feat: improve transparency of the join command

src/command/join.rs

@@ -1,12 +1,23 @@
 use std::sync::LazyLock;
 
-use twilight_model::application::{
+use snafu::{OptionExt, Snafu};
+use twilight_model::{
+    application::{
         command::{Command, CommandType},
-    interaction::{Interaction, application_command::CommandData},
+        interaction::Interaction,
+    },
+    channel::message::{Embed, MessageFlags},
+    http::interaction::{InteractionResponse, InteractionResponseType},
+    id::{
+        Id,
+        marker::{ChannelMarker, GuildMarker},
+    },
+};
+use twilight_util::builder::{
+    InteractionResponseDataBuilder, command::CommandBuilder, embed::EmbedBuilder,
 };
-use twilight_util::builder::command::CommandBuilder;
 
-use crate::command::State;
+use crate::{VCs, command::State};
 
 const NAME: &str = "join";
 const DESCRIPTION: &str = "The bot will join the same VC as you (with intention to record)";
@@ -18,23 +29,102 @@ pub static COMMAND: LazyLock<Command> = LazyLock::new(|| {
         .build()
 });
 
+#[derive(Debug, Snafu)]
+enum GetGuildAndChannelIdError {
+    /// this command was not used inside a guild (Discord server)
+    NotInGuild,
+
+    /// there is no user who invoked this command
+    NoUser,
+
+    /// there are no voice chats in this guild
+    NoVCsInGuild,
+
+    /// the user is not in a voice chat in this guild
+    UserNotInVC,
+}
+
+impl From<GetGuildAndChannelIdError> for Embed {
+    fn from(error: GetGuildAndChannelIdError) -> Embed {
+        match error {
+            GetGuildAndChannelIdError::NotInGuild => {
+                EmbedBuilder::new().title("Use this in a server").description("This bot can't find a VC to join if the command is used outside of a server (you might've used it in a DM?).").validate().unwrap().build()
+            }
+            GetGuildAndChannelIdError::NoUser => EmbedBuilder::new().title("Not invoked by a user").description("This command works by joining the same VC as the user, but this bot didn't receive any user data. So did no user invoke it?! (This error should be impossible!)").validate().unwrap().build(),
+            GetGuildAndChannelIdError::NoVCsInGuild => {
+                EmbedBuilder::new().title("No VCs in this server").description("This bot can't find a VC to join because there aren't any in this server right now.").validate().unwrap().build()
+            },
+            GetGuildAndChannelIdError::UserNotInVC => {
+
+                EmbedBuilder::new().title("You're not in a VC").description("This bot can't follow you into VC if you aren't in one in this server.").validate().unwrap().build()
+            },
+        }
+    }
+}
+
+#[tracing::instrument]
+fn get_guild_and_channel_id(
+    interaction: &Interaction,
+    vcs: &VCs,
+) -> Result<(Id<GuildMarker>, Id<ChannelMarker>), GetGuildAndChannelIdError> {
+    let guild_id = interaction.guild_id.context(NotInGuildSnafu)?;
+
+    let user_id = interaction
+        .member
+        .as_ref()
+        .and_then(|member| member.user.as_ref().map(|user| user.id))
+        .context(NoUserSnafu)?;
+
+    let guild_vcs = vcs.get(&guild_id).context(NoVCsInGuildSnafu)?;
+
+    let &channel_id = guild_vcs.get_left_for(&user_id).context(UserNotInVCSnafu)?;
+
+    Ok((guild_id, channel_id))
+}
+
 #[tracing::instrument]
 pub async fn handle(state: State, interaction: Interaction) {
     let vcs = state.vcs;
 
-    let guild_id = interaction.guild_id.expect("TODO");
-    // let user_id = data.user.map(|user| user.id).expect("TODO");
-
-    let user_id = interaction
-        .member
-        .and_then(|member| member.user.map(|user| user.id))
+    let (guild_id, channel_id) = match get_guild_and_channel_id(&interaction, &vcs) {
+        Ok((guild_id, channel_id)) => (guild_id, channel_id),
+        Err(error) => {
+            state
+                .discord_client
+                .interaction(state.discord_application_id)
+                .create_response(
+                    interaction.id,
+                    &interaction.token,
+                    &InteractionResponse {
+                        kind: InteractionResponseType::ChannelMessageWithSource,
+                        data: Some(
+                            InteractionResponseDataBuilder::new()
+                                .embeds([error.into()])
+                                .flags(MessageFlags::EPHEMERAL)
+                                .build(),
+                        ),
+                    },
+                )
+                .await
                 .expect("TODO");
 
-    let guild_vcs = vcs.get(&guild_id).expect("TODO");
-    tracing::error!(?guild_vcs, "TODO");
+            return;
+        }
+    };
 
-    let (&channel_id, user_in_vc_data) = guild_vcs.get_left_and_data_for(&user_id).expect("TODO");
-    tracing::error!(?user_in_vc_data, "TODO");
+    state
+        .discord_client
+        .interaction(state.discord_application_id)
+        .create_response(
+            interaction.id,
+            &interaction.token,
+            &InteractionResponse {
+                kind: InteractionResponseType::DeferredChannelMessageWithSource,
+                data: None,
+            },
+        )
+        .await
+        .expect("TODO");
 
     let call = tokio::spawn({
         let songbird = state.songbird.clone();
@@ -44,5 +134,20 @@ pub async fn handle(state: State, interaction: Interaction) {
     .unwrap()
     .expect("TODO");
 
+    let channel_mention = format!("<#{channel_id}>");
+
+    state
+        .discord_client
+        .interaction(state.discord_application_id)
+        .update_response(
+            &interaction.token,
+        ).embeds(Some(&[
+            EmbedBuilder::new().title("Joined VC with intent to record").description(&format!("This bot joined {channel_mention} and intends to start recording after a responsible disclosure and consent.")).validate().unwrap().build()
+        ]))
+        .await
+        .expect("TODO");
+
     tracing::error!(?call, "TODO");
+
+    let call_guard = call.lock().await;
 }

src/command/mod.rs

@@ -3,7 +3,10 @@ use std::{fmt::Debug, sync::Arc};
 use futures::future::BoxFuture;
 use patricia_tree::StringPatriciaMap;
 use songbird::Songbird;
-use twilight_model::application::{command::Command, interaction::Interaction};
+use twilight_model::{
+    application::{command::Command, interaction::Interaction},
+    id::{Id, marker::ApplicationMarker},
+};
 
 use crate::VCs;
 
@@ -13,8 +16,10 @@ mod opt_out;
 
 #[derive(Debug, Clone)]
 pub struct State {
-    pub vcs: Arc<VCs>,
+    pub discord_client: Arc<twilight_http::Client>,
+    pub discord_application_id: Id<ApplicationMarker>,
     pub songbird: Arc<Songbird>,
+    pub vcs: Arc<VCs>,
 }
 
 type Return = ();

src/main.rs

@@ -132,7 +132,7 @@ async fn main() -> Result<(), MainError> {
         .await
         .expect("couldn't get current Discord application"); // TODO
 
-    let application_id = current_application.id;
+    let discord_application_id = current_application.id;
 
     let shard_id = ShardId::new(0, 1);
     let intents = Intents::GUILD_VOICE_STATES;
@@ -150,7 +150,7 @@ async fn main() -> Result<(), MainError> {
     let event_types = EventTypeFlags::GUILD_VOICE_STATES | EventTypeFlags::INTERACTION_CREATE;
     let mut next_event = shard.next_event(event_types);
 
-    let interaction_client = discord_client.interaction(application_id);
+    let interaction_client = discord_client.interaction(discord_application_id);
 
     let commands = all_commands();
 
@@ -172,11 +172,17 @@ async fn main() -> Result<(), MainError> {
     let command_router = CommandRouter::from_iter(commands);
 
     let vcs = initialize_vcs(&discord_client).await;
+
+    let discord_client = Arc::new(discord_client);
+    let songbird = Arc::new(songbird);
     let vcs = Arc::new(vcs);
 
-    let songbird = Arc::new(songbird);
-
-    let state = State { vcs, songbird };
+    let state = State {
+        discord_application_id,
+        discord_client,
+        songbird,
+        vcs,
+    };
 
     while let Some(event_res) = next_event.await {
         match event_res {