move tag logic to upload.ts

src/utils/image-metadata.ts

@@ -6,7 +6,7 @@ import { Stickynotes } from '@soapbox/stickynotes';
 
 const console = new Stickynotes('ditto:uploaders');
 
-function toByteArray(f: File): Promise<Uint8Array> {
+export function toByteArray(f: File): Promise<Uint8Array> {
   return new Promise((resolve, reject) => {
     const reader = new FileReader();
     reader.addEventListener('loadend', (m) => {

src/utils/upload.ts

@@ -3,6 +3,9 @@ import { HTTPException } from '@hono/hono/http-exception';
 import { AppContext } from '@/app.ts';
 import { Conf } from '@/config.ts';
 import { DittoUpload, dittoUploads } from '@/DittoUploads.ts';
+import { getOptionalNip94Metadata, toByteArray } from '@/utils/image-metadata.ts';
+import type { Nip94MetadataOptional } from '@/interfaces/Nip94Metadata.ts';
+import { encodeHex } from '@std/encoding/hex';
 
 interface FileMeta {
   pubkey: string;
@@ -30,12 +33,31 @@ export async function uploadFile(
   }
 
   const tags = await uploader.upload(file, { signal });
+  const tagMap = tags.reduce((map, value) => map.set(value[0], value.slice(1)), new Map<string, string[]>());
+
   const url = tags[0][1];
 
   if (description) {
     tags.push(['alt', description]);
   }
 
+  let metadata: Nip94MetadataOptional | undefined;
+  if (!tagMap.has('dim')) {
+    // blurhash needs us to call sharp() anyway to decode the image data.
+    // all getOptionalNip94Metadata does is call these in sequence, plus
+    // one extra sha256 which is whatever (and actually does come in handy later.)
+    metadata ??= await getOptionalNip94Metadata(file);
+    tags.push(['dim', metadata.dim!]);
+    if (!tagMap.has('blurhash')) {
+      tags.push(['blurhash', metadata.blurhash!]);
+    }
+  }
+  if (!tagMap.has('x') || !tagMap.has('ox')) {
+    const hash = metadata?.x || await crypto.subtle.digest('SHA-256', await toByteArray(file)).then(encodeHex);
+    tags.push(['x', hash!]);
+    tags.push(['ox', hash!]);
+  }
+
   const upload = {
     id: crypto.randomUUID(),
     url,