From cd7ffb891170c84e44870766fe52e8161ba56c1e Mon Sep 17 00:00:00 2001
From: fiatjaf <fiatjaf@gmail.com>
Date: Tue, 14 Dec 2021 21:56:07 -0300
Subject: [PATCH] add local event filter functions.

---
 filter.js    | 26 ++++++++++++++++++++++++++
 index.js     |  5 ++++-
 package.json |  2 +-
 3 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 filter.js

diff --git a/filter.js b/filter.js
new file mode 100644
index 0000000..c06c709
--- /dev/null
+++ b/filter.js
@@ -0,0 +1,26 @@
+export function matchFilter(filter, event) {
+  if (filter.id && event.id !== filter.id) return false
+  if (filter.kind && event.kind !== filter.kind) return false
+  if (filter.author && event.pubkey !== filter.author) return false
+  if (filter.authors && filter.author.indexOf(event.pubkey) === -1) return false
+  if (
+    filter['#e'] &&
+    event.tags.find(([t, v]) => t === 'e' && v === filter['#e']) === null
+  )
+    return false
+  if (
+    filter['#p'] &&
+    event.tags.find(([t, v]) => t === 'p' && v === filter['#p']) === null
+  )
+    return false
+  if (filter.since && event.created_at <= filter.since) return false
+
+  return true
+}
+
+export function matchFilters(filters, event) {
+  for (let i = 0; i < filters.length; i++) {
+    if (matchFilter(filters[i], event)) return true
+  }
+  return false
+}
diff --git a/index.js b/index.js
index 5bfe865..cdeb0da 100644
--- a/index.js
+++ b/index.js
@@ -7,6 +7,7 @@ import {
   serializeEvent,
   getEventHash
 } from './event'
+import {matchFilter, matchFilters} from './filter'
 import {makeRandom32, sha256, getPublicKey} from './utils'
 
 export {
@@ -19,5 +20,7 @@ export {
   makeRandom32,
   sha256,
   getPublicKey,
-  getBlankEvent
+  getBlankEvent,
+  matchFilter,
+  matchFilters
 }
diff --git a/package.json b/package.json
index 47a4a1b..aabba53 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "nostr-tools",
-  "version": "0.9.1",
+  "version": "0.10.0",
   "description": "Tools for making a Nostr client.",
   "repository": {
     "type": "git",