import io.github.resilience4j.ratelimiter.RateLimiter;
import io.github.resilience4j.ratelimiter.RequestNotPermitted;
import io.vavr.control.Try;
import jakarta.servlet.*;
import jakarta.servlet.http.HttpServletResponse;
import lombok.RequiredArgsConstructor;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import java.io.IOException;

@RequiredArgsConstructor
@Component
@Slf4j
public class RateLimiterServlet implements Filter {

    private final RateLimiter rateLimiter;

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        try {
            Try.runRunnable(() -> RateLimiter.decorateConsumer(rateLimiter, 1, unused -> chain(servletRequest, servletResponse, filterChain)).accept(null)).get();
        } catch (RequestNotPermitted rnp) {
            log.info("2 requests per second is allowed");
            ((HttpServletResponse) servletResponse).setStatus(429);
        }
    }

    @SneakyThrows
    private void chain(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) {
        filterChain.doFilter(servletRequest, servletResponse);
    }

}