Add create account functionality

server/api/account.post.ts

@@ -0,0 +1,53 @@
+import { readAccounts, writeAccounts, nextAccountId } from "~/server/database";
+import { Account } from "~/shared/types/account";
+
+export default defineEventHandler(async (event) => {
+	let session = await getAccountSession(event);
+	if (session) {
+		throw createError({
+			status: 409,
+			message: "Cannot create account while having an active session."
+		});
+	}
+
+	const formData = await readFormData(event);
+	const name = formData.get("name");
+
+	const accounts = await readAccounts();
+	let account: Account;
+	if (typeof name === "string") {
+		if (name === "") {
+			throw createError({
+				status: 400,
+				message: "Name cannot be blank",
+			});
+		}
+		if (accounts.some(account => account.name && account.name.toLowerCase() === name.toLowerCase())) {
+			throw createError({
+				status: 409,
+				message: "User already exists",
+			});
+		}
+
+		account = {
+			id: await nextAccountId(),
+			type: "regular",
+			name,
+		};
+
+	} else if (name === null) {
+		account = {
+			id: await nextAccountId(),
+			type: "anonymous",
+		};
+	} else {
+		throw createError({
+			status: 400,
+			message: "Invalid name",
+		});
+	}
+
+	accounts.push(account);
+	await writeAccounts(accounts);
+	await setAccountSession(event, account.id);
+})