package fastrp

import (
	"context"
	"net"
	"net/http"
	"net/http/httputil"
	"net/url"
	"sync"
)

type FastRP struct {
	rp       *httputil.ReverseProxy
	connPool *sync.Pool
}

func NewRP(network, address string, url *url.URL) *FastRP {
	roundTripper := &http.Transport{
		DialContext: func(_ context.Context, _ string, _ string) (net.Conn, error) {
			return net.Dial(network, address)
		},
		MaxIdleConns: 10,
	}
	frp := &FastRP{
		rp: httputil.NewSingleHostReverseProxy(url),
		connPool: &sync.Pool{
			New: func() any {
				return roundTripper.Clone()
			},
		},
	}
	frp.rp.Transport = frp.connPool.Get().(http.RoundTripper)
	return frp
}

func (frp *FastRP) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	roundTripper := frp.connPool.Get().(http.RoundTripper)
	defer frp.connPool.Put(roundTripper)
	frp.rp.Transport = roundTripper
	frp.rp.ServeHTTP(w, r)
}