feat: implement file upload feature

frontend/src/core/uploads/api.ts

@@ -0,0 +1,97 @@
+/**
+ * API functions for file uploads
+ */
+
+import { getBackendBaseURL } from "../config";
+
+export interface UploadedFileInfo {
+  filename: string;
+  size: number;
+  path: string;
+  virtual_path: string;
+  artifact_url: string;
+  extension?: string;
+  modified?: number;
+  markdown_file?: string;
+  markdown_path?: string;
+  markdown_virtual_path?: string;
+  markdown_artifact_url?: string;
+}
+
+export interface UploadResponse {
+  success: boolean;
+  files: UploadedFileInfo[];
+  message: string;
+}
+
+export interface ListFilesResponse {
+  files: UploadedFileInfo[];
+  count: number;
+}
+
+/**
+ * Upload files to a thread
+ */
+export async function uploadFiles(
+  threadId: string,
+  files: File[],
+): Promise<UploadResponse> {
+  const formData = new FormData();
+
+  files.forEach((file) => {
+    formData.append("files", file);
+  });
+
+  const response = await fetch(
+    `${getBackendBaseURL()}/api/threads/${threadId}/uploads`,
+    {
+      method: "POST",
+      body: formData,
+    },
+  );
+
+  if (!response.ok) {
+    const error = await response.json().catch(() => ({ detail: "Upload failed" }));
+    throw new Error(error.detail || "Upload failed");
+  }
+
+  return response.json();
+}
+
+/**
+ * List all uploaded files for a thread
+ */
+export async function listUploadedFiles(
+  threadId: string,
+): Promise<ListFilesResponse> {
+  const response = await fetch(
+    `${getBackendBaseURL()}/api/threads/${threadId}/uploads/list`,
+  );
+
+  if (!response.ok) {
+    throw new Error("Failed to list uploaded files");
+  }
+
+  return response.json();
+}
+
+/**
+ * Delete an uploaded file
+ */
+export async function deleteUploadedFile(
+  threadId: string,
+  filename: string,
+): Promise<{ success: boolean; message: string }> {
+  const response = await fetch(
+    `${getBackendBaseURL()}/api/threads/${threadId}/uploads/${filename}`,
+    {
+      method: "DELETE",
+    },
+  );
+
+  if (!response.ok) {
+    throw new Error("Failed to delete file");
+  }
+
+  return response.json();
+}

frontend/src/core/uploads/hooks.ts

@@ -0,0 +1,79 @@
+/**
+ * React hooks for file uploads
+ */
+
+import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import { useCallback } from "react";
+
+import {
+  deleteUploadedFile,
+  listUploadedFiles,
+  uploadFiles,
+  type UploadedFileInfo,
+  type UploadResponse,
+} from "./api";
+
+/**
+ * Hook to upload files
+ */
+export function useUploadFiles(threadId: string) {
+  const queryClient = useQueryClient();
+
+  return useMutation<UploadResponse, Error, File[]>({
+    mutationFn: (files: File[]) => uploadFiles(threadId, files),
+    onSuccess: () => {
+      // Invalidate the uploaded files list
+      void queryClient.invalidateQueries({
+        queryKey: ["uploads", "list", threadId],
+      });
+    },
+  });
+}
+
+/**
+ * Hook to list uploaded files
+ */
+export function useUploadedFiles(threadId: string) {
+  return useQuery({
+    queryKey: ["uploads", "list", threadId],
+    queryFn: () => listUploadedFiles(threadId),
+    enabled: !!threadId,
+  });
+}
+
+/**
+ * Hook to delete an uploaded file
+ */
+export function useDeleteUploadedFile(threadId: string) {
+  const queryClient = useQueryClient();
+
+  return useMutation({
+    mutationFn: (filename: string) => deleteUploadedFile(threadId, filename),
+    onSuccess: () => {
+      // Invalidate the uploaded files list
+      void queryClient.invalidateQueries({
+        queryKey: ["uploads", "list", threadId],
+      });
+    },
+  });
+}
+
+/**
+ * Hook to handle file uploads in submit flow
+ * Returns a function that uploads files and returns their info
+ */
+export function useUploadFilesOnSubmit(threadId: string) {
+  const uploadMutation = useUploadFiles(threadId);
+
+  return useCallback(
+    async (files: File[]): Promise<UploadedFileInfo[]> => {
+      if (files.length === 0) {
+        return [];
+      }
+
+      const result = await uploadMutation.mutateAsync(files);
+      return result.files;
+    },
+    [uploadMutation],
+  );
+}

frontend/src/core/uploads/index.ts

@@ -0,0 +1,6 @@
+/**
+ * File uploads module
+ */
+
+export * from "./api";
+export * from "./hooks";