package goblocks

import (
	"net/http"
	"slices"
)

type Middleware func(http.Handler) http.Handler

type Router struct {
	globalChain []Middleware
	routeChain  []Middleware
	isSub       bool
	*http.ServeMux
}

func newRouter() *Router {
	return &Router{ServeMux: http.NewServeMux()}
}

func (r *Router) Use(mw ...Middleware) {
	if r.isSub {
		r.routeChain = append(r.routeChain, mw...)
	} else {
		r.globalChain = append(r.globalChain, mw...)
	}
}

func (r *Router) Group(fn func(r *Router)) {
	sub := &Router{
		ServeMux:   r.ServeMux,
		routeChain: slices.Clone(r.routeChain),
		isSub:      true,
	}
	fn(sub)
}

func (r *Router) HandleFunc(pattern string, h http.HandlerFunc) {
	r.Handle(pattern, h)
}

func (r *Router) Handle(pattern string, h http.Handler) {
	chain := slices.Clone(r.routeChain)
	slices.Reverse(chain)
	for _, mw := range chain {
		h = mw(h)
	}
	r.ServeMux.Handle(pattern, h)
}

func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	h := http.Handler(r.ServeMux)
	chain := slices.Clone(r.globalChain)
	slices.Reverse(chain)
	for _, mw := range chain {
		h = mw(h)
	}
	h.ServeHTTP(w, req)
}