package main

import (
	"encoding/json"
	"github.com/gorilla/mux"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
	"regexp"
	"willnorris.com/go/webmention"
)

func Serve() {

	webfingerHandler := func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("content-type", "application/jrd+json; charset=utf-8")
		name := r.URL.Query().Get("resource") // should be something like acct:user@example.com
		urlBaseUrl, _ := url.Parse(baseURL)
		re := regexp.MustCompile(`^acct:(.*)@` + regexp.QuoteMeta(urlBaseUrl.Host) + `$`)
		name = re.ReplaceAllString(name, "$1")
		actor := actors[name]
		// error out if this actor does not exist
		if actor == nil {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		responseMap := make(map[string]interface{})
		responseMap["subject"] = "acct:" + actor.Name + "@" + urlBaseUrl.Host
		// links is a json array with a single element
		var links [1]map[string]string
		link1 := make(map[string]string)
		link1["rel"] = "self"
		link1["type"] = ContentTypeAs2
		link1["href"] = actor.iri
		links[0] = link1
		responseMap["links"] = links
		response, _ := json.Marshal(responseMap)
		_, _ = w.Write(response)
	}

	inboxHandler := func(w http.ResponseWriter, r *http.Request) {
		b, err := ioutil.ReadAll(r.Body)
		if err != nil {
			panic(err)
		}
		activity := make(map[string]interface{})
		err = json.Unmarshal(b, &activity)
		if err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			return
		}
		if activity["type"] == "Follow" {
			actor := actors[mux.Vars(r)["actor"]]
			// error out if this actor does not exist
			if actor == nil {
				w.WriteHeader(http.StatusNotFound)
				return
			}
			actor.Accept(activity)
		} else if activity["type"] == "Undo" {
			// TODO: Implement unfollow
		} else if activity["type"] == "Create" {
			object, ok := activity["object"].(map[string]interface{})
			if ok {
				inReplyTo, ok := object["inReplyTo"].(string)
				id, ok2 := object["id"].(string)
				if ok && ok2 && len(inReplyTo) > 0 && len(id) > 0 {
					webmentionClient := webmention.New(nil)
					endpoint, err := webmentionClient.DiscoverEndpoint(inReplyTo)
					if err != nil || len(endpoint) < 1 {
						return
					}
					_, err = webmentionClient.SendWebmention(endpoint, id, inReplyTo)
					if err != nil {
						log.Println("Sending webmention to " + inReplyTo + " failed")
						return
					}
					log.Println("Sent webmention to " + inReplyTo)
				}
			}
		}
	}

	// Add the handlers to a HTTP server
	gorilla := mux.NewRouter()
	gorilla.HandleFunc("/.well-known/webfinger", webfingerHandler)
	gorilla.HandleFunc("/{actor}/inbox", inboxHandler)
	gorilla.HandleFunc("/{actor}/inbox/", inboxHandler)
	http.Handle("/", gorilla)

	log.Fatal(http.ListenAndServe(":8081", nil))
}