From 02e54e4dbfd10ff7e760c13912ef655ee911cad9 Mon Sep 17 00:00:00 2001
From: "Dr. Tobias Baur" <tobias_baur@yahoo.com>
Date: Fri, 10 Mar 2023 15:34:31 +0100
Subject: [PATCH] Download Nostr Profile picture to show in some wallets (non
 zaps)

---
 invoice.go | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 nostr.go   | 44 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+), 2 deletions(-)

diff --git a/invoice.go b/invoice.go
index d3d5853..2378184 100644
--- a/invoice.go
+++ b/invoice.go
@@ -1,12 +1,18 @@
 package main
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
+	"image"
+	"image/jpeg"
+	"io/ioutil"
+	"net/http"
 	"strconv"
 	"time"
 
 	"github.com/nbd-wtf/go-nostr"
+	"github.com/nfnt/resize"
 
 	"github.com/fiatjaf/go-lnurl"
 	// "github.com/fiatjaf/makeinvoice"
@@ -14,11 +20,52 @@ import (
 
 func metaData(params *Params) lnurl.Metadata {
 
-	//addImageToMetaData(w.telegram, &metadata, username, user.Telegram)
-	return lnurl.Metadata{
+	metadata := lnurl.Metadata{
 		Description:      fmt.Sprintf("Pay to %s@%s", params.Name, params.Domain),
 		LightningAddress: fmt.Sprintf("%s@%s", params.Name, params.Domain),
 	}
+
+	NostrProfile, _ := GetNostrProfileMetaData(params.Npub)
+
+	addImageToMetaData(&metadata, NostrProfile.Picture)
+	return metadata
+
+}
+
+// addImageMetaData add images an image to the LNURL metadata
+func addImageToMetaData(metadata *lnurl.Metadata, imageurl string) {
+
+	picture, _ := DownloadProfilePicture(imageurl)
+	// if err != nil {
+	// 	log.Debug().Str("Downloading profile picture", err.Error()).Msg("Error")
+	// 	return
+	// }
+	metadata.Image.Ext = "jpeg"
+	metadata.Image.DataURI = imageurl
+	metadata.Image.Bytes = picture
+}
+
+func DownloadProfilePicture(url string) ([]byte, error) {
+	res, err := http.Get(url)
+
+	if err != nil {
+		//log.Fatalf("http.Get -> %v", err)
+	}
+	data, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		// log.Fatalf("ioutil.ReadAll -> %v", err)
+	}
+	res.Body.Close()
+	img, _, err := image.Decode(bytes.NewReader(data))
+	if err != nil {
+		return nil, err
+	}
+	// resize image
+	img = resize.Thumbnail(160, 160, img, resize.Lanczos3)
+	buf := new(bytes.Buffer)
+	_ = jpeg.Encode(buf, img, nil)
+	ioutil.WriteFile("test.jpg", buf.Bytes(), 0666)
+	return buf.Bytes(), nil
 }
 
 func makeInvoice(
@@ -29,6 +76,7 @@ func makeInvoice(
 	comment string,
 ) (bolt11 string, err error) {
 	// prepare params
+
 	var backend BackendParams
 	switch params.Kind {
 	case "sparko":
diff --git a/nostr.go b/nostr.go
index e6b41ce..4cf5589 100644
--- a/nostr.go
+++ b/nostr.go
@@ -82,6 +82,50 @@ func handleNip05(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func GetNostrProfileMetaData(npub string) (nostr.ProfileMetadata, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+
+	var metadata *nostr.ProfileMetadata
+	// connect to any relay
+	url := "wss://relay.damus.io"
+	relay, err := nostr.RelayConnect(ctx, url)
+	if err != nil {
+		panic(err)
+	}
+
+	// create filters
+	var filters nostr.Filters
+	if _, v, err := nip19.Decode(npub); err == nil {
+		t := make(map[string][]string)
+		t["p"] = []string{v.(string)}
+		filters = []nostr.Filter{{
+			Authors: []string{v.(string)},
+			Kinds:   []int{0},
+			// limit = 3, get the three most recent notes
+			Limit: 1,
+		}}
+	} else {
+		return *metadata, err
+
+	}
+	sub := relay.Subscribe(ctx, filters)
+	evs := make([]nostr.Event, 0)
+
+	go func() {
+		<-sub.EndOfStoredEvents
+		cancel()
+	}()
+
+	for ev := range sub.Events {
+
+		evs = append(evs, *ev)
+	}
+	metadata, err = nostr.ParseMetadata(evs[0])
+
+	return *metadata, err
+
+}
+
 func publishNostrEvent(ev nostr.Event, relays []string) {
 	pk := s.NostrPrivateKey
 	ev.Sign(pk)