# Nginx Configuration for Document Translation API
# Production-ready with SSL, caching, and security headers

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
    worker_connections 1024;
    use epoll;
    multi_accept on;
}

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

    # Logging format
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for" '
                    'rt=$request_time uct="$upstream_connect_time" '
                    'uht="$upstream_header_time" urt="$upstream_response_time"';

    access_log /var/log/nginx/access.log main;

    # Performance optimizations
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;

    # 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/xml application/rss+xml application/atom+xml image/svg+xml;

    # File upload size (for document translation)
    client_max_body_size 100M;
    client_body_timeout 300s;
    client_header_timeout 60s;

    # Proxy settings
    proxy_connect_timeout 60s;
    proxy_send_timeout 300s;
    proxy_read_timeout 300s;
    proxy_buffer_size 128k;
    proxy_buffers 4 256k;
    proxy_busy_buffers_size 256k;

    # Rate limiting zones
    limit_req_zone $binary_remote_addr zone=api_limit:10m rate=10r/s;
    limit_req_zone $binary_remote_addr zone=upload_limit:10m rate=2r/s;
    limit_conn_zone $binary_remote_addr zone=conn_limit:10m;

    # Upstream definitions
    upstream backend {
        server backend:8000;
        keepalive 32;
    }

    upstream frontend {
        server frontend:3000;
        keepalive 32;
    }

    # Include additional configs
    include /etc/nginx/conf.d/*.conf;
}