WIP: implement HELP

sable_ircd/src/command/client_command.rs

@@ -52,6 +52,8 @@ pub struct ClientCommand {
     pub args: Vec<String>,
     /// Tags provided by the client
     pub tags: InboundTagSet,
+    /// Command help information
+    //cmd_help: CommandHelp,
 
     // The response sink. labeled-response requires that this lives for the whole
     // lifetime of the command, not just the handler duration, because even translated

sable_ircd/src/command/dispatcher.rs

@@ -12,6 +12,7 @@ pub struct CommandRegistration {
     pub(super) command: &'static str,
     pub(super) dispatcher: Option<&'static str>,
     pub(super) handler: CommandHandlerWrapper,
+    pub(super) help: Vec<&'static str>,
 }
 
 /// A command dispatcher. Collects registered command handlers and allows lookup by

sable_ircd/src/command/handlers/help.rs

@@ -0,0 +1,62 @@
+use super::*;
+
+use std::collections::HashMap;
+
+use itertools::Itertools;
+
+#[command_handler("HELP")]
+/// Syntax: HELP [<subject>]
+fn help_handler(
+    response: &dyn CommandResponse,
+    server: &ClientServer,
+    subject: Option<&str>,
+) -> CommandResult {
+    // TODO: oper help? (and if oper help is on the same command, UHELP like solanum?)
+    // TODO: get this from doc comments
+    // TODO: how to add non-command topics?
+    // TODO: or btreemap (presorted)?
+    //let mut help_topics = HashMap::from([
+    //    ("HELP".to_string(), "HELP [<subject>]\n\nGet information about subject.\nIf subject is not given, list available topics."),
+    //    ("INFO".to_string(), "INFO\n\nShow information about this server."),
+    //    ("asdfadsf".to_string(), "INFO\n\nShow information about this server."),
+    //    ("asdf".to_string(), "INFO\n\nShow information about this server."),
+    //    ("hfasdfxdv".to_string(), "INFO\n\nShow information about this server."),
+    //    ("dfadfNFO".to_string(), "INFO\n\nShow information about this server."),
+    //    ("dfdfdf".to_string(), "INFO\n\nShow information about this server."),
+    //    ("nxcnjvxc".to_string(), "INFO\n\nShow information about this server."),
+    //]);
+
+    match subject {
+        Some(s) => {
+            let subject = s.to_ascii_uppercase();
+            let subject = match subject.split_once(' ') {
+                Some((subj, _)) => subj.to_string(),
+                None => subject,
+            };
+
+            for reg in inventory::iter::<CommandRegistration> {
+                if reg.command == subject {
+                    let mut lines = reg.help.iter();
+                    response.numeric(make_numeric!(HelpStart, &subject, lines.next().unwrap_or(&subject.as_str())));
+                    for line in lines {
+                        response.numeric(make_numeric!(HelpText, &subject, line));
+                    }
+                    response.numeric(make_numeric!(EndOfHelp, &subject));
+                } else {
+                    response.numeric(make_numeric!(HelpNotFound, &subject))
+                }
+            }
+        },
+        None => {
+            let subject = "*";
+            response.numeric(make_numeric!(HelpStart, subject, "Available help topics:"));
+            response.numeric(make_numeric!(HelpText, subject, ""));
+            for chunk in &inventory::iter::<CommandRegistration>.into_iter().map(|v| v.command.to_ascii_uppercase()).chunks(4) {
+                let line = format!("{:16}", chunk.format(" "));
+                response.numeric(make_numeric!(HelpText, subject, &line));
+            }
+            response.numeric(make_numeric!(EndOfHelp, subject));
+        },
+    };
+    Ok(())
+}

sable_ircd/src/command/mod.rs

@@ -42,6 +42,7 @@ mod handlers {
     mod ban;
     mod cap;
     mod chathistory;
+    mod help;
     mod invite;
     mod join;
     mod kick;

sable_ircd/src/messages/numeric.rs

@@ -67,6 +67,10 @@ define_messages! {
 
     381(YoureOper)              => { ()                         => "You are now an IRC operator" },
 
+    704(HelpStart)              => { (subj: &str, line: &str)   => "{subj} :{line}" },
+    705(HelpText)               => { (subj: &str, line: &str)   => "{subj} :{line}" },
+    706(EndOfHelp)              => { (subj: &str)               => "{subj} :End of /HELP" },
+
 
     401(NoSuchTarget)           => { (unknown: &str)            => "{unknown} :No such nick/channel" },
     402(NoSuchServer)           => { (server_name: &ServerName) => "{server_name} :No such server" },
@@ -122,6 +126,8 @@ define_messages! {
 
     440(ServicesNotAvailable) => { () => ":Services are not available"},
 
+    524(HelpNotFound)           => { (subj: &str)               => "{subj} :No help available on this topic" },
+
     // https://ircv3.net/specs/extensions/monitor
     730(MonOnline)          => { (content: &str )               => ":{content}" },
     731(MonOffline)         => { (content: &str )               => ":{content}" },

sable_macros/src/command_handler.rs

@@ -2,7 +2,7 @@ use super::*;
 
 use quote::{quote, quote_spanned};
 use syn::{
-    parenthesized, parse::Parse, parse_macro_input, token::In, Ident, ItemFn, LitStr, Token,
+    parenthesized, parse::Parse, parse_macro_input, token::In, Ident, ItemFn, LitStr, Meta, MetaList, MetaNameValue, Token
 };
 
 struct CommandHandlerAttr {
@@ -43,6 +43,17 @@ pub fn command_handler(attr: TokenStream, item: TokenStream) -> TokenStream {
         }
     }
 
+    let help = item.attrs.clone().into_iter().filter(|a| a.path.is_ident("doc")).filter_map(|a| {
+        match a.parse_meta() {
+            Ok(Meta::NameValue(MetaNameValue { lit: syn::Lit::Str(s), .. })) => Some(s),
+            //Ok(Meta::List(MetaList { path, .. })) if path.is_ident("hidden") => {
+            //    hidden = true;
+            //    None
+            //},
+            _ => None,
+        }
+    }).collect::<Vec<LitStr>>();
+
     let dispatcher = match input.dispatcher {
         Some(name) => quote!( Some( #name ) ),
         None => quote!(None),
@@ -91,7 +102,8 @@ pub fn command_handler(attr: TokenStream, item: TokenStream) -> TokenStream {
             inventory::submit!(crate::command::CommandRegistration {
                 command: #command_name,
                 dispatcher: #dispatcher,
-                handler: call_proxy
+                handler: call_proxy,
+                help: [#(#help,)*],
             });
         }
     ).into()