From 4c554c91a6cb983c5af953e4728594fd4a76ca7c Mon Sep 17 00:00:00 2001
From: Danny Morabito <danny@arx-ccn.com>
Date: Mon, 17 Mar 2025 19:14:49 +0100
Subject: [PATCH] Implement Replaceable and Addressable Events

---
 index.ts | 97 +++++++++++++++++++++++++++++++++++++++++++++++---------
 utils.ts | 26 +++++++++++++++
 2 files changed, 108 insertions(+), 15 deletions(-)

diff --git a/index.ts b/index.ts
index 7cfb67a..71d54db 100644
--- a/index.ts
+++ b/index.ts
@@ -7,9 +7,12 @@ import type {
 import {
   getCCNPrivateKey,
   getCCNPubkey,
+  isAddressableEvent,
   isArray,
   isLocalhost,
+  isReplaceableEvent,
   isValidJSON,
+  parseATagQuery,
   randomTimeUpTo2DaysInThePast,
 } from "./utils.ts";
 import * as nostrTools from "@nostr/tools";
@@ -171,6 +174,36 @@ function addEventToDb(
   if (existingEvent) throw new EventAlreadyExistsException();
   try {
     db.run("BEGIN TRANSACTION");
+    if (isReplaceableEvent(decryptedEvent.kind)) {
+      sql`
+        DELETE FROM events 
+        WHERE kind = ${decryptedEvent.kind}
+        AND pubkey = ${decryptedEvent.pubkey}
+        AND created_at < ${decryptedEvent.created_at}
+      `(db);
+    }
+
+    if (isAddressableEvent(decryptedEvent.kind)) {
+      const dTag = decryptedEvent.tags.find((tag) => tag[0] === "d")?.[1];
+      if (dTag) {
+        sql`
+          DELETE FROM events 
+          WHERE kind = ${decryptedEvent.kind}
+          AND pubkey = ${decryptedEvent.pubkey}
+          AND created_at < ${decryptedEvent.created_at}
+          AND id IN (
+            SELECT event_id FROM event_tags 
+            WHERE tag_name = 'd' 
+            AND tag_id IN (
+              SELECT tag_id FROM event_tags_values
+              WHERE value_position = 1
+              AND value = ${dTag}
+            )
+          )
+        `(db);
+      }
+    }
+
     sql`
     INSERT INTO events (id, original_id, pubkey, created_at, kind, content, sig, first_seen) VALUES (
       ${decryptedEvent.id},
@@ -431,22 +464,56 @@ function handleRequest(connection: UserConnection, request: NostrClientREQ) {
           const uniqueValues = [...new Set(value)];
           query = mixQuery(query, sqlPartial`(`);
           for (let k = 0; k < uniqueValues.length; k++) {
-            const value = uniqueValues[k] as string;
+            const tagValue = uniqueValues[k] as string;
+            if (tag === "a") {
+              const aTagInfo = parseATagQuery(tagValue);
+
+              if (aTagInfo.dTag && aTagInfo.dTag !== "") {
+                // Addressable event reference
+                query = mixQuery(
+                  query,
+                  sqlPartial`id IN (
+                    SELECT e.id
+                    FROM events e
+                    JOIN event_tags t ON e.id = t.event_id
+                    JOIN event_tags_values v ON t.tag_id = v.tag_id
+                    WHERE e.kind = ${aTagInfo.kind}
+                    AND e.pubkey = ${aTagInfo.pubkey}
+                    AND t.tag_name = 'd'
+                    AND v.value_position = 1
+                    AND v.value = ${aTagInfo.dTag}
+                  )`,
+                );
+              } else {
+                // Replaceable event reference
+                query = mixQuery(
+                  query,
+                  sqlPartial`id IN (
+                    SELECT id
+                    FROM events
+                    WHERE kind = ${aTagInfo.kind}
+                    AND pubkey = ${aTagInfo.pubkey}
+                  )`,
+                );
+              }
+            } else {
+              // Regular tag handling (unchanged)
+              query = mixQuery(
+                query,
+                sqlPartial`id IN (
+                  SELECT t.event_id
+                  FROM event_tags t
+                  WHERE t.tag_name = ${tag}
+                  AND t.tag_id IN (
+                    SELECT v.tag_id 
+                    FROM event_tags_values v
+                    WHERE v.value_position = 1
+                    AND v.value = ${tagValue}
+                  )
+                )`,
+              );
+            }
 
-            query = mixQuery(
-              query,
-              sqlPartial`id IN (
-                SELECT t.event_id
-                FROM event_tags t
-                WHERE t.tag_name = ${tag}
-                AND t.tag_id IN (
-                  SELECT v.tag_id 
-                  FROM event_tags_values v
-                  WHERE v.value_position = 1
-                  AND v.value = ${value}
-                )
-              )`,
-            );
             if (k < uniqueValues.length - 1) {
               query = mixQuery(query, sqlPartial`OR`);
             }
diff --git a/utils.ts b/utils.ts
index 1ec0095..5c7c5c6 100644
--- a/utils.ts
+++ b/utils.ts
@@ -67,3 +67,29 @@ export async function getCCNPrivateKey(): Promise<Uint8Array> {
   );
   return decryptUint8Array(decodeBase64(encryptedPrivateKey), encryptionKey);
 }
+
+export function isReplaceableEvent(kind: number): boolean {
+  return (kind >= 10000 && kind < 20000) || kind === 0 || kind === 3;
+}
+
+export function isAddressableEvent(kind: number): boolean {
+  return kind >= 30000 && kind < 40000;
+}
+
+export function isRegularEvent(kind: number): boolean {
+  return (kind >= 1000 && kind < 10000) ||
+    (kind >= 4 && kind < 45) ||
+    kind === 1 ||
+    kind === 2;
+}
+
+export function parseATagQuery(aTagValue: string): { kind: number, pubkey: string, dTag?: string } {
+  const parts = aTagValue.split(':');
+  if (parts.length < 2) return { kind: 0, pubkey: '' };
+
+  return {
+    kind: parseInt(parts[0], 10),
+    pubkey: parts[1],
+    dTag: parts.length > 2 ? parts[2] : undefined
+  };
+}