1 files changed, 73 insertions, 0 deletions
diff --git a/static/src/assets/api.js b/static/src/assets/api.js
new file mode 100644
index 0000000..bec2740
--- /dev/null
+++ b/static/src/assets/api.js
@@ -0,0 +1,73 @@
+
+const doFetch = async (req) => {
+  let res, jsonRes;
+  try {
+    res = await fetch(req);
+    jsonRes = await res.json();
+
+  } catch (e) {
+
+    if (e instanceof SyntaxError)
+      e = new Error(`status ${res.status}, empty (or invalid) response body`);
+
+    console.error(`api call ${req.method} ${req.url}: unexpected error:`, e);
+    throw e;
+  }
+
+  if (jsonRes.error) {
+    console.error(
+      `api call ${req.method} ${req.url}: application error:`,
+      res.status,
+      jsonRes.error,
+    );
+
+    throw jsonRes.error;
+  }
+
+  return jsonRes;
+}
+
+// may throw
+const solvePow = async () => {
+
+  const res = await call('GET', '/api/pow/challenge');
+
+  const worker = new Worker('/assets/solvePow.js');
+
+  const p = new Promise((resolve, reject) => {
+    worker.postMessage({seedHex: res.seed, target: res.target});
+    worker.onmessage = resolve;
+  });
+
+  const powSol = (await p).data;
+  worker.terminate();
+
+  return {seed: res.seed, solution: powSol};
+}
+
+const call = async (method, route, opts = {}) => {
+  const { body = {}, requiresPow = false } = opts;
+
+  const reqOpts = { method };
+
+  if (requiresPow) {
+    const {seed, solution} = await solvePow();
+    body.powSeed = seed;
+    body.powSolution = solution;
+  }
+
+  if (Object.keys(body).length > 0) {
+
+    const form = new FormData();
+    for (const key in body) form.append(key, body[key]);
+
+    reqOpts.body = form;
+  }
+
+  const req = new Request(route, reqOpts);
+  return doFetch(req);
+}
+
+export {
+  call,
+}