rewrite bot in TypeScript and add locale switching

tests/xiaomi-crypto.test.ts

@@ -0,0 +1,18 @@
+import { describe, expect, test } from "bun:test";
+import { buildEncryptedParams, computeSignedNonce, decryptData, encryptData } from "../src/xiaomi/client.js";
+
+describe("Xiaomi crypto", () => {
+  test("round-trips encrypted payloads and request params", () => {
+    const ssecurity = Buffer.from("test-ssecurity-key").toString("base64");
+    const nonce = Buffer.from("123456789012").toString("base64");
+    const signed = computeSignedNonce(ssecurity, nonce);
+    expect(decryptData(signed, encryptData(signed, '{"中文":"тест"}'))).toBe('{"中文":"тест"}');
+    const params = buildEncryptedParams("POST", "/test", ssecurity, { test: "hello", num: 42 });
+    expect(JSON.parse(decryptData(computeSignedNonce(ssecurity, params._nonce ?? ""), params.data ?? ""))).toEqual({
+      test: "hello",
+      num: 42,
+    });
+    expect(params.signature).toBeString();
+    expect(params.rc4_hash__).toBeString();
+  });
+});