1 files changed, 59 insertions, 0 deletions
diff --git a/packages/demobank-ui/src/hooks/config.ts b/packages/demobank-ui/src/hooks/config.ts
new file mode 100644
index 000000000..a3bd294db
--- /dev/null
+++ b/packages/demobank-ui/src/hooks/config.ts
@@ -0,0 +1,59 @@
+import { LibtoolVersion } from "@gnu-taler/taler-util";
+import { ErrorType, HttpError, HttpResponseServerError, RequestError, useApiContext } from "@gnu-taler/web-util/browser";
+import { useEffect, useState } from "preact/hooks";
+import { getInitialBackendBaseURL } from "./backend.js";
+
+/**
+ * Protocol version spoken with the bank.
+ *
+ * Uses libtool's current:revision:age versioning.
+ */
+export const BANK_INTEGRATION_PROTOCOL_VERSION = "0:0:0";
+
+async function getConfigState(
+  request: ReturnType<typeof useApiContext>["request"],
+): Promise<SandboxBackend.Config> {
+  const url = getInitialBackendBaseURL();
+  const result = await request<SandboxBackend.Config>(url, `config`);
+  return result.data;
+}
+
+export type ConfigResult = undefined
+  | { type: "ok", result: Required<SandboxBackend.Config> }
+  | { type: "wrong", result: SandboxBackend.Config }
+  | { type: "error", result: HttpError<SandboxBackend.SandboxError> }
+
+export function useConfigState(): ConfigResult {
+  const [checked, setChecked] = useState<ConfigResult>()
+  const { request } = useApiContext();
+
+  useEffect(() => {
+    getConfigState(request)
+      .then((result) => {
+        const r = LibtoolVersion.compare(BANK_INTEGRATION_PROTOCOL_VERSION, result.version)
+        if (r?.compatible) {
+          const complete: Required<SandboxBackend.Config> = {
+            currency_fraction_digits: result.currency_fraction_digits ?? 2,
+            currency_fraction_limit: result.currency_fraction_limit ?? 2,
+            fiat_currency: "",
+            have_cashout: result.have_cashout ?? false,
+            name: result.name,
+            version: result.version,
+          }
+          setChecked({ type: "ok", result: complete });
+        } else {
+          setChecked({ type: "wrong", result })
+        }
+      })
+      .catch((error: unknown) => {
+        if (error instanceof RequestError) {
+          const result = error.cause
+          setChecked({ type: "error", result });
+        }
+      });
+  }, []);
+
+  return checked;
+}
+
+