Add help command

cipher_discord_bot/Cargo.toml

@@ -16,6 +16,7 @@ secrecy = "0.10.3"
 serenity = "0.12.4"
 thiserror = "2.0.11"
 tokio = { version = "1.43.0", features = ["full"] }
+futures = "0.3.31"
 
 [features]
 default = ["mysql", "postgres", "sqlite"]

cipher_discord_bot/src/app/framework.rs

@@ -19,6 +19,7 @@ where
 
     let app_data = AppData {
         repository_provider,
+        qualified_command_names: commands::qualified_command_names(&commands),
     };
 
     let options = FrameworkOptions::<AppData<R>, AppError<R::BackendError>> {

cipher_discord_bot/src/app/mod.rs

@@ -18,6 +18,7 @@ pub enum AppStartError {
 
 pub struct AppData<R> {
     repository_provider: R,
+    qualified_command_names: Vec<String>,
 }
 
 #[derive(Debug, thiserror::Error)]
@@ -61,3 +62,9 @@ where
         self.repository_provider.get().await
     }
 }
+
+impl<R> AppData<R> {
+    pub fn qualified_command_names(&self) -> &[String] {
+        &self.qualified_command_names
+    }
+}

cipher_discord_bot/src/commands/help.rs

@@ -0,0 +1,173 @@
+use futures::Stream;
+use cipher_core::repository::RepositoryProvider;
+use poise::CreateReply;
+use serenity::all::Color;
+use serenity::all::CreateEmbed;
+use serenity::futures::StreamExt;
+
+use crate::app::AppCommand;
+use crate::app::AppContext;
+use crate::app::AppError;
+
+async fn autocomplete_command<'a, R> (
+    ctx: AppContext<'a, R, R::BackendError>,
+    partial: &'a str,
+) -> impl Stream<Item = String> + 'a
+where
+    R: RepositoryProvider,
+{
+    futures::stream::iter(ctx.data().qualified_command_names())
+        .filter(move |name| futures::future::ready(name.contains(partial)))
+        .map(|name| name.to_string())
+}
+
+/// Show help message.
+#[poise::command(slash_command)]
+pub async fn help<R: RepositoryProvider + Sync>(
+    ctx: AppContext<'_, R, R::BackendError>,
+    #[rename = "command"]
+    #[description = "Command to get help for."]
+    #[autocomplete = "autocomplete_command"]
+    option_query: Option<String>,
+    #[description = "Show hidden commands. Defaults to False."] all: Option<bool>,
+    #[description = "Hide reply from other users. Defaults to True."] ephemeral: Option<bool>,
+) -> Result<(), AppError<R::BackendError>> {
+    let embed = if let Some(query) = &option_query {
+        let option_command = poise::find_command(
+            &ctx.framework().options.commands,
+            query,
+            true,
+            &mut Vec::new(),
+        );
+
+        if let Some((command, _, _)) = option_command {
+            command_help_embed(command, all.unwrap_or(false))
+        } else {
+            CreateEmbed::new()
+                .title("Help")
+                .description(format!("Could not find command `/{}`", query))
+                .color(Color::BLURPLE)
+        }
+    } else {
+        root_help_embed(&ctx, all.unwrap_or(false))
+    };
+
+    let reply = CreateReply::default()
+        .embed(embed)
+        .ephemeral(ephemeral.unwrap_or(true));
+
+    ctx.send(reply).await?;
+
+    Ok(())
+}
+
+fn root_help_embed<R>(ctx: &AppContext<'_, R, R::BackendError>, all: bool) -> CreateEmbed
+where
+    R: RepositoryProvider,
+{
+    let mut commands_field_value = String::new();
+    for command in &ctx.framework().options.commands {
+        if !all && command.hide_in_help {
+            continue;
+        }
+
+        commands_field_value.push('`');
+        commands_field_value.push('/');
+        commands_field_value.push_str(&command.name);
+        commands_field_value.push('`');
+
+        if let Some(command_description) = &command.description {
+            commands_field_value.push_str(" - ");
+            commands_field_value.push_str(command_description);
+        }
+
+        commands_field_value.push('\n');
+    }
+    commands_field_value.pop();
+
+    let mut embed = CreateEmbed::new()
+        .title("Help")
+        .color(Color::BLURPLE);
+
+    if !commands_field_value.is_empty() {
+        embed = embed.field("Commands", commands_field_value, false);
+    }
+
+    embed = embed.field("More", "For information on specific commands `/help <command>`.", false);
+
+    embed
+}
+
+fn command_help_embed<R>(command: &AppCommand<R, R::BackendError>, all: bool) -> CreateEmbed
+where
+    R: RepositoryProvider,
+{
+    let mut required_parameters_field_value = String::new();
+    let mut optional_parameters_field_value = String::new();
+    for parameter in &command.parameters {
+        let parameters_field_value = match parameter.required {
+            true => &mut required_parameters_field_value,
+            false => &mut optional_parameters_field_value,
+        };
+
+        parameters_field_value.push('`');
+        parameters_field_value.push_str(&parameter.name);
+        parameters_field_value.push('`');
+
+        if let Some(parameter_description) = &parameter.description {
+            parameters_field_value.push_str(" - ");
+            parameters_field_value.push_str(parameter_description);
+        }
+
+        parameters_field_value.push('\n');
+    }
+    required_parameters_field_value.pop(); // Removes final newline
+    optional_parameters_field_value.pop(); // Removes final newline
+
+    let mut subcommands_field_value = String::new();
+    for subcommand in &command.subcommands {
+        if !all && subcommand.hide_in_help {
+            continue;
+        }
+
+        subcommands_field_value.push('`');
+        subcommands_field_value.push_str(&subcommand.name);
+        subcommands_field_value.push('`');
+
+        if let Some(command_description) = &subcommand.description {
+            subcommands_field_value.push_str(" - ");
+            subcommands_field_value.push_str(command_description);
+        }
+
+        subcommands_field_value.push('\n');
+    }
+    subcommands_field_value.pop(); // Removes final newline
+
+    let mut embed = CreateEmbed::new()
+        .title(format!("Help `/{}`", command.qualified_name))
+        .color(Color::BLURPLE);
+
+    if let Some(category) = &command.category {
+        embed = embed.field("Category", category, false);
+    }
+
+    if !required_parameters_field_value.is_empty() {
+        embed = embed.field("Required Parameters", required_parameters_field_value, false);
+    }
+
+    if !optional_parameters_field_value.is_empty() {
+        embed = embed.field("Optional Parameters", optional_parameters_field_value, false);
+    }
+
+    if !subcommands_field_value.is_empty() {
+        embed = embed.field("Subcommands", subcommands_field_value, false);
+    }
+
+    if let Some(description) = &command.description {
+        embed = embed.description(description);
+    }
+
+    embed = embed.field("More", "For information on specific commands `/help <command>`.", false);
+
+    embed
+}

cipher_discord_bot/src/commands/mod.rs

@@ -2,6 +2,7 @@ use cipher_core::repository::RepositoryProvider;
 
 use crate::app::AppCommand;
 
+mod help;
 mod ping;
 mod profile;
 
@@ -10,7 +11,35 @@ where
     R: RepositoryProvider + Send + Sync + 'static,
 {
     vec![
+        help::help(),
         ping::ping(),
         profile::profile(),
     ]
 }
+
+pub fn qualified_command_names<R>(commands: &[AppCommand<R, R::BackendError>]) -> Vec<String>
+where
+    R: RepositoryProvider,
+{
+    let mut prefix = String::new();
+    let mut names = Vec::new();
+    qualified_command_names_inner(&mut prefix, commands, &mut names);
+    names
+}
+
+fn qualified_command_names_inner<R>(prefix: &mut String, commands: &[AppCommand<R, R::BackendError>], names: &mut Vec<String>)
+where
+    R: RepositoryProvider,
+{
+    for command in commands {
+        if command.subcommands.is_empty() {
+            names.push(format!("{}{}", prefix, command.qualified_name.clone()));
+        } else {
+            let old_len = prefix.len();
+            prefix.push_str(&command.qualified_name);
+            prefix.push(' ');
+            qualified_command_names_inner(prefix, &command.subcommands, names);
+            prefix.truncate(old_len);
+        }
+    }
+}