---
# nginx.conf
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 settings
    sendfile        on;
    tcp_nopush      on;
    tcp_nodelay     on;
    keepalive_timeout  65;
    client_max_body_size 100M;

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

    # Rate limiting
    limit_req_zone $binary_remote_addr zone=upload:10m rate=10r/m;
    limit_req_zone $binary_remote_addr zone=api:10m rate=60r/m;

    upstream pdf_summarizer_backend {
        server pdf-summarizer-api:8000 max_fails=3 fail_timeout=30s;
    }

    server {
        listen 80;
        server_name localhost;
        
        # Security headers
        add_header X-Frame-Options DENY;
        add_header X-Content-Type-Options nosniff;
        add_header X-XSS-Protection "1; mode=block";
        add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload";

        # Frontend
        location / {
            root /usr/share/nginx/html;
            index index.html;
            try_files $uri $uri/ /index.html;
        }

        # API endpoints
        location /api/ {
            limit_req zone=api burst=20 nodelay;
            
            proxy_pass http://pdf_summarizer_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;
            
            # Timeouts
            proxy_connect_timeout 60s;
            proxy_send_timeout 60s;
            proxy_read_timeout 300s;
        }

        # Upload endpoint with special rate limiting
        location /api/upload {
            limit_req zone=upload burst=5 nodelay;
            
            proxy_pass http://pdf_summarizer_backend/upload;
            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;
            
            # Extended timeouts for uploads
            proxy_connect_timeout 60s;
            proxy_send_timeout 300s;
            proxy_read_timeout 300s;
            
            client_max_body_size 100M;
        }

        # Health check
        location /health {
            proxy_pass http://pdf_summarizer_backend/health;
            access_log off;
        }

        # Static files caching
        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
            expires 1y;
            add_header Cache-Control "public, immutable";
        }
    }
}