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;
    
    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1000;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/javascript
        application/xml+rss
        application/json;
    
    # Rate limiting
    limit_req_zone $binary_remote_addr zone=api:10m rate=10r/s;
    limit_req_zone $binary_remote_addr zone=uploads:10m rate=2r/s;
    
    upstream backend {
        server api:8000;
    }
    
    server {
        listen 80;
        server_name localhost;
        
        # 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;
        
        # API routes
        location /api/ {
            limit_req zone=api burst=20 nodelay;
            
            proxy_pass http://backend;
            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
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            
            # Timeouts
            proxy_connect_timeout 60s;
            proxy_send_timeout 60s;
            proxy_read_timeout 60s;
            
            # File upload size
            client_max_body_size 500M;
        }
        
        # WebSocket routes
        location /api/v1/ws {
            proxy_pass http://backend;
            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;
        }
        
        # File uploads with special rate limiting
        location /api/v1/files/upload {
            limit_req zone=uploads burst=5 nodelay;
            
            proxy_pass http://backend;
            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;
            
            # Large file upload settings
            client_max_body_size 1G;
            proxy_connect_timeout 300s;
            proxy_send_timeout 300s;
            proxy_read_timeout 300s;
        }
        
        # Frontend static files
        location / {
            root /usr/share/nginx/html;
            try_files $uri $uri/ /index.html;
            
            # Cache static assets
            location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
                expires 1y;
                add_header Cache-Control "public, immutable";
            }
            
            # Don't cache HTML files
            location ~* \.html$ {
                expires -1;
                add_header Cache-Control "no-cache, no-store, must-revalidate";
            }
        }
        
        # Health check endpoint
        location /health {
            access_log off;
            return 200 "OK\n";
            add_header Content-Type text/plain;
        }
    }
}