From c3b8ad1c283ea10c6d99249278b7d019a7ffb246 Mon Sep 17 00:00:00 2001
From: Alex Gleason <alex@alexgleason.me>
Date: Fri, 7 Apr 2023 21:37:16 -0500
Subject: [PATCH] Scaffold db, handler, query

---
 src/db.ts      |  7 +++++++
 src/deps.ts    |  7 +++----
 src/gossip.ts  | 21 +++++++++++++++++++++
 src/handler.ts | 19 +++++++++++++++++++
 src/query.ts   |  7 +++++++
 src/schema.ts  | 20 +++++++++++++++++++-
 6 files changed, 76 insertions(+), 5 deletions(-)
 create mode 100644 src/db.ts
 create mode 100644 src/gossip.ts
 create mode 100644 src/handler.ts
 create mode 100644 src/query.ts

diff --git a/src/db.ts b/src/db.ts
new file mode 100644
index 0000000..022a952
--- /dev/null
+++ b/src/db.ts
@@ -0,0 +1,7 @@
+import { lmdb } from '@/deps.ts';
+
+const db = lmdb.open('db', {});
+
+const gossipDB = db.openDB('gossip', { dupSort: true });
+
+export { db, gossipDB };
diff --git a/src/deps.ts b/src/deps.ts
index 8385391..edc893a 100644
--- a/src/deps.ts
+++ b/src/deps.ts
@@ -1,7 +1,6 @@
-import { Context, Hono, validator } from 'https://deno.land/x/hono@v3.0.2/mod.ts';
-export { Hono, validator };
+export { type Context, Hono, validator } from 'https://deno.land/x/hono@v3.0.2/mod.ts';
 export { cors } from 'https://deno.land/x/hono@v3.0.2/middleware.ts';
 export { z } from 'https://deno.land/x/zod@v3.20.5/mod.ts';
 export { Author, RelayPool } from 'https://dev.jspm.io/nostr-relaypool@0.5.3';
-export { getEventHash, getPublicKey, nip19, signEvent } from 'npm:nostr-tools@^1.7.4';
-export type { Context };
+export { type Filter, getEventHash, getPublicKey, nip19, signEvent } from 'npm:nostr-tools@^1.7.4';
+export { default as lmdb } from 'npm:lmdb';
diff --git a/src/gossip.ts b/src/gossip.ts
new file mode 100644
index 0000000..7ccb218
--- /dev/null
+++ b/src/gossip.ts
@@ -0,0 +1,21 @@
+import { parseRelay } from './schema.ts';
+
+import type { Event } from './event.ts';
+
+/** Gets relays which pertain to the author from the event. */
+function getAuthorRelays(event: Event): URL[] {
+  const relays: string[] = [];
+
+  switch (event.kind) {
+    case 10002:
+      event.tags.forEach((tag) => tag[0] === 'r' && relays.push(tag[1]));
+      break;
+    case 2:
+      relays.push(event.content);
+      break;
+  }
+
+  return relays.map(parseRelay).filter((r): r is URL => !!r);
+}
+
+export { getAuthorRelays };
diff --git a/src/handler.ts b/src/handler.ts
new file mode 100644
index 0000000..ad75b10
--- /dev/null
+++ b/src/handler.ts
@@ -0,0 +1,19 @@
+import { gossipDB } from '@/db.ts';
+
+import { getAuthorRelays } from './gossip.ts';
+
+import type { Event } from './event.ts';
+
+function handleEvent(event: Event): void {
+  handleRelays(event);
+}
+
+/** Add author relays into the database. */
+function handleRelays(event: Event): Promise<boolean[]> {
+  const relays = getAuthorRelays(event);
+  return Promise.all(
+    relays.map((relay) => gossipDB.put(event.pubkey, relay.toString())),
+  );
+}
+
+export { handleEvent };
diff --git a/src/query.ts b/src/query.ts
new file mode 100644
index 0000000..4b4d062
--- /dev/null
+++ b/src/query.ts
@@ -0,0 +1,7 @@
+import type { Filter } from '@/deps.ts';
+
+function query(_filter: Filter, _relays?: URL[]) {
+  // TODO
+}
+
+export { query };
diff --git a/src/schema.ts b/src/schema.ts
index 18b0e8b..1f3dda8 100644
--- a/src/schema.ts
+++ b/src/schema.ts
@@ -22,5 +22,23 @@ const metaContentSchema = z.object({
 
 type MetaContent = z.infer<typeof metaContentSchema>;
 
-export { jsonSchema, metaContentSchema };
+/** It's like `safeParse` except it returns `T` on success and `undefined` on fail. */
+function parseish<T>(schema: z.ZodType<T>, value: unknown): T | undefined {
+  const result = schema.safeParse(value);
+  return result.success ? result.data : undefined;
+}
+
+const parseRelay = (relay: string | URL) => parseish(relaySchema, relay);
+
+const relaySchema = z.custom<URL>((relay) => {
+  if (typeof relay !== 'string') return false;
+  try {
+    const { protocol } = new URL(relay);
+    return protocol === 'wss:' || protocol === 'ws:';
+  } catch (_e) {
+    return false;
+  }
+});
+
+export { jsonSchema, metaContentSchema, parseRelay, relaySchema };
 export type { MetaContent };