feat: add listing logger channels in a guild

This commit also allows in the database to hold more than one channel
per guild and introduces clippy linting.

Closes #2

BREAKING CHANGES: The database schema changed from its root. All
databases should be dropped and recreated before running this new
version.

migrations/20231122220824_guild_log_channels.sql

@@ -7,7 +7,8 @@
 -- them from the database. This operation is noop in Rust and should
 -- therefore not cost a single CPU cycle.
 CREATE TABLE IF NOT EXISTS guild_log_channels (
-       guild_id INTEGER PRIMARY KEY,
+       guild_id INTEGER NOT NULL,
        channel_id INTEGER NOT NULL,
        UNIQUE(guild_id, channel_id)
 );
+CREATE INDEX IF NOT EXISTS guild_log_channels_guild_id ON guild_log_channels(guild_id);

src/db/mod.rs

@@ -1,7 +1,10 @@
+#![allow(clippy::cast_possible_wrap, clippy::cast_sign_loss)]
+
 use std::env;
 
 use poise::serenity_prelude::{ChannelId, GuildId};
 use sqlx::SqlitePool;
+use tracing::error;
 
 pub type Result<T> = ::std::result::Result<T, sqlx::Error>;
 
@@ -22,9 +25,9 @@ impl Database {
 
     pub async fn get_logging_channel(
         &self,
-        guild_id: u64,
+        guild_id: GuildId,
     ) -> Result<Vec<u64>> {
-        let guild_id = guild_id as i64;
+        let guild_id = guild_id.0 as i64;
         let channels = sqlx::query!(
             r#"
 SELECT channel_id
@@ -34,7 +37,11 @@ WHERE guild_id = ?1
             guild_id
         )
         .fetch_all(&self.pool)
-        .await?;
+        .await
+        .map_err(|e| {
+            error!("Error getting logging channels for guild {guild_id}: {e:?}");
+            e
+        })?;
         Ok(channels.iter().map(|id| id.channel_id as u64).collect())
     }
 
@@ -57,6 +64,10 @@ VALUES ( ?1, ?2 )
         )
         .execute(&mut *conn)
         .await
+        .map_err(|e| {
+            error!("Error setting channel {channel_id} as logger for guild {guild_id}: {e:?}");
+            e
+        })
         .map(|_| ())
     }
 }

src/discord/commands.rs

@@ -2,12 +2,13 @@ use super::{Context, Error};
 
 use super::utils::serenity;
 
+#[allow(clippy::unused_async)]
 #[poise::command(
     slash_command,
-    subcommands("add_channel"),
+    subcommands("add_channel", "list_channels"),
     required_permissions = "ADMINISTRATOR"
 )]
-pub async fn logging(_ctx: Context<'_>, _arg: String) -> Result<(), Error> {
+pub async fn logging(_ctx: Context<'_>) -> Result<(), Error> {
     Ok(())
 }
 
@@ -18,7 +19,7 @@ pub async fn add_channel(
 ) -> Result<(), Error> {
     let channel_id = channel.id();
     let response = match ctx.guild_id() {
-        None => "Error: Could not determine the guild's ID.".to_owned(),
+        None => "Error: Could not determine the guild's ID".to_owned(),
         Some(guild_id) => {
             match ctx
                 .data()
@@ -26,7 +27,7 @@ pub async fn add_channel(
                 .set_logging_channel(guild_id, channel_id)
                 .await
             {
-                Ok(_) => format!(
+                Ok(()) => format!(
                     "Added channel <#{channel_id}> as a logging channel"
                 ),
                 Err(e) => {
@@ -34,7 +35,7 @@ pub async fn add_channel(
                         if db_error.is_unique_violation() {
                             format!("Channel <#{channel_id}> is already a logging channel")
                         } else {
-                            format!("Error: {:?}", e)
+                            format!("Error: {e:?}")
                         }
                     } else {
                         format!(
@@ -48,3 +49,31 @@ pub async fn add_channel(
     ctx.say(response).await?;
     Ok(())
 }
+
+#[poise::command(slash_command, aliases("list-channels"))]
+pub async fn list_channels(ctx: Context<'_>) -> Result<(), Error> {
+    let response = match ctx.guild_id() {
+        None => "Error: Could not determine the guild's ID".to_owned(),
+        Some(guild_id) => {
+            match ctx.data().database.get_logging_channel(guild_id).await {
+                Ok(channels) => {
+                    if channels.is_empty() {
+                        "No channels registered as loggers".to_owned()
+                    } else {
+                        format!(
+                            "Here are the channels currently set as loggers:\n{}",
+                            channels
+                                .iter()
+                                .map(|channel| format!("- <#{channel}>"))
+                                .collect::<Vec<String>>()
+                                .join("\n")
+                        )
+                    }
+                }
+                Err(e) => format!("Could not retrieve loggers: {e:?}"),
+            }
+        }
+    };
+    ctx.say(response).await?;
+    Ok(())
+}

src/discord/mod.rs

@@ -8,9 +8,8 @@ use utils::serenity;
 use commands::logging;
 use utils::{BotData, Context, Error};
 
-pub async fn make_bot() -> color_eyre::Result<FrameworkBuilder<BotData, Error>>
-{
-    let framework = poise::Framework::builder()
+pub fn make_bot() -> FrameworkBuilder<BotData, Error> {
+    poise::Framework::builder()
         .options(poise::FrameworkOptions {
             commands: vec![logging()],
             ..Default::default()
@@ -26,6 +25,5 @@ pub async fn make_bot() -> color_eyre::Result<FrameworkBuilder<BotData, Error>>
                 .await?;
                 Ok(BotData::new().await?)
             })
-        });
-    Ok(framework)
+        })
 }

src/main.rs

@@ -1,3 +1,5 @@
+#![warn(clippy::style, clippy::pedantic)]
+
 mod utils;
 mod db;
 mod discord;
@@ -10,7 +12,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
     color_eyre::install()?;
     utils::setup_logging();
 
-    let bot = discord::make_bot().await?;
+    let bot = discord::make_bot();
     bot.run().await?;
 
     Ok(())