Add share intent

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

src/utilities/filesystem.ts

@@ -25,9 +25,32 @@ const getMemeType = (mimeType: string): MEME_TYPE | undefined => {
   }
 };
 
+const guessMimeType = (filename: string): string | undefined => {
+  const extension = filename.split('.').pop()?.toLowerCase();
+  switch (extension) {
+    case 'bmp': {
+      return 'image/bmp';
+    }
+    case 'jpg':
+    case 'jpeg': {
+      return 'image/jpeg';
+    }
+    case 'png': {
+      return 'image/png';
+    }
+    case 'webp': {
+      return 'image/webp';
+    }
+    case 'gif': {
+      return 'image/gif';
+    }
+  }
+};
+
 export {
   allowedImageMimeTypes,
   allowedGifMimeTypes,
   allowedMimeTypes,
   getMemeType,
+  guessMimeType,
 };