events {
    worker_connections 1024;
}

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

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

    # Gzip
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml;

    # File upload limit (15 MB)
    client_max_body_size 15M;

    # Rate limiting zones
    limit_req_zone $binary_remote_addr zone=api_auth:10m rate=10r/m;
    limit_req_zone $binary_remote_addr zone=api_general:10m rate=60r/m;

    upstream backend {
        server backend:8000;
    }

    upstream frontend {
        server frontend:80;
    }

    server {
        listen 80;
        server_name localhost;

        # Frontend
        location / {
            proxy_pass http://frontend;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

        # Auth API - strict rate limit (10 req/min with burst of 5)
        location /api/v1/auth {
            limit_req zone=api_auth burst=5 nodelay;
            limit_req_status 429;

            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;
        }

        # Backend API - general rate limit (60 req/min with burst of 20)
        location /api {
            limit_req zone=api_general burst=20 nodelay;
            limit_req_status 429;

            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;

            # Timeout for long GPT requests (15 min)
            proxy_read_timeout 900;
            proxy_connect_timeout 900;
            proxy_send_timeout 900;
        }

        # Static files (uploads)
        location /uploads {
            alias /app/uploads;
            expires 30d;
            add_header Cache-Control "public, immutable";
        }

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