Added form file processing

src/api.ts

@@ -0,0 +1,50 @@
+import { IBook, optionalBookProps, requiredBookProps } from "./types/book";
+
+const API_URL = import.meta.env.SNOWPACK_PUBLIC_API_URL;
+
+export const validState = (file: File | undefined): file is File => {
+  if (!file) throw new Error("Book file is required. Please, attach one");
+
+  if (!file.name.match(/\.(fb2|epub)/))
+    throw new Error(
+      "Wrong file type. Only FB2 and Epub files are supported. \
+      If you are trying to upload fb2.zip, please, uncopress it first."
+    );
+
+  if (file.size > 100 * 1024 * 1024)
+    throw new Error(
+      "File size is too big. Sorry, but parser is served on a rather cheap hosting, \
+      so application can't handle such big files."
+    );
+
+  return true;
+};
+
+export const submitFile = async (
+  file: File
+): Promise<{ [key: string]: string }> => {
+  const body = new FormData();
+  body.append("file", file);
+
+  try {
+    const res = await fetch(API_URL + "/uploadfile/", {
+      method: "POST",
+      body,
+    });
+
+    return await res.json();
+  } catch (err) {
+    console.log("Network error:", err.message);
+    throw err;
+  }
+};
+
+export const validateResponse = (
+  content: Record<string, unknown>
+): content is IBook => {
+  for (const key of requiredBookProps)
+    if (!(key in content))
+      throw new Error(`${key} is not specified in server response`);
+
+  return true;
+};

src/types/book.ts

@@ -1,7 +1,10 @@
-export interface IBook {
-  title: string;
-  author: string;
-  cover?: string;
-  content: string;
-  hash?: string;
-}
+export const requiredBookProps = ["title", "author", "content"] as const;
+export const optionalBookProps = ["cover", "hash"] as const;
+
+export type IBook =
+  | {
+      [key in typeof requiredBookProps[number]]: string;
+    }
+  | {
+      [key in typeof optionalBookProps[number]]: string | undefined;
+    };