package middleware

import (
	"net/http"

	"source.toby3d.me/toby3d/home/internal/domain"
	"source.toby3d.me/toby3d/home/internal/server"
	"source.toby3d.me/toby3d/home/internal/urlutil"
)

type HeaderConfig struct {
	Skipper  Skipper
	Serverer server.UseCase
}

func Header(config HeaderConfig) Interceptor {
	if config.Skipper == nil {
		config.Skipper = DefaultSkipper
	}

	if config.Serverer == nil {
		panic("middleware: header: Serverer is nil")
	}

	return func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
		if config.Skipper(r) {
			next(w, r)

			return
		}

		lang, path := domain.LanguageUnd, r.URL.Path
		if head, tail := urlutil.ShiftPath(r.URL.Path); head != "" {
			if lang = domain.NewLanguage(head); lang != domain.LanguageUnd {
				path = tail
			}
		}

		server, err := config.Serverer.Do(r.Context(), lang)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)

			return
		}

		for _, header := range server.Headers.Match(path) {
			for k, v := range header.Values {
				w.Header().Add(k, v)
			}
		}

		next(w, r)
	}
}