package home

import (
	"encoding/json"
	"net/http"

	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
	"github.com/AdguardTeam/golibs/log"
	"github.com/AdguardTeam/urlfilter"
)

var serviceRules map[string][]*urlfilter.NetworkRule // service name -> filtering rules

type svc struct {
	name  string
	rules []string
}

// Keep in sync with:
// client/src/helpers/constants.js
// client/src/components/ui/Icons.js
var serviceRulesArray = []svc{
	{"whatsapp", []string{"||whatsapp.net^"}},
	{"facebook", []string{"||facebook.com^"}},
	{"twitter", []string{"||twitter.com^", "||t.co^", "||twimg.com^"}},
	{"youtube", []string{"||youtube.com^", "||ytimg.com^", "||youtubei.googleapis.com^"}},
	{"messenger", []string{"||fb.com^", "||facebook.com^"}},
	{"twitch", []string{"||twitch.tv^", "||ttvnw.net^"}},
	{"netflix", []string{"||nflxext.com^", "||netflix.com^"}},
	{"instagram", []string{"||instagram.com^"}},
	{"snapchat", []string{"||snapchat.com^"}},
	{"discord", []string{"||discord.gg^", "||discordapp.net^", "||discordapp.com^"}},
	{"ok", []string{"||ok.ru^"}},
	{"skype", []string{"||skype.com^"}},
	{"vk", []string{"||vk.com^"}},
	{"steam", []string{"||steam.com^"}},
	{"epic_games", []string{"||epicgames.com^"}},
	{"reddit", []string{"||reddit.com^", "||redditstatic.com^", "||redditmedia.com^", "||redd.it^"}},
	{"mail_ru", []string{"||mail.ru^"}},
	{"tiktok", []string{
		"||tiktok.com^",
		"||snssdk.com^",
		"||amemv.com^",
		"||toutiao.com^",
		"||ixigua.com^",
		"||pstatp.com^",
		"||ixiguavideo.com^",
		"||toutiaocloud.com^",
		"||toutiaocloud.net^",
		"||bdurl.com^",
		"||bytecdn.cn^",
		"||byteimg.com^",
		"||ixigua.com^",
	}},
}

// convert array to map
func initServices() {
	serviceRules = make(map[string][]*urlfilter.NetworkRule)
	for _, s := range serviceRulesArray {
		rules := []*urlfilter.NetworkRule{}
		for _, text := range s.rules {
			rule, err := urlfilter.NewNetworkRule(text, 0)
			if err != nil {
				log.Error("urlfilter.NewNetworkRule: %s  rule: %s", err, text)
				continue
			}
			rules = append(rules, rule)
		}
		serviceRules[s.name] = rules
	}
}

// ApplyBlockedServices - set blocked services settings for this DNS request
func ApplyBlockedServices(setts *dnsfilter.RequestFilteringSettings, list []string) {
	setts.ServicesRules = []dnsfilter.ServiceEntry{}
	for _, name := range list {
		rules, ok := serviceRules[name]

		if !ok {
			log.Error("unknown service name: %s", name)
			continue
		}

		s := dnsfilter.ServiceEntry{}
		s.Name = name
		s.Rules = rules
		setts.ServicesRules = append(setts.ServicesRules, s)
	}
}

func handleBlockedServicesList(w http.ResponseWriter, r *http.Request) {
	config.RLock()
	list := config.DNS.BlockedServices
	config.RUnlock()

	w.Header().Set("Content-Type", "application/json")
	err := json.NewEncoder(w).Encode(list)
	if err != nil {
		httpError(w, http.StatusInternalServerError, "json.Encode: %s", err)
		return
	}
}

func handleBlockedServicesSet(w http.ResponseWriter, r *http.Request) {
	list := []string{}
	err := json.NewDecoder(r.Body).Decode(&list)
	if err != nil {
		httpError(w, http.StatusBadRequest, "json.Decode: %s", err)
		return
	}

	config.Lock()
	config.DNS.BlockedServices = list
	config.Unlock()

	log.Debug("Updated blocked services list: %d", len(list))

	err = writeAllConfigsAndReloadDNS()
	if err != nil {
		httpError(w, http.StatusBadRequest, "%s", err)
		return
	}

	returnOK(w)
}

// RegisterBlockedServicesHandlers - register HTTP handlers
func RegisterBlockedServicesHandlers() {
	httpRegister(http.MethodGet, "/control/blocked_services/list", handleBlockedServicesList)
	httpRegister(http.MethodPost, "/control/blocked_services/set", handleBlockedServicesSet)
}