Start work on chat mentions

crates/collab_ui/src/chat_panel/message_editor.rs

@@ -0,0 +1,218 @@
+use channel::{Channel, ChannelStore};
+use client::UserId;
+use collections::HashMap;
+use editor::{AnchorRangeExt, Editor};
+use gpui::{
+    elements::ChildView, AnyElement, AsyncAppContext, Element, Entity, ModelHandle, Task, View,
+    ViewContext, ViewHandle, WeakViewHandle,
+};
+use language::{language_settings::SoftWrap, Buffer, BufferSnapshot, LanguageRegistry};
+use lazy_static::lazy_static;
+use project::search::SearchQuery;
+use std::{ops::Range, sync::Arc, time::Duration};
+
+const MENTIONS_DEBOUNCE_INTERVAL: Duration = Duration::from_millis(50);
+
+lazy_static! {
+    static ref MENTIONS_SEARCH: SearchQuery = SearchQuery::regex(
+        "@[-_\\w]+",
+        false,
+        false,
+        Default::default(),
+        Default::default()
+    )
+    .unwrap();
+}
+
+pub struct MessageEditor {
+    pub editor: ViewHandle<Editor>,
+    channel_store: ModelHandle<ChannelStore>,
+    users: HashMap<String, UserId>,
+    mentions: Vec<UserId>,
+    mentions_task: Option<Task<()>>,
+    channel: Option<Arc<Channel>>,
+}
+
+pub struct ChatMessage {
+    pub text: String,
+    pub mentions: Vec<(Range<usize>, UserId)>,
+}
+
+impl MessageEditor {
+    pub fn new(
+        language_registry: Arc<LanguageRegistry>,
+        channel_store: ModelHandle<ChannelStore>,
+        editor: ViewHandle<Editor>,
+        cx: &mut ViewContext<Self>,
+    ) -> Self {
+        editor.update(cx, |editor, cx| {
+            editor.set_soft_wrap_mode(SoftWrap::EditorWidth, cx);
+        });
+
+        let buffer = editor
+            .read(cx)
+            .buffer()
+            .read(cx)
+            .as_singleton()
+            .expect("message editor must be singleton");
+
+        cx.subscribe(&buffer, Self::on_buffer_event).detach();
+        cx.subscribe(&editor, |_, _, event, cx| {
+            if let editor::Event::Focused = event {
+                eprintln!("focused");
+                cx.notify()
+            }
+        })
+        .detach();
+
+        let markdown = language_registry.language_for_name("Markdown");
+        cx.app_context()
+            .spawn(|mut cx| async move {
+                let markdown = markdown.await?;
+                buffer.update(&mut cx, |buffer, cx| {
+                    buffer.set_language(Some(markdown), cx)
+                });
+                anyhow::Ok(())
+            })
+            .detach_and_log_err(cx);
+
+        Self {
+            editor,
+            channel_store,
+            users: HashMap::default(),
+            channel: None,
+            mentions: Vec::new(),
+            mentions_task: None,
+        }
+    }
+
+    pub fn set_channel(&mut self, channel: Arc<Channel>, cx: &mut ViewContext<Self>) {
+        self.editor.update(cx, |editor, cx| {
+            editor.set_placeholder_text(format!("Message #{}", channel.name), cx);
+        });
+        self.channel = Some(channel);
+        self.refresh_users(cx);
+    }
+
+    pub fn refresh_users(&mut self, cx: &mut ViewContext<Self>) {
+        if let Some(channel) = &self.channel {
+            let members = self.channel_store.update(cx, |store, cx| {
+                store.get_channel_member_details(channel.id, cx)
+            });
+            cx.spawn(|this, mut cx| async move {
+                let members = members.await?;
+                this.update(&mut cx, |this, _| {
+                    this.users.clear();
+                    this.users.extend(
+                        members
+                            .into_iter()
+                            .map(|member| (member.user.github_login.clone(), member.user.id)),
+                    );
+                })?;
+                anyhow::Ok(())
+            })
+            .detach_and_log_err(cx);
+        }
+    }
+
+    pub fn take_message(&mut self, cx: &mut ViewContext<Self>) -> ChatMessage {
+        self.editor.update(cx, |editor, cx| {
+            let highlights = editor.text_highlights::<Self>(cx);
+            let text = editor.text(cx);
+            let snapshot = editor.buffer().read(cx).snapshot(cx);
+            let mentions = if let Some((_, ranges)) = highlights {
+                ranges
+                    .iter()
+                    .map(|range| range.to_offset(&snapshot))
+                    .zip(self.mentions.iter().copied())
+                    .collect()
+            } else {
+                Vec::new()
+            };
+
+            editor.clear(cx);
+            self.mentions.clear();
+
+            ChatMessage { text, mentions }
+        })
+    }
+
+    fn on_buffer_event(
+        &mut self,
+        buffer: ModelHandle<Buffer>,
+        event: &language::Event,
+        cx: &mut ViewContext<Self>,
+    ) {
+        if let language::Event::Reparsed | language::Event::Edited = event {
+            let buffer = buffer.read(cx).snapshot();
+            self.mentions_task = Some(cx.spawn(|this, cx| async move {
+                cx.background().timer(MENTIONS_DEBOUNCE_INTERVAL).await;
+                Self::find_mentions(this, buffer, cx).await;
+            }));
+        }
+    }
+
+    async fn find_mentions(
+        this: WeakViewHandle<MessageEditor>,
+        buffer: BufferSnapshot,
+        mut cx: AsyncAppContext,
+    ) {
+        let (buffer, ranges) = cx
+            .background()
+            .spawn(async move {
+                let ranges = MENTIONS_SEARCH.search(&buffer, None).await;
+                (buffer, ranges)
+            })
+            .await;
+
+        this.update(&mut cx, |this, cx| {
+            let mut anchor_ranges = Vec::new();
+            let mut mentioned_user_ids = Vec::new();
+            let mut text = String::new();
+
+            this.editor.update(cx, |editor, cx| {
+                let multi_buffer = editor.buffer().read(cx).snapshot(cx);
+                for range in ranges {
+                    text.clear();
+                    text.extend(buffer.text_for_range(range.clone()));
+                    if let Some(username) = text.strip_prefix("@") {
+                        if let Some(user_id) = this.users.get(username) {
+                            let start = multi_buffer.anchor_after(range.start);
+                            let end = multi_buffer.anchor_after(range.end);
+
+                            mentioned_user_ids.push(*user_id);
+                            anchor_ranges.push(start..end);
+                        }
+                    }
+                }
+
+                editor.clear_highlights::<Self>(cx);
+                editor.highlight_text::<Self>(
+                    anchor_ranges,
+                    theme::current(cx).chat_panel.mention_highlight,
+                    cx,
+                )
+            });
+
+            this.mentions = mentioned_user_ids;
+            this.mentions_task.take();
+        })
+        .ok();
+    }
+}
+
+impl Entity for MessageEditor {
+    type Event = ();
+}
+
+impl View for MessageEditor {
+    fn render(&mut self, cx: &mut ViewContext<'_, '_, Self>) -> AnyElement<Self> {
+        ChildView::new(&self.editor, cx).into_any()
+    }
+
+    fn focus_in(&mut self, _: gpui::AnyViewHandle, cx: &mut ViewContext<Self>) {
+        if cx.is_self_focused() {
+            cx.focus(&self.editor);
+        }
+    }
+}