Finish Discord activity implementation

1 files changed, 113 insertions, 0 deletions

diff --git a/priv/static/discordActivity.js b/priv/static/discordActivity.js
new file mode 100644
index 0000000..7ec4872
--- /dev/null
+++ b/priv/static/discordActivity.js
@@ -0,0 +1,113 @@
+import { DiscordSDK } from "/static/discord-embedded-app-sdk/Discord.js";
+
+const discordSdk = new DiscordSDK(DISCORD_CLIENT_ID);
+
+const updateInstanceRoomInfo = () => {
+  const contentEl = document.getElementById("instance-room-info-content");
+
+  const defaultContents = document.createElement("i");
+  defaultContents.innerText = "none yet";
+  if (!contentEl.hasChildNodes()) {
+    contentEl.replaceChildren(defaultContents);
+  }
+
+  fetch(
+    `/.proxy/discord_activity/rooms_for_instance?discord_activity_inner&instance_id=${discordSdk.instanceId}`,
+  )
+    .then((response) => {
+      if (!response.ok) {
+        throw new Error(`Fetching instance room info failed with status code ${response.status}`);
+      }
+      return response.json();
+    })
+    .then((json) => {
+      let docFragment = new DocumentFragment();
+      if (json.length === 0) {
+        docFragment.appendChild(defaultContents);
+      } else {
+        const listEl = docFragment.appendChild(document.createElement("ul"));
+        for (const roomInfo of json) {
+          const item = listEl.appendChild(document.createElement("li"));
+          item.innerText = roomInfo["host_username"] + " ";
+          const form = item.appendChild(document.createElement("form"));
+          form.action = roomUrl(roomInfo["room_id"]);
+          form.target = "activity-inner-iframe";
+          form.style.display = "inline";
+          const hiddenInput = form.appendChild(document.createElement("input"));
+          hiddenInput.type = "hidden";
+          hiddenInput.name = "discord_activity_inner";
+          const submitInput = form.appendChild(document.createElement("input"));
+          submitInput.type = "submit";
+          submitInput.value = "join";
+        }
+      }
+      contentEl.replaceChildren(docFragment);
+    })
+    .catch((error) => {
+      console.error(error);
+    });
+};
+
+updateInstanceRoomInfo();
+const INSTANCE_ROOM_INFO_INTERVAL = 3000;
+let instanceRoomInfoIntervalId = setInterval(updateInstanceRoomInfo, INSTANCE_ROOM_INFO_INTERVAL);
+
+const iframe = document.querySelector("iframe");
+// It doesn't matter if the iframe's initial loading finishes before this is added
+iframe.addEventListener("load", (_) => {
+  clearInterval(instanceRoomInfoIntervalId);
+
+  const locationURL = new URL(iframe.contentWindow.location);
+  const locationPath = locationURL.pathname + locationURL.search;
+  if (locationPath === HOME_URL) {
+    instanceRoomInfoIntervalId = setInterval(updateInstanceRoomInfo, INSTANCE_ROOM_INFO_INTERVAL);
+    iframe.className = "at-home";
+  } else {
+    iframe.className = "";
+  }
+});
+
+discordSdk
+  .ready()
+  .then(() => {
+    return discordSdk.commands.authorize({
+      client_id: DISCORD_CLIENT_ID,
+      response_type: "code",
+      state: "",
+      prompt: "none",
+      scope: ["identify"],
+    });
+  })
+  .then((result) => {
+    const { code } = result;
+
+    return fetch(ACCESS_TOKEN_URL, {
+      body: new URLSearchParams([["code", code]]),
+      headers: {
+        "content-type": "application/x-www-form-urlencoded",
+        "x-csrf-token": document.body.dataset.csrfToken,
+      },
+      method: "POST",
+    });
+  })
+  .then((response) => {
+    if (!response.ok) {
+      throw new Error(`Getting access token failed with status code ${response.status}`);
+    }
+    // Note: the access token should now be in the session cookie as well
+    return response.text();
+  })
+  .then((accessToken) => {
+    return discordSdk.commands.authenticate({ access_token: accessToken });
+  })
+  .then((authenticationResult) => {
+    if (authenticationResult === null) {
+      throw new Error("Authenticating with Discord client failed");
+    }
+    iframe.style.display = null;
+  })
+  .catch((error) => {
+    console.error(error);
+    const CLOSE_ABNORMAL = 1006;
+    discordSdk.close(CLOSE_ABNORMAL, "Could not obtain authorizations required to run this app.");
+  });