package web

import (
	"net/http"
	"net/rpc"
	"strings"

	"github.com/alexedwards/scs"
)

// GRPCMiddleware allows a HTTP2 Server to also serve GRPC at the same port.
// Note that a valid certificate is needed, as HTTP2 requires TLS.
func GRPCMiddleware(rpcServer *rpc.Server) func(next http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			ct := r.Header.Get("Content-Type")
			if r.ProtoMajor == 2 && strings.Contains(ct, "application/grpc") {
				rpcServer.ServeHTTP(w, r)
			} else {
				next.ServeHTTP(w, r)
			}
		})
	}
}

// requireLogin makes sure a user is logged in, prior to access
// to a certain ressource.
func requireLogin(sess *scs.Session) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		handler := func(w http.ResponseWriter, r *http.Request) {
			if sess.GetString(r.Context(), SessKeyUserID) == "" {
				sess.Put(r.Context(), SessKeyNext, r.RequestURI)
				http.Redirect(w, r, "/login", http.StatusFound)
				return
			}
			next.ServeHTTP(w, r)
			return
		}

		return http.HandlerFunc(handler)
	}
}