Add .help method to Commands and generate fancy new help menu and help commands

Author: technetos

src/commands.rs

@@ -17,15 +17,15 @@ pub struct Args<'m> {
 pub(crate) struct Commands {
     state_machine: StateMachine,
     client: HttpClient,
-    menu: Option<String>,
+    menu: HashMap<&'static str, &'static str>,
 }
 
 impl Commands {
     pub(crate) fn new() -> Self {
         Self {
             state_machine: StateMachine::new(),
             client: HttpClient::new(),
-            menu: Some(String::new()),
+            menu: HashMap::new(),
         }
     }
 
@@ -100,16 +100,27 @@ impl Commands {
             self.state_machine.set_final_state(state);
             self.state_machine.set_handler(state, handler.clone());
         }
+    }
+
+    pub(crate) fn help(
+        &mut self,
+        cmd: &'static str,
+        desc: &'static str,
+        handler: impl Fn(Args) -> Result<()> + Send + Sync + 'static,
+    ) {
+        let base_cmd = &cmd[1..];
+        info!("Adding command ?help {}", &base_cmd);
+        let mut state = 0;
+
+        self.menu.insert(cmd, desc);
+        state = add_help_menu(&mut self.state_machine, base_cmd, state);
 
-        self.menu.as_mut().map(|menu| {
-            *menu += command;
-            *menu += "\n"
-        });
+        self.state_machine.set_final_state(state);
+        self.state_machine.set_handler(state, Arc::new(handler));
     }
 
-    pub(crate) fn menu(&mut self) -> Option<String> {
-        self.menu.as_mut().map(|menu| *menu += "?help\n");
-        self.menu.take()
+    pub(crate) fn menu(&mut self) -> &HashMap<&'static str, &'static str> {
+        &self.menu
     }
 
     pub(crate) fn execute<'m>(&'m self, cx: Context, msg: Message) {
@@ -156,6 +167,24 @@ fn add_space(state_machine: &mut StateMachine, mut state: usize, i: usize) -> us
     state
 }
 
+fn add_help_menu(
+    mut state_machine: &mut StateMachine,
+    cmd: &'static str,
+    mut state: usize,
+) -> usize {
+    state = state_machine.add(state, CharacterSet::from_char('?'));
+    state = state_machine.add(state, CharacterSet::from_char('h'));
+    state = state_machine.add(state, CharacterSet::from_char('e'));
+    state = state_machine.add(state, CharacterSet::from_char('l'));
+    state = state_machine.add(state, CharacterSet::from_char('p'));
+    state = add_space(&mut state_machine, state, 1);
+    cmd.chars().for_each(|ch| {
+        state = state_machine.add(state, CharacterSet::from_char(ch));
+    });
+
+    state
+}
+
 fn add_dynamic_segment(
     state_machine: &mut StateMachine,
     name: &'static str,

src/main.rs

@@ -24,6 +24,7 @@ use diesel::prelude::*;
 use envy;
 use serde::Deserialize;
 use serenity::{model::prelude::*, prelude::*};
+use std::collections::HashMap;
 
 pub(crate) type Result = crate::commands::Result<()>;
 
@@ -90,19 +91,19 @@ fn app() -> Result {
         // Tags
         cmds.add("?tags delete {key}", tags::delete);
         cmds.add("?tags create {key} value...", tags::post);
-        cmds.add("?tags help", tags::help);
+        cmds.add("?tags {key}", tags::get);
         cmds.add("?tags", tags::get_all);
-        cmds.add("?tag {key}", tags::get);
+        cmds.help("?tags", "A key value store", tags::help);
     }
 
     if config.crates {
         // crates.io
-        cmds.add("?crate help", crates::help);
         cmds.add("?crate query...", crates::search);
+        cmds.help("?crate", "Lookup crates on crates.io", crates::help);
 
         // docs.rs
-        cmds.add("?docs help", crates::doc_help);
         cmds.add("?docs query...", crates::doc_search);
+        cmds.help("?docs", "Lookup documentation", crates::doc_help);
     }
 
     // Slow mode.
@@ -113,14 +114,13 @@ fn app() -> Result {
     cmds.add("?kick {user}", api::kick);
 
     // Ban
-    cmds.add("?ban help", ban::help);
     cmds.add("?ban {user} {hours} reason...", ban::temp_ban);
+    cmds.help("?ban", "Temporarily ban a user from the guild", ban::help);
 
     // Post the welcome message to the welcome channel.
     cmds.add("?CoC {channel}", welcome::post_message);
 
-    let menu = cmds.menu().unwrap();
-
+    let menu = main_menu(cmds.menu());
     cmds.add("?help", move |args: Args| {
         api::send_reply(&args, &format!("```{}```", &menu))?;
         Ok(())
@@ -137,6 +137,25 @@ fn app() -> Result {
     Ok(())
 }
 
+fn main_menu(commands: &HashMap<&str, &str>) -> String {
+    let mut menu = format!("Commands:\n");
+
+    menu = commands
+        .iter()
+        .fold(menu, |mut menu, (base_cmd, description)| {
+            menu += &format!(
+                "\t{cmd:<8}{desc}\n",
+                cmd = base_cmd,
+                desc = description
+            );
+            menu
+        });
+
+    menu += &format!("\t{help:<8}This menu\n", help = "?help");
+    menu += "\nType ?help command for more info on a command.";
+    menu
+}
+
 fn main() {
     env_logger::init();