package handlerlog

import (
	"context"
	"net/http"
)

type ctxKey int

var (
	key ctxKey = 0
)

func FindHandler(mux *http.ServeMux) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			ctx := r.Context()
			if _, pattern := mux.Handler(r); pattern != "" {
				ctx = context.WithValue(ctx, key, pattern)
			}

			next.ServeHTTP(w, r.WithContext(ctx))
		})
	}
}

func Pattern(r *http.Request) (string, bool) {
	pattern, ok := r.Context().Value(key).(string)
	return pattern, ok
}