Add ability to attach rules as context (#29109)

Release Notes:

- agent: Added support for adding rules as context.

crates/agent/src/context_picker/rules_context_picker.rs

@@ -0,0 +1,248 @@
+use std::sync::Arc;
+use std::sync::atomic::AtomicBool;
+
+use anyhow::anyhow;
+use gpui::{App, DismissEvent, Entity, FocusHandle, Focusable, Task, WeakEntity};
+use picker::{Picker, PickerDelegate};
+use prompt_store::{PromptId, UserPromptId};
+use ui::{ListItem, prelude::*};
+
+use crate::context::RULES_ICON;
+use crate::context_picker::ContextPicker;
+use crate::context_store::{self, ContextStore};
+use crate::thread_store::ThreadStore;
+
+pub struct RulesContextPicker {
+    picker: Entity<Picker<RulesContextPickerDelegate>>,
+}
+
+impl RulesContextPicker {
+    pub fn new(
+        thread_store: WeakEntity<ThreadStore>,
+        context_picker: WeakEntity<ContextPicker>,
+        context_store: WeakEntity<context_store::ContextStore>,
+        window: &mut Window,
+        cx: &mut Context<Self>,
+    ) -> Self {
+        let delegate = RulesContextPickerDelegate::new(thread_store, context_picker, context_store);
+        let picker = cx.new(|cx| Picker::uniform_list(delegate, window, cx));
+
+        RulesContextPicker { picker }
+    }
+}
+
+impl Focusable for RulesContextPicker {
+    fn focus_handle(&self, cx: &App) -> FocusHandle {
+        self.picker.focus_handle(cx)
+    }
+}
+
+impl Render for RulesContextPicker {
+    fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
+        self.picker.clone()
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct RulesContextEntry {
+    pub prompt_id: UserPromptId,
+    pub title: SharedString,
+}
+
+pub struct RulesContextPickerDelegate {
+    thread_store: WeakEntity<ThreadStore>,
+    context_picker: WeakEntity<ContextPicker>,
+    context_store: WeakEntity<context_store::ContextStore>,
+    matches: Vec<RulesContextEntry>,
+    selected_index: usize,
+}
+
+impl RulesContextPickerDelegate {
+    pub fn new(
+        thread_store: WeakEntity<ThreadStore>,
+        context_picker: WeakEntity<ContextPicker>,
+        context_store: WeakEntity<context_store::ContextStore>,
+    ) -> Self {
+        RulesContextPickerDelegate {
+            thread_store,
+            context_picker,
+            context_store,
+            matches: Vec::new(),
+            selected_index: 0,
+        }
+    }
+}
+
+impl PickerDelegate for RulesContextPickerDelegate {
+    type ListItem = ListItem;
+
+    fn match_count(&self) -> usize {
+        self.matches.len()
+    }
+
+    fn selected_index(&self) -> usize {
+        self.selected_index
+    }
+
+    fn set_selected_index(
+        &mut self,
+        ix: usize,
+        _window: &mut Window,
+        _cx: &mut Context<Picker<Self>>,
+    ) {
+        self.selected_index = ix;
+    }
+
+    fn placeholder_text(&self, _window: &mut Window, _cx: &mut App) -> Arc<str> {
+        "Search available rules…".into()
+    }
+
+    fn update_matches(
+        &mut self,
+        query: String,
+        window: &mut Window,
+        cx: &mut Context<Picker<Self>>,
+    ) -> Task<()> {
+        let Some(thread_store) = self.thread_store.upgrade() else {
+            return Task::ready(());
+        };
+
+        let search_task = search_rules(query, Arc::new(AtomicBool::default()), thread_store, cx);
+        cx.spawn_in(window, async move |this, cx| {
+            let matches = search_task.await;
+            this.update(cx, |this, cx| {
+                this.delegate.matches = matches;
+                this.delegate.selected_index = 0;
+                cx.notify();
+            })
+            .ok();
+        })
+    }
+
+    fn confirm(&mut self, _secondary: bool, _window: &mut Window, cx: &mut Context<Picker<Self>>) {
+        let Some(entry) = self.matches.get(self.selected_index) else {
+            return;
+        };
+
+        let Some(thread_store) = self.thread_store.upgrade() else {
+            return;
+        };
+
+        let prompt_id = entry.prompt_id;
+
+        let load_rules_task = thread_store.update(cx, |thread_store, cx| {
+            thread_store.load_rules(prompt_id, cx)
+        });
+
+        cx.spawn(async move |this, cx| {
+            let (metadata, text) = load_rules_task.await?;
+            let Some(title) = metadata.title else {
+                return Err(anyhow!("Encountered user rule with no title when attempting to add it to agent context."));
+            };
+            this.update(cx, |this, cx| {
+                this.delegate
+                    .context_store
+                    .update(cx, |context_store, cx| {
+                        context_store.add_rules(prompt_id, title, text, true, cx)
+                    })
+                    .ok();
+            })
+        })
+        .detach_and_log_err(cx);
+    }
+
+    fn dismissed(&mut self, _window: &mut Window, cx: &mut Context<Picker<Self>>) {
+        self.context_picker
+            .update(cx, |_, cx| {
+                cx.emit(DismissEvent);
+            })
+            .ok();
+    }
+
+    fn render_match(
+        &self,
+        ix: usize,
+        selected: bool,
+        _window: &mut Window,
+        cx: &mut Context<Picker<Self>>,
+    ) -> Option<Self::ListItem> {
+        let thread = &self.matches[ix];
+
+        Some(ListItem::new(ix).inset(true).toggle_state(selected).child(
+            render_thread_context_entry(thread, self.context_store.clone(), cx),
+        ))
+    }
+}
+
+pub fn render_thread_context_entry(
+    user_rules: &RulesContextEntry,
+    context_store: WeakEntity<ContextStore>,
+    cx: &mut App,
+) -> Div {
+    let added = context_store.upgrade().map_or(false, |ctx_store| {
+        ctx_store
+            .read(cx)
+            .includes_user_rules(&user_rules.prompt_id)
+            .is_some()
+    });
+
+    h_flex()
+        .gap_1p5()
+        .w_full()
+        .justify_between()
+        .child(
+            h_flex()
+                .gap_1p5()
+                .max_w_72()
+                .child(
+                    Icon::new(RULES_ICON)
+                        .size(IconSize::XSmall)
+                        .color(Color::Muted),
+                )
+                .child(Label::new(user_rules.title.clone()).truncate()),
+        )
+        .when(added, |el| {
+            el.child(
+                h_flex()
+                    .gap_1()
+                    .child(
+                        Icon::new(IconName::Check)
+                            .size(IconSize::Small)
+                            .color(Color::Success),
+                    )
+                    .child(Label::new("Added").size(LabelSize::Small)),
+            )
+        })
+}
+
+pub(crate) fn search_rules(
+    query: String,
+    cancellation_flag: Arc<AtomicBool>,
+    thread_store: Entity<ThreadStore>,
+    cx: &mut App,
+) -> Task<Vec<RulesContextEntry>> {
+    let Some(prompt_store) = thread_store.read(cx).prompt_store() else {
+        return Task::ready(vec![]);
+    };
+    let search_task = prompt_store.read(cx).search(query, cancellation_flag, cx);
+    cx.background_spawn(async move {
+        search_task
+            .await
+            .into_iter()
+            .flat_map(|metadata| {
+                // Default prompts are filtered out as they are automatically included.
+                if metadata.default {
+                    None
+                } else {
+                    match metadata.id {
+                        PromptId::EditWorkflow => None,
+                        PromptId::User { uuid } => Some(RulesContextEntry {
+                            prompt_id: uuid,
+                            title: metadata.title?,
+                        }),
+                    }
+                }
+            })
+            .collect::<Vec<_>>()
+    })
+}