Advanced file sharing

This is a WIP for advanced file sharing, but I won't pursue this for now since using symlinks in the file system works for me, and this is adding a ton of complexity I don't want or need right now.

routes/api/files/upload.tsx

@@ -1,7 +1,7 @@
 import { Handlers } from 'fresh/server.ts';
 
 import { DirectoryFile, FreshContextState } from '/lib/types.ts';
-import { createFile, getFiles } from '/lib/data/files.ts';
+import { createFile, getDirectoryAccess, getFileAccess, getFiles } from '/lib/data/files.ts';
 
 interface Data {}
 
@@ -29,9 +29,25 @@ export const handler: Handlers<Data, FreshContextState> = {
       return new Response('Bad Request', { status: 400 });
     }
 
-    // TODO: Verify user has write access to path and get the appropriate ownerUserId
+    let { hasWriteAccess, ownerUserId, ownerParentPath } = await getFileAccess(
+      context.state.user.id,
+      parentPath,
+      name.trim(),
+    );
 
-    const createdFile = await createFile(context.state.user.id, parentPath, name.trim(), await contents.arrayBuffer());
+    if (!hasWriteAccess) {
+      const directoryAccessResult = await getDirectoryAccess(context.state.user.id, parentPath);
+
+      hasWriteAccess = directoryAccessResult.hasWriteAccess;
+      ownerUserId = directoryAccessResult.ownerUserId;
+      ownerParentPath = directoryAccessResult.ownerParentPath;
+
+      if (!hasWriteAccess) {
+        return new Response('Forbidden', { status: 403 });
+      }
+    }
+
+    const createdFile = await createFile(ownerUserId, ownerParentPath, name.trim(), await contents.arrayBuffer());
 
     const newFiles = await getFiles(context.state.user.id, parentPath);