refactor: simplify code, better organize it, and comment it

src/discord/events/everyone.rs

@@ -0,0 +1,68 @@
+use crate::db::Database;
+
+use super::super::Result;
+
+use super::super::error::Error as DiscordError;
+
+use poise::serenity_prelude::{self as serenity, CreateEmbed};
+use tracing::{error, info};
+
+fn message_for_everyone_mention(
+    embed: &mut CreateEmbed,
+    message: &serenity::Message,
+    guild_id: u64,
+) {
+    let author = message.author.clone();
+    let message_channel = message.channel_id.0;
+    embed
+        .title("Someone mentioned everyone!")
+        .field("Author", author.clone(), true)
+        .field("When", message.timestamp.naive_local().to_string(), true)
+        .field("Channel", format!("<#{message_channel}>"), true)
+        .field(
+            "Link",
+            format!(
+                "https://discord.com/channels/{guild_id}/{message_channel}/{}",
+                message.id
+            ),
+            false,
+        );
+}
+
+/// Handle messages mentioning everyone.
+///
+/// # Errors
+///
+/// This function will return an error if a message fails to be sent,
+/// if retrieving the list of channels registered as loggers fails, or
+/// if there is not guild ID that can be retrieved from the message.
+pub async fn handle_everyone_mention(
+    ctx: &serenity::Context,
+    database: &Database,
+    message: &serenity::Message,
+) -> Result {
+    info!("Message mentioning everyone: {message:?}");
+    if !message.mention_everyone {
+        return Ok(());
+    }
+    if message.guild_id.is_none() {
+        error!("Message without a guild_id! {message:?}");
+        return Err(DiscordError::GuildIdNotFound.boxed());
+    }
+    let guild_id = message.guild_id.unwrap();
+    let channels: Vec<serenity::ChannelId> =
+        database.get_logging_channels(guild_id).await?;
+    for channel in &channels {
+        // Ignore result, it'll be in the bot's logger
+        let _ = channel
+            .send_message(&ctx, |m| {
+                m.embed(|e| {
+                    message_for_everyone_mention(e, message, guild_id.0);
+                    e
+                })
+            })
+            .await
+            .map_err(|e| error!("Failed to send message: {e:?}"));
+    }
+    Ok(())
+}

src/discord/events/mod.rs

@@ -0,0 +1,34 @@
+use super::{utils::BotData, Error, Result};
+
+use poise::{
+    serenity_prelude::{self as serenity},
+    Event,
+};
+use tracing::info;
+
+mod everyone;
+use everyone::handle_everyone_mention;
+
+/// Function handling events the bot can see.
+///
+/// # Errors
+///
+/// This function will return an error if one of the functions error
+/// themselves.
+pub async fn event_handler(
+    ctx: &serenity::Context,
+    event: &Event<'_>,
+    _framework: poise::FrameworkContext<'_, BotData, Error>,
+    data: &BotData,
+) -> Result {
+    match event {
+        Event::Ready { data_about_bot } => {
+            info!("Logged in as {}", data_about_bot.user.name);
+        }
+        Event::Message { new_message } => {
+            handle_everyone_mention(ctx, &data.database, new_message).await?;
+        }
+        _ => {}
+    }
+    Ok(())
+}