package main

import (
	"context"
	"errors"
	"flag"
	"fmt"
	"net/http"
	"strings"

	"maunium.net/go/mautrix"
	"maunium.net/go/mautrix/id"
)

func main() {
	address := flag.String("address", "127.0.0.1:8080", "address:port to listen on")
	username := flag.String("username", "", "matrix username")
	password := flag.String("password", "", "matrix password")
	homeserver := flag.String("homeserver", "", "matrix homeserver URL")
	flag.Parse()

	if *username == "" {
		fmt.Println("empty username")
		return
	}

	if *password == "" {
		fmt.Println("empty password")
		return
	}

	if *homeserver == "" {
		fmt.Println("empty homeserver")
		return
	}

	fmt.Printf("logging in as %s on %s\n", *username, *homeserver)
	client, err := loginMatrix(*username, *password, *homeserver)
	if err != nil {
		fmt.Println(err)
		return
	}

	fmt.Printf("starting jmap on %s\n", *address)

	http.HandleFunc("/avatar/{mxId}", func(w http.ResponseWriter, r *http.Request) {
		mxId := r.PathValue("mxId")
		if !strings.HasPrefix(mxId, "@") {
			mxId = "@" + mxId
		}
		avatar, err := getMatrixUserAvatar(r.Context(), client, mxId)
		if err != nil {
			fmt.Printf("bad request for %s error %s\n", mxId, err)
			w.WriteHeader(http.StatusInternalServerError)
			return
		}
		fmt.Printf("ok request for %s\n", mxId)
		w.Write(avatar)
	})
	http.ListenAndServe(*address, nil)
}

func loginMatrix(mxId string, password string, homeserverURL string) (client *mautrix.Client, err error) {
	client, err = mautrix.NewClient(homeserverURL, id.UserID(mxId), "")
	if err != nil {
		return nil, err
	}
	_, err = client.Login(context.Background(), &mautrix.ReqLogin{
		Type: mautrix.AuthTypePassword,
		Identifier: mautrix.UserIdentifier{
			Type: mautrix.IdentifierTypeUser,
			User: mxId,
		},
		Password:         password,
		StoreCredentials: true,
	})
	if err != nil {
		return nil, err
	}
	return client, nil
}

func getMatrixUserAvatar(ctx context.Context, client *mautrix.Client, mxId string) (avatar []byte, err error) {
	profile, err := client.GetProfile(ctx, id.UserID(mxId))
	if err != nil {
		return nil, err
	}
	if profile.AvatarURL.IsEmpty() {
		return nil, errors.New("no avatar")
	}
	avatar, err = client.DownloadBytes(ctx, profile.AvatarURL)
	if err != nil {
		return nil, err
	}
	return avatar, nil
}