initial commit

main.ts

@@ -0,0 +1,180 @@
+import {
+  Client,
+  Events,
+  GatewayIntentBits,
+  GuildBasedChannel,
+  Message,
+} from "discord.js";
+import { DB } from "sqlite";
+
+import config from "./config.json" with { type: "json" };
+
+const db = new DB("db.sqlite");
+db.execute(`
+  CREATE TABLE IF NOT EXISTS bag(
+    userid INTEGER NOT NULL PRIMARY KEY,
+    idx INTEGER
+  );
+  CREATE TABLE IF NOT EXISTS time(
+    id INTEGER NOT NULL PRIMARY KEY,
+    time INTEGER NOT NULL
+  )
+`);
+
+const client = new Client({
+  intents: [
+    GatewayIntentBits.Guilds,
+    // allow enumeration of all members with the opt-in role
+    GatewayIntentBits.GuildMembers,
+    GatewayIntentBits.GuildPresences,
+  ],
+});
+
+client.once(Events.ClientReady, (readyClient) => {
+  console.log(`Ready! Logged in as ${readyClient.user.tag}`);
+  const [timestamp] = db.query("SELECT time FROM time");
+  if (!timestamp) {
+    const date = getNextDate();
+    console.log(`Scheduled next blogger for ${date}`);
+    setTimeout(nextBloggerAndRepeat, date.getTime() - Date.now());
+  } else {
+    const date = new Date((timestamp[0] as number) * 1000);
+    console.log(`Scheduled next blogger for ${date}`);
+    setTimeout(nextBloggerAndRepeat, date.getTime() - Date.now());
+  }
+});
+
+client.login(config.token);
+
+function getNextDate(): Date {
+  const date = new Date();
+  // date.setUTCSeconds(date.getUTCSeconds() + 10);
+  date.setUTCSeconds(0);
+  date.setUTCMinutes(0);
+  date.setUTCHours(date.getUTCHours() + 1);
+  // date.setUTCHours(0);
+  // date.setUTCDate(date.getUTCDate() + 1);
+  return date;
+}
+
+async function nextBloggerAndRepeat() {
+  await nextBlogger();
+  const date = getNextDate();
+  setTimeout(nextBloggerAndRepeat, date.getTime() - Date.now());
+  console.log(`Scheduled next blogger for ${date}`);
+  db.query(
+    "INSERT INTO time(id,time) VALUES(0,?) ON CONFLICT(id) DO UPDATE SET time = ?",
+    [
+      Math.floor(date.getTime() / 1000),
+      Math.floor(date.getTime() / 1000),
+    ],
+  );
+}
+
+// this uses a bag randomizer algorithm to keep things fair.
+
+// it uses sqlite to provide robustness against crashes and bot restarts.
+// it associates a userid with an idx, which is either an integer or null.
+// when it's time to select the next blogger,
+// it selects all users with non-null idxs, and sorts by idx,
+// then it pops the top one off that array, and marks that idx as null.
+
+// this system allows it to handle someone opting in or out between bag shuffles.
+// see below comments for the reasoning behind this.
+async function nextBlogger() {
+  const guild = await client.guilds.fetch(config.guildID);
+  await guild.members.fetch(); // refresh the cache
+  const optinRole = await guild.roles.fetch(config.optinRoleID);
+  const selectedRole = await guild.roles.fetch(config.selectedRoleID);
+  const blogChannel = await guild.channels.fetch(config.blogChannelID);
+
+  const bagOfUsers: Array<string> = [];
+  optinRole?.members.each((member) => bagOfUsers.push(member.id));
+
+  for (const user of bagOfUsers) {
+    const dbUser = db.query("SELECT userid FROM bag WHERE userid = ?", [user]);
+    // check if this user opted-in before bag was empty.
+    // if so we add them to the bag at a random idx.
+    if (dbUser.length == 0) {
+      const [[numUsersInDB]] = db.query<[number]>("SELECT COUNT(*) FROM bag");
+      const idx = Math.floor(Math.random() * numUsersInDB);
+      db.query(
+        "INSERT INTO bag(userid,idx) VALUES(?,?) ON CONFLICT(userid) DO UPDATE SET idx = ?",
+        [user, idx, idx],
+      );
+    }
+  }
+
+  // if bag is empty, refill and shuffle it
+  const [[numUsersInDB]] = db.query(
+    "SELECT COUNT(*) FROM bag WHERE idx = NULL",
+  );
+  if (numUsersInDB == 0) {
+    shuffleUserBag(bagOfUsers);
+
+    db.execute("DELETE FROM bag");
+    for (const idx in bagOfUsers) {
+      db.query("INSERT INTO bag(userid,idx) VALUES(?,?)", [
+        bagOfUsers[idx],
+        idx,
+      ]);
+    }
+  }
+
+  const dbBagOfUsers = db.query<[bigint]>(
+    "SELECT userid FROM bag WHERE idx IS NOT NULL ORDER BY idx ASC",
+  );
+
+  const selectedUserRow = dbBagOfUsers.pop();
+  console.log("selected user row " + selectedUserRow);
+  if (!selectedUserRow) return; // nobody has opted-in
+  const selectedUserID = (selectedUserRow[0] as bigint).toString();
+
+  // check if this user opted-out before bag was empty.
+  // if so we delete their db row and rerun this function.
+  // this prevents someone from accidentally getting picked after they opted-out.
+  if (!bagOfUsers.includes(selectedUserID)) {
+    db.query("DELETE FROM bag WHERE userid = ?", [selectedUserID]);
+    return nextBlogger();
+  }
+
+  db.query("UPDATE bag SET idx = NULL WHERE userid = ?", [selectedUserID]);
+  selectedRole?.members.each(async (member) => {
+    if (member.id != selectedUserID) {
+      await member.roles.remove(config.selectedRoleID);
+    }
+  });
+  const selectedUser = await guild.members.fetch(selectedUserID);
+  selectedUser.roles.add(config.selectedRoleID);
+  if (blogChannel) await sillyPing(blogChannel, selectedUserID);
+
+  console.log(db.query("SELECT userid,idx FROM bag"));
+}
+
+// a lazy way to do this.
+// i can use an array of template strings so long as whatever variable we use inside it is in scope.
+// this probably evaluates ALL the strings, even though we discard all but one.
+// but it's good enough.
+function sillyPing(
+  channel: GuildBasedChannel,
+  userID: string,
+): Promise<Message<true>> {
+  if (!channel.isTextBased()) throw new Error("Channel is not text-based");
+  const messages = [
+    `<@${userID}>, it's your turn!`,
+    `Go go go <@${userID}>!`,
+    `<@${userID}>: ready, set, RAMBLE!!`,
+    `Here's your 15 minutes of fame, <@${userID}>! No take-backsies!`,
+  ];
+  const message = messages[Math.floor(Math.random() * messages.length)];
+  return channel.send(message);
+}
+
+// in-place shuffle
+// https://stackoverflow.com/a/12646864
+function shuffleUserBag(array: Array<unknown>) {
+  for (let i = array.length - 1; i >= 0; i--) {
+    const j = Math.floor(Math.random() * (i + 1));
+    [array[i], array[j]] = [array[j], array[i]];
+  }
+}