/ws;
            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 uploads
        location /uploads {
            alias /var/www/uploads;
            expires 30d;
            add_header Cache-Control "public, immutable";
        }
    }

    # Frontend - HTTPS (uncomment after SSL setup)
    # server {
    #     listen 443 ssl http2;
    #     server_name your-domain.com;
    #
    #     ssl_certificate /etc/letsencrypt/live/your-domain.com/fullchain.pem;
    #     ssl_certificate_key /etc/letsencrypt/live/your-domain.com/privkey.pem;
    #
    #     # Security headers
    #     add_header X-Frame-Options "SAMEORIGIN" 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;
    #     add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-eval' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self'; connect-src 'self' https:;" always;
    #
    #     location / {
    #         proxy_pass http://frontend:3000;
    #         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;
    #     }
    #
    #     location /api {
    #         limit_req zone=api burst=20 nodelay;
    #         proxy_pass http://backend:3001;
    #         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;
    #         proxy_read_timeout 86400;
    #     }
    #
    #     location /ws {
    #         proxy_pass http://backend:3001/ws;
    #         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;
    #     }
    #
    #     location /uploads {
    #         alias /var/www/uploads;
    #         expires 30d;
    #         add_header Cache-Control "public, immutable";
    #     }
    # }
}