package utils

import (
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"
)

var cacheETag = strconv.FormatInt(time.Now().Unix(), 16)

func RequestKiller(rw http.ResponseWriter) {
	if hi, ok := rw.(http.Hijacker); ok {
		conn, _, err := hi.Hijack()
		if err == nil {
			_ = conn.Close()
		}
	}
}

func GetBearerToken(req *http.Request) string {
	auth := req.Header.Get("Authorization")
	if strings.HasPrefix(strings.ToLower(auth), "bearer ") {
		return auth[len("bearer "):]
	}
	return ""
}

func CachedPage(cb func(rw http.ResponseWriter, req *http.Request)) func(rw http.ResponseWriter, req *http.Request) {
	return func(rw http.ResponseWriter, req *http.Request) {
		if req.Header.Get("If-None-Match") == req.RequestURI+"."+cacheETag {
			rw.WriteHeader(http.StatusNotModified)
			return
		}
		rw.Header().Set("Etag", req.RequestURI+"."+cacheETag)
		cb(rw, req)
	}
}

// CloneURL is copied from https://github.com/golang/go/blob/go1.19/src/net/http/clone.go#L22
func CloneURL(u *url.URL) *url.URL {
	if u == nil {
		return nil
	}
	u2 := new(url.URL)
	*u2 = *u
	if u.User != nil {
		u2.User = new(url.Userinfo)
		*u2.User = *u.User
	}
	return u2
}