Improve mime type handling using magic byes

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

src/screens/editors/editMeme.tsx

@@ -17,7 +17,8 @@ import {
   allowedMimeTypes,
   deleteMeme,
   favoriteMeme,
-  getMemeType,
+  getMemeTypeFromMimeType,
+  guessMimeType,
   noOp,
   validateMemeTitle,
 } from '../../utilities';
@@ -47,6 +48,7 @@ const EditMeme = ({
   const [hasChanges, setHasChanges] = useState(false);
 
   const [memeError, setMemeError] = useState<Error>();
+
   const [memeTitle, setMemeTitle] = useState(validateMemeTitle(meme.title));
   const [memeTags, setMemeTags] = useState(
     new Map<string, Tag>(meme.tags.map(tag => [tag.id.toHexString(), tag])),
@@ -104,10 +106,16 @@ const EditMeme = ({
     const file = await pickSingle({ type: allowedMimeTypes }).catch(noOp);
     if (!file) return;
 
-    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-    const mimeType = file.type!;
-    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-    const memeType = getMemeType(mimeType)!;
+    const mimeType = await guessMimeType(file.uri, file.type);
+    if (!mimeType) {
+      setMemeError(
+        new Error('Could not determine MIME type or file is not supported.'),
+      );
+      return;
+    }
+
+    const memeType = getMemeTypeFromMimeType(mimeType);
+    if (!memeType) return;
 
     const fileExtension = extension(mimeType) as string;
     if (!fileExtension) return;
@@ -122,7 +130,7 @@ const EditMeme = ({
 
     realm.write(() => {
       meme.filename = filename;
-      meme.type = memeType;
+      meme.memeType = memeType;
       meme.mimeType = mimeType;
       meme.size = size;
     });