Only send expiring DMs to compatible relays

3 files changed, 37 insertions, 5 deletions

diff --git a/src/locales/en.json b/src/locales/en.json
index 427c8d96..869a6beb 100644
--- a/src/locales/en.json
+++ b/src/locales/en.json
@@ -97,6 +97,7 @@
 		"recipientMsg": "You are sending nostr messages to [R].",
 		"sendMessage": "Send Message",
 		"expiry": "Enable message expiry",
+		"cantSendExpiring": "None of [R]'s DM relays support message expiry.  You can't send expiring messages to them.",
 		"fadedWarning": "To avoid metadata leaks, messages expire at a random time up to 2 days after you specify; each message has its own random expiry time.  Messages which appear faded are close to expiring; nearby messages may be missing.",
 		"days": "days",
 		"relaysNotFound": "Could not find [R]’s DM relays.",
diff --git a/src/locales/fr.json b/src/locales/fr.json
index 4a096420..d8533bd7 100644
--- a/src/locales/fr.json
+++ b/src/locales/fr.json
@@ -29,6 +29,7 @@
 		"recipientMsg": "Vous envoyez messages nostr à [R].",
 		"sendMessage": "Envoyez Message",
 		"expiry": "Expirez messages",
+		"cantSendExpiring": "Aucun des relais de [R] expirent les messages expirants.  Vous ne pouvez pas leur envoyer des messages expirants.",
 		"fadedWarning": "Pour protéger vos métadonées, vos messages expirent à un temps randomée au maximum 2 jours après la date que vous spécifiez; chaque message a son propre temps d’expiration randomée.  Les messages qui semble faibles sont proche à expirer; les autres messages autours pouvait avoir déjà disparu.",
 		"days": "jours",
 		"relaysNotFound": "Ne pouvait pas trouvez les relais MD de [R].",
diff --git a/src/routes/(app)/dm/[recipient]/+page.svelte b/src/routes/(app)/dm/[recipient]/+page.svelte
index 443119fe..17a8ad23 100644
--- a/src/routes/(app)/dm/[recipient]/+page.svelte
+++ b/src/routes/(app)/dm/[recipient]/+page.svelte
@@ -2,6 +2,7 @@
  import { tick } from "svelte";
  import Icon from "$comp/Icon.svelte";
  import { hexToBytes, bytesToHex } from '@noble/hashes/utils';
+ import { fetchRelayInformation } from 'nostr-tools/nip11';
  import * as toolsnip17 from 'nostr-tools/nip17';
  import { SimplePool } from 'nostr-tools/pool';
  import * as libnip17 from '$lib/nip17';
@@ -25,6 +26,7 @@
  let expiryEnabled = $state(false);
  let expiryDays = $state(7);
  let canSend = $state(false);
+ let canSendExpiring = $state(false);
 
  const appendMultimap = (map: Map, key: string, value: object) => {
    if (map.has(key)) {
@@ -66,6 +68,20 @@
    return relays;
  }
 
+ // Accepts a list of relays, and returns a list of the relays that support all the provided NIPs.
+ const relaysSupporting = async (relays: string[], nips: number[]) => {
+   let supportingRelays = [];
+
+   for (const relay of relays) {
+     const relayInfo = await fetchRelayInformation(relay);
+     if (nips.every(relay => relayInfo.supported_nips.includes(relay))) {
+       supportingRelays.push(relay);
+     }
+   }
+
+   return supportingRelays;
+ }
+
  const expired = (event: object) => {
    for (const tag of event.tags) {
      if (tag[0] == "expiration") {
@@ -120,8 +136,11 @@
    relayWarningShown = false;
    loadEvents(relays);
  });
- getPreferredRelays(recipient.pubkey)
-   .then((relays) => canSend = relays && relays.length > 0);
+ getPreferredRelays(recipient.pubkey).then((relays) => {
+   canSend = relays && relays.length > 0;
+   relaysSupporting(relays, [40])
+     .then((supporting) => canSendExpiring = supporting.length > 0);
+ });
 
  const sendMessage = async (message: string) => {
    const expiry = expiryEnabled ? expiryDays : null;
@@ -139,10 +158,18 @@
        message, sk, recipient.pubkey, user.pubkey, expiry);
    }
 
-   const recipientRelays = await getPreferredRelays(recipient.pubkey);
+   let recipientRelays = await getPreferredRelays(recipient.pubkey);
+   if (expiryEnabled) {
+     recipientRelays = relaysSupporting(recipientRelays, [40]);
+   }
    const p1 = Promise.any(pool.publish(recipientRelays, event1));
-   const senderRelays = await getPreferredRelays(user.pubkey);
+
+   let senderRelays = await getPreferredRelays(user.pubkey);
+   if (expiryEnabled) {
+     senderRelays = relaysSupporting(senderRelays, [40]);
+   }
    const p2 = Promise.any(pool.publish(senderRelays, event2));
+
    await Promise.all([p1, p2]);
    getPreferredRelays(user.pubkey).then(loadEvents);
  }
@@ -224,8 +251,11 @@
 
         <textarea id="message-contents" bind:value={text}></textarea>
 
-        <input type="checkbox" class="tiny" bind:checked={expiryEnabled}>{$t("dm.expiry")}: <input type="number" class="short" bind:value={expiryDays} disabled={!expiryEnabled} min="1" step="1" max="99999"> {$t("dm.days")}.
+        <input type="checkbox" class="tiny" bind:checked={expiryEnabled} disabled={!canSendExpiring}>{$t("dm.expiry")}: <input type="number" class="short" bind:value={expiryDays} disabled={!expiryEnabled} min="1" step="1" max="99999"> {$t("dm.days")}.
         <p class="expiring">{$t("dm.fadedWarning")}</p>
+        {#if canSend && !canSendExpiring}
+            <p class="warning"><em>{$t("dm.cantSendExpiring").replace("[R]", recipient.username)}</em></p>
+        {/if}
 
         <input id="send-message" type="button" class="btn" disabled={!canSend} value={canSend ? $t("dm.sendMessage") : $t("dm.relaysNotFound").replace("[R]", recipient.username)} on:click={async () => sendMessage(text)}>
         {#if relayWarningShown}