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

events {
    worker_connections 1024;
}

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

    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;
    sendfile on;
    keepalive_timeout 65;

    # Rate limiting
    limit_req_zone $binary_remote_addr zone=api:10m rate=30r/m;
    limit_req_zone $binary_remote_addr zone=auth:10m rate=10r/m;

    # Upstream services
    upstream backend {
        server backend:8000;
    }

    upstream frontend {
        server frontend:80;
    }

    # HTTP → HTTPS redirect
    server {
        listen 80;
        server_name _;
        return 301 https://$host$request_uri;
    }

    server {
        listen 443 ssl http2;
        server_name _;

        ssl_certificate /etc/nginx/certs/server.crt;
        ssl_certificate_key /etc/nginx/certs/server.key;
        ssl_protocols TLSv1.2 TLSv1.3;
        ssl_ciphers HIGH:!aNULL:!MD5;
        ssl_prefer_server_ciphers on;
        ssl_session_cache shared:SSL:10m;
        ssl_session_timeout 10m;

        # Security headers
        add_header X-Frame-Options DENY always;
        add_header X-Content-Type-Options nosniff always;
        add_header X-XSS-Protection "1; mode=block" always;
        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
        add_header Referrer-Policy "strict-origin-when-cross-origin" always;

        client_max_body_size 10M;

        # 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;
            proxy_read_timeout 60s;
        }

        # Auth endpoints — stricter rate limiting
        location /api/v1/auth/ {
            limit_req zone=auth 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;
        }

        # API docs (disable in production)
        location /docs {
            return 404;
        }

        # Web frontend
        location / {
            proxy_pass http://frontend;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
        }
    }
}