Remove ReactionWatcher (use serenity collector!) and simplify paginate

Cargo.lock

@@ -1975,6 +1975,7 @@ dependencies = [
  "rayon 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "reqwest 0.10.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serenity 0.9.0-rc.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "youmubot-db 0.1.0",
 ]
 

youmubot-prelude/Cargo.toml

@@ -7,12 +7,17 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-serenity = "0.9.0-rc.0"
 anyhow = "1.0"
 async-trait = "0.1"
 futures-util = "0.3"
+tokio = { version = "0.2", features = ["time"] }
 youmubot-db = { path = "../youmubot-db" }
 crossbeam-channel = "0.4"
 reqwest = "0.10"
 rayon = "1"
 chrono = "0.4"
+
+[dependencies.serenity]
+version = "0.9.0-rc.0"
+default-features = true
+features = ["collector"]

youmubot-prelude/src/lib.rs

@@ -4,13 +4,11 @@ use std::sync::Arc;
 pub mod announcer;
 pub mod args;
 pub mod pagination;
-pub mod reaction_watch;
 pub mod setup;
 
 pub use announcer::{Announcer, AnnouncerHandler};
 pub use args::{Duration, UsernameArg};
-pub use pagination::Pagination;
-pub use reaction_watch::{ReactionHandler, ReactionWatcher};
+pub use pagination::paginate;
 
 /// Re-export the anyhow errors
 pub use anyhow::{Error, Result};

youmubot-prelude/src/pagination.rs

@@ -1,157 +1,93 @@
-use crate::{Context, ReactionHandler, ReactionWatcher};
+use crate::{Context, Result};
+use futures_util::{future::Future, StreamExt};
 use serenity::{
-    builder::EditMessage,
-    framework::standard::{CommandError, CommandResult},
+    collector::ReactionAction,
     model::{
-        channel::{Message, Reaction, ReactionType},
+        channel::{Message, ReactionType},
         id::ChannelId,
     },
 };
+use std::convert::TryFrom;
+use tokio::time as tokio_time;
 
 const ARROW_RIGHT: &'static str = "➡️";
 const ARROW_LEFT: &'static str = "⬅️";
 
-impl ReactionWatcher {
-    /// Start a pagination.
-    ///
-    /// Takes a copy of Context (which you can `clone`), a pager (see "Pagination") and a target channel id.
-    /// Pagination will handle all events on adding/removing an "arrow" emoji (⬅️ and ➡️).
-    /// This is a blocking call - it will block the thread until duration is over.
-    pub fn paginate<T: Pagination + Send + 'static>(
-        &self,
-        ctx: Context,
+/// Paginate! with a pager function.
+/// If awaited, will block until everything is done.
+pub async fn paginate<'a, T, F>(
+    mut pager: T,
+    ctx: &'a Context,
     channel: ChannelId,
-        pager: T,
-        duration: std::time::Duration,
-    ) -> CommandResult {
-        let handler = PaginationHandler::new(pager, ctx, channel)?;
-        self.handle_reactions(handler, duration, |_| {});
-        Ok(())
-    }
-
-    /// A version of `paginate` that compiles for closures.
-    ///
-    /// A workaround until https://github.com/rust-lang/rust/issues/36582 is solved.
-    pub fn paginate_fn<T>(
-        &self,
-        ctx: Context,
-        channel: ChannelId,
-        pager: T,
-        duration: std::time::Duration,
-    ) -> CommandResult
-    where
-        T: for<'a> FnMut(u8, &'a mut EditMessage) -> (&'a mut EditMessage, CommandResult)
-            + Send
-            + 'static,
-    {
-        self.paginate(ctx, channel, pager, duration)
-    }
-}
-
-/// Pagination allows the bot to display content in multiple pages.
-///
-/// You need to implement the "render_page" function, which takes a dummy content and
-/// embed assigning function.
-/// Pagination is automatically implemented for functions with the same signature as `render_page`.
-///
-/// Pages start at 0.
-pub trait Pagination {
-    /// Render a page.
-    ///
-    /// This would either create or edit a message, but you should not be worry about it.
-    fn render_page<'a>(
-        &mut self,
-        page: u8,
-        target: &'a mut EditMessage,
-    ) -> (&'a mut EditMessage, CommandResult);
-}
-
-impl<T> Pagination for T
+    timeout: std::time::Duration,
+) -> Result<()>
 where
-    T: for<'a> FnMut(u8, &'a mut EditMessage) -> (&'a mut EditMessage, CommandResult),
+    T: FnMut(u8, &Context, &Message) -> F,
+    F: Future<Output = Result<bool>>,
 {
-    fn render_page<'a>(
-        &mut self,
-        page: u8,
-        target: &'a mut EditMessage,
-    ) -> (&'a mut EditMessage, CommandResult) {
-        self(page, target)
-    }
-}
-
-struct PaginationHandler<T: Pagination> {
-    pager: T,
-    message: Message,
-    page: u8,
-    ctx: Context,
-}
-
-impl<T: Pagination> PaginationHandler<T> {
-    pub fn new(pager: T, mut ctx: Context, channel: ChannelId) -> Result<Self, CommandError> {
-        let message = channel.send_message(&mut ctx, |e| {
-            e.content("Youmu is loading the first page...")
-        })?;
+    let message = channel
+        .send_message(&ctx, |e| e.content("Youmu is loading the first page..."))
+        .await?;
     // React to the message
-        message.react(&mut ctx, ARROW_LEFT)?;
-        message.react(&mut ctx, ARROW_RIGHT)?;
-        let mut p = Self {
-            pager,
-            message: message.clone(),
-            page: 0,
-            ctx,
+    message
+        .react(&ctx, ReactionType::try_from(ARROW_LEFT)?)
+        .await?;
+    message
+        .react(&ctx, ReactionType::try_from(ARROW_RIGHT)?)
+        .await?;
+    // Build a reaction collector
+    let mut reaction_collector = message.await_reactions(&ctx).await;
+    let mut page = 0;
+
+    // Loop the handler function.
+    let res: Result<()> = loop {
+        match tokio_time::timeout(timeout, reaction_collector.next()).await {
+            Err(_) => break Ok(()),
+            Ok(None) => break Ok(()),
+            Ok(Some(reaction)) => {
+                page = match handle_reaction(page, &mut pager, ctx, &message, &reaction).await {
+                    Ok(v) => v,
+                    Err(e) => break Err(e),
                 };
-        p.call_pager()?;
-        Ok(p)
             }
-}
+        }
+    };
+
+    message.react(&ctx, '🛑').await?;
 
-impl<T: Pagination> PaginationHandler<T> {
-    /// Call the pager, log the error (if any).
-    fn call_pager(&mut self) -> CommandResult {
-        let mut res: CommandResult = Ok(());
-        let mut msg = self.message.clone();
-        msg.edit(self.ctx.http.clone(), |e| {
-            let (e, r) = self.pager.render_page(self.page, e);
-            res = r;
-            e
-        })?;
-        self.message = msg;
     res
-    }
 }
 
-impl<T: Pagination> Drop for PaginationHandler<T> {
-    fn drop(&mut self) {
-        self.message.react(&self.ctx, "🛑").ok();
-    }
-}
-
-impl<T: Pagination> ReactionHandler for PaginationHandler<T> {
-    fn handle_reaction(&mut self, reaction: &Reaction, _is_add: bool) -> CommandResult {
-        if reaction.message_id != self.message.id {
-            return Ok(());
-        }
+// Handle the reaction and return a new page number.
+async fn handle_reaction<'a, T, F>(
+    page: u8,
+    pager: &mut T,
+    ctx: &'a Context,
+    message: &'_ Message,
+    reaction: &ReactionAction,
+) -> Result<u8>
+where
+    T: for<'n, 'm> FnMut(u8, &'n Context, &'m Message) -> F,
+    F: Future<Output = Result<bool>>,
+{
+    let reaction = match reaction {
+        ReactionAction::Added(v) | ReactionAction::Removed(v) => v,
+    };
     match &reaction.emoji {
         ReactionType::Unicode(ref s) => match s.as_str() {
-                ARROW_LEFT if self.page == 0 => return Ok(()),
-                ARROW_LEFT => {
-                    self.page -= 1;
-                    if let Err(e) = self.call_pager() {
-                        self.page += 1;
-                        return Err(e);
-                    }
-                }
-                ARROW_RIGHT => {
-                    self.page += 1;
-                    if let Err(e) = self.call_pager() {
-                        self.page -= 1;
-                        return Err(e);
-                    }
-                }
-                _ => (),
+            ARROW_LEFT if page == 0 => Ok(page),
+            ARROW_LEFT => Ok(if pager(page - 1, ctx, message).await? {
+                page - 1
+            } else {
+                page
+            }),
+            ARROW_RIGHT => Ok(if pager(page + 1, ctx, message).await? {
+                page + 1
+            } else {
+                page
+            }),
+            _ => Ok(page),
         },
-            _ => (),
-        }
-        Ok(())
+        _ => Ok(page),
     }
 }

youmubot-prelude/src/reaction_watch.rs

@@ -1,105 +0,0 @@
-use crossbeam_channel::{after, bounded, select, Sender};
-use serenity::{framework::standard::CommandResult, model::channel::Reaction, prelude::*};
-use std::sync::{Arc, Mutex};
-
-/// Handles a reaction.
-///
-/// Every handler needs an expire time too.
-pub trait ReactionHandler {
-    /// Handle a reaction. This is fired on EVERY reaction.
-    /// You do the filtering yourself.
-    ///
-    /// If `is_added` is false, the reaction was removed instead of added.
-    fn handle_reaction(&mut self, reaction: &Reaction, is_added: bool) -> CommandResult;
-}
-
-impl<T> ReactionHandler for T
-where
-    T: FnMut(&Reaction, bool) -> CommandResult,
-{
-    fn handle_reaction(&mut self, reaction: &Reaction, is_added: bool) -> CommandResult {
-        self(reaction, is_added)
-    }
-}
-
-/// The store for a set of dynamic reaction handlers.
-#[derive(Debug, Clone)]
-pub struct ReactionWatcher {
-    channels: Arc<Mutex<Vec<Sender<(Arc<Reaction>, bool)>>>>,
-}
-
-impl TypeMapKey for ReactionWatcher {
-    type Value = ReactionWatcher;
-}
-
-impl ReactionWatcher {
-    /// Create a new ReactionWatcher.
-    pub fn new() -> Self {
-        Self {
-            channels: Arc::new(Mutex::new(vec![])),
-        }
-    }
-    /// Send a reaction.
-    /// If `is_added` is false, the reaction was removed.
-    pub fn send(&self, r: Reaction, is_added: bool) {
-        let r = Arc::new(r);
-        self.channels
-            .lock()
-            .expect("Poisoned!")
-            .retain(|e| e.send((r.clone(), is_added)).is_ok());
-    }
-    /// React! to a series of reaction
-    ///
-    /// The reactions stop after `duration` of idle.
-    pub fn handle_reactions<H: ReactionHandler + Send + 'static>(
-        &self,
-        mut h: H,
-        duration: std::time::Duration,
-        callback: impl FnOnce(H) -> () + Send + 'static,
-    ) {
-        let (send, reactions) = bounded(0);
-        {
-            self.channels.lock().expect("Poisoned!").push(send);
-        }
-        std::thread::spawn(move || {
-            loop {
-                let timeout = after(duration);
-                let r = select! {
-                    recv(reactions) -> r => { let (r, is_added) = r.unwrap(); h.handle_reaction(&*r, is_added) },
-                    recv(timeout) -> _ => break,
-                };
-                if let Err(v) = r {
-                    dbg!(v);
-                }
-            }
-            callback(h)
-        });
-    }
-    /// React! to a series of reaction
-    ///
-    /// The handler will stop after `duration` no matter what.
-    pub fn handle_reactions_timed<H: ReactionHandler + Send + 'static>(
-        &self,
-        mut h: H,
-        duration: std::time::Duration,
-        callback: impl FnOnce(H) -> () + Send + 'static,
-    ) {
-        let (send, reactions) = bounded(0);
-        {
-            self.channels.lock().expect("Poisoned!").push(send);
-        }
-        std::thread::spawn(move || {
-            let timeout = after(duration);
-            loop {
-                let r = select! {
-                    recv(reactions) -> r => { let (r, is_added) = r.unwrap(); h.handle_reaction(&*r, is_added) },
-                    recv(timeout) -> _ => break,
-                };
-                if let Err(v) = r {
-                    dbg!(v);
-                }
-            }
-            callback(h);
-        });
-    }
-}