upstream fastapi_backend {
    server legal-dashboard:8000;
}

server {
    listen 80;
    server_name localhost;
    client_max_body_size 100M;
    
    # 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 "no-referrer-when-downgrade" always;
    add_header Content-Security-Policy "default-src 'self' http: https: data: blob: 'unsafe-inline'" always;

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_proxied expired no-cache no-store private must-revalidate auth;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/javascript
        application/xml+rss
        application/json;

    # Static files
    location /static/ {
        alias /usr/share/nginx/html/static/;
        expires 1y;
        add_header Cache-Control "public, immutable";
        
        # Try to serve file directly, fallback to FastAPI
        try_files $uri $uri/ @fastapi;
    }

    # API routes
    location /api/ {
        proxy_pass http://fastapi_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;
    }

    # Health check
    location /health {
        proxy_pass http://fastapi_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;
    }

    # Docs and admin routes
    location ~ ^/(docs|redoc|openapi\.json) {
        proxy_pass http://fastapi_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;
    }

    # Root and HTML files
    location / {
        # Try static file first, then proxy to FastAPI
        try_files $uri $uri/ @fastapi;
    }

    # FastAPI fallback
    location @fastapi {
        proxy_pass http://fastapi_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;
        
        # Handle large uploads
        proxy_request_buffering off;
        proxy_buffering off;
    }

    # Error pages
    error_page 404 /static/404.html;
    error_page 500 502 503 504 /static/50x.html;

    # Logging
    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;
}

# HTTPS server (uncomment and configure for production)
# server {
#     listen 443 ssl http2;
#     server_name localhost;
#     
#     ssl_certificate /etc/nginx/ssl/cert.pem;
#     ssl_certificate_key /etc/nginx/ssl/key.pem;
#     
#     # SSL configuration
#     ssl_protocols TLSv1.2 TLSv1.3;
#     ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384;
#     ssl_prefer_server_ciphers off;
#     
#     # Include the same location blocks as above
#     include /etc/nginx/conf.d/common-locations.conf;
# }