From 647c45a0e7fd233360e3ee503845aa8fbfe3ac9c Mon Sep 17 00:00:00 2001
From: Natsu Kagami <natsukagami@gmail.com>
Date: Mon, 9 Dec 2019 16:22:01 -0500
Subject: [PATCH] Choose

---
 youmubot/src/commands/community/mod.rs | 92 +++++++++++++++++++++++++-
 1 file changed, 90 insertions(+), 2 deletions(-)

diff --git a/youmubot/src/commands/community/mod.rs b/youmubot/src/commands/community/mod.rs
index 4ddad82..620e09b 100644
--- a/youmubot/src/commands/community/mod.rs
+++ b/youmubot/src/commands/community/mod.rs
@@ -1,4 +1,19 @@
-use serenity::framework::standard::macros::group;
+use rand::{
+    distributions::{Distribution, Uniform},
+    thread_rng,
+};
+use serenity::prelude::*;
+use serenity::{
+    framework::standard::{
+        macros::{command, group},
+        Args, CommandError as Error, CommandResult,
+    },
+    model::{
+        channel::{Channel, Message},
+        user::OnlineStatus,
+    },
+    utils::MessageBuilder,
+};
 
 mod votes;
 
@@ -7,7 +22,80 @@ use votes::VOTE_COMMAND;
 group!({
     name: "community",
     options: {
+        only_in: "guilds",
         description: "Community related commands. Usually comes with some sort of delays, since it involves pinging",
     },
-    commands: [vote],
+    commands: [choose, vote],
 });
+
+#[command]
+#[description = r"👑 Randomly choose an active member and mention them!
+Note that only online/idle users in the channel are chosen from."]
+#[usage = "[title = the chosen one]"]
+#[example = "the strongest in Gensokyo"]
+#[max_args(1)]
+pub fn choose(ctx: &mut Context, m: &Message, mut args: Args) -> CommandResult {
+    let title = if args.is_empty() {
+        "the chosen one".to_owned()
+    } else {
+        args.single::<String>()?
+    };
+
+    let users: Result<Vec<_>, Error> = {
+        let guild = m.guild(&ctx).unwrap();
+        let guild = guild.read();
+        let presences = &guild.presences;
+        let channel = m.channel_id.to_channel(&ctx)?;
+        if let Channel::Guild(channel) = channel {
+            let channel = channel.read();
+            Ok(channel
+                .members(&ctx)?
+                .into_iter()
+                .filter(|v| !v.user.read().bot)
+                .map(|v| v.user_id())
+                .filter(|v| {
+                    presences
+                        .get(v)
+                        .map(|presence| {
+                            presence.status == OnlineStatus::Online
+                                || presence.status == OnlineStatus::Idle
+                        })
+                        .unwrap_or(false)
+                })
+                .collect())
+        } else {
+            panic!()
+        }
+    };
+    let users = users?;
+
+    if users.len() < 2 {
+        m.reply(
+            &ctx,
+            "🍰 Have this cake for yourself because no-one is here for the gods to pick.",
+        )?;
+        return Ok(());
+    }
+
+    let winner = {
+        let uniform = Uniform::from(0..users.len());
+        let mut rng = thread_rng();
+        &users[uniform.sample(&mut rng)]
+    };
+
+    m.channel_id.send_message(&ctx, |c| {
+        c.content(
+            MessageBuilder::new()
+                .push("👑 The Gensokyo gods have gathered around and decided, out of ")
+                .push_bold(format!("{}", users.len()))
+                .push(" potential prayers, ")
+                .push(winner.mention())
+                .push(" will be ")
+                .push_bold_safe(title)
+                .push(". Congrats! 🎉 🎊 🥳")
+                .build(),
+        )
+    })?;
+
+    Ok(())
+}