1 files changed, 43 insertions, 0 deletions
diff --git a/fig-frontend/client/src/twitch.ts b/fig-frontend/client/src/twitch.ts
new file mode 100644
index 0000000..4c264be
--- /dev/null
+++ b/fig-frontend/client/src/twitch.ts
@@ -0,0 +1,43 @@
+import * as Config from "./config";
+
+function generateNonce(): string {
+  var arr = new Uint8Array(20);
+  window.crypto.getRandomValues(arr);
+  return Array.from(arr, b => b.toString(16).padStart(2, "0")).join("");
+}
+
+export function startTwitchAuth() {
+  const nonce = generateNonce();
+  document.cookie = `authnonce=${nonce}; path=/;`;
+  window.location.href =
+    `https://id.twitch.tv/oauth2/authorize?response_type=id_token`
+      + `&client_id=${Config.CLIENT_ID}`
+      + `&redirect_uri=${Config.URL}`
+      + `&scope=openid`
+      + `&nonce=${nonce}`
+      + `&claims=${{id_token: {preferred_username: null}}}`
+    ;
+}
+
+export function getFragmentQuery(): Map<string, string> {
+  let query = new Map();
+  const hashQuery = document.location.hash.slice(1).split("&");
+  for (let equals of hashQuery) {
+    const pair = equals.split("=");
+    query.set(decodeURIComponent(pair[0]), decodeURIComponent(pair[1]));
+  }
+  return query;
+}
+
+export function getAuthToken(): String | null {
+  const frag = getFragmentQuery();
+  const token = frag.get("id_token");
+  if (token) {
+    document.cookie = `id_token=${token}; path=/; SameSite=Strict`;
+  }
+  for (let c of document.cookie.split("; ")) {
+    const [k, v] = c.split("=");
+    if (k === "id_token") return v;
+  }
+  return null;
+}