Add system prompt and tool permission to agent2 (#35781)

Release Notes:

- N/A

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>
Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>

crates/agent2/src/templates.rs

@@ -1,9 +1,9 @@
-use std::sync::Arc;
-
 use anyhow::Result;
+use gpui::SharedString;
 use handlebars::Handlebars;
 use rust_embed::RustEmbed;
 use serde::Serialize;
+use std::sync::Arc;
 
 #[derive(RustEmbed)]
 #[folder = "src/templates"]
@@ -15,6 +15,8 @@ pub struct Templates(Handlebars<'static>);
 impl Templates {
     pub fn new() -> Arc<Self> {
         let mut handlebars = Handlebars::new();
+        handlebars.set_strict_mode(true);
+        handlebars.register_helper("contains", Box::new(contains));
         handlebars.register_embed_templates::<Assets>().unwrap();
         Arc::new(Self(handlebars))
     }
@@ -31,22 +33,6 @@ pub trait Template: Sized {
     }
 }
 
-#[derive(Serialize)]
-pub struct BaseTemplate {
-    pub os: String,
-    pub shell: String,
-    pub worktrees: Vec<WorktreeData>,
-}
-
-impl Template for BaseTemplate {
-    const TEMPLATE_NAME: &'static str = "base.hbs";
-}
-
-#[derive(Serialize)]
-pub struct WorktreeData {
-    pub root_name: String,
-}
-
 #[derive(Serialize)]
 pub struct GlobTemplate {
     pub project_roots: String,
@@ -55,3 +41,56 @@ pub struct GlobTemplate {
 impl Template for GlobTemplate {
     const TEMPLATE_NAME: &'static str = "glob.hbs";
 }
+
+#[derive(Serialize)]
+pub struct SystemPromptTemplate<'a> {
+    #[serde(flatten)]
+    pub project: &'a prompt_store::ProjectContext,
+    pub available_tools: Vec<SharedString>,
+}
+
+impl Template for SystemPromptTemplate<'_> {
+    const TEMPLATE_NAME: &'static str = "system_prompt.hbs";
+}
+
+/// Handlebars helper for checking if an item is in a list
+fn contains(
+    h: &handlebars::Helper,
+    _: &handlebars::Handlebars,
+    _: &handlebars::Context,
+    _: &mut handlebars::RenderContext,
+    out: &mut dyn handlebars::Output,
+) -> handlebars::HelperResult {
+    let list = h
+        .param(0)
+        .and_then(|v| v.value().as_array())
+        .ok_or_else(|| {
+            handlebars::RenderError::new("contains: missing or invalid list parameter")
+        })?;
+    let query = h.param(1).map(|v| v.value()).ok_or_else(|| {
+        handlebars::RenderError::new("contains: missing or invalid query parameter")
+    })?;
+
+    if list.contains(&query) {
+        out.write("true")?;
+    }
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_system_prompt_template() {
+        let project = prompt_store::ProjectContext::default();
+        let template = SystemPromptTemplate {
+            project: &project,
+            available_tools: vec!["echo".into()],
+        };
+        let templates = Templates::new();
+        let rendered = template.render(&templates).unwrap();
+        assert!(rendered.contains("## Fixing Diagnostics"));
+    }
+}