Implement blackball election algorithm for discord

rs/cmd/discord_blackball_bot/main.rs

@@ -1,18 +1,78 @@
 use std::env;
 
+use serenity::all::{GuildId, UserId};
 use serenity::async_trait;
 use serenity::model::channel::Message;
 use serenity::prelude::*;
 
 struct Handler;
 
+#[derive(Debug)]
+enum BotError {
+    MissingInviteTarget,
+    MissingGuildId,
+}
+
+
+impl Handler {
+    async fn attempt_election(&self, ctx: Context, who: UserId) -> Result<()> {
+
+    }
+
+    async fn handle_message(&self, ctx: Context, msg: Message) -> Result<()> {
+        if !msg.content.starts_with("!invite") {
+            return;
+        }
+
+        match msg.content.split(" ").nth(1) {
+            None => Err(BotError::MissingInviteTarget),
+            Some(v) => serenity
+        }
+    }
+
+    async fn n_members(&self, ctx: Context, guild: GuildId) -> Result<u64> {
+        guild.members(
+            &ctx.http,
+            None,
+            None,
+        ).await?.into_iter().count()
+    }
+
+    async fn n_sponsors(&self, ctx: Context, n_members: u64) -> Result<u64> {
+        match n_members {
+            n if n < 5 => 1,
+            _ => 2
+        }
+    }
+
+    /// Calculate the number of votes needed to elect a new member.
+    async fn quorum(&self, ctx: Context, n_members: u64) -> Result<u64> {
+        // at least 12 members are needed if there are more than
+        // 12 members in the club, otherwise all members must vote.
+        match n_members {
+            n if n < 12 => n,
+            _ => 12
+        }
+    }
+
+    /// how many black balls at minimum are required to reject an election.
+    async fn n_balls_exclude(&self, ctx: Context, ballot_size: u64) -> Result<u64> {
+        if ballot_size > 18 {
+            2
+        }
+
+        1
+    }
+}
+
 #[async_trait]
 impl EventHandler for Handler {
     async fn message(&self, ctx: Context, msg: Message) {
-        if msg.content == "!ping" {
-            if let Err(why) = msg.channel_id.say(&ctx.http, "Pong!").await {
-                println!("Error sending message: {why:?}");
-            }
+        match self.handle_message(ctx, msg) {
+            Ok => (),
+            Err(e) => msg.channel_id.say(&ctx.http, e).await {
+                println!("Error sending message: {why?:}")
+            },
         }
     }
 }