feat(templates): avanterules filetype support (closes #254) (#466)

Signed-off-by: Aaron Pham <contact@aarnphm.xyz>

crates/avante-templates/src/lib.rs

@@ -0,0 +1,91 @@
+use minijinja::{context, path_loader, Environment};
+use mlua::prelude::*;
+use serde::{Deserialize, Serialize};
+use std::sync::{Arc, Mutex};
+
+struct State<'a> {
+    environment: Mutex<Option<Environment<'a>>>,
+}
+
+impl<'a> State<'a> {
+    fn new() -> Self {
+        State {
+            environment: Mutex::new(None),
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+struct TemplateContext {
+    use_xml_format: bool,
+    ask: bool,
+    question: String,
+    code_lang: String,
+    file_content: String,
+    selected_code: Option<String>,
+    project_context: Option<String>,
+    memory_context: Option<String>,
+}
+
+// Given the file name registered after add, the context table in Lua, resulted in a formatted
+// Lua string
+fn render(state: &State, template: String, context: TemplateContext) -> LuaResult<String> {
+    let environment = state.environment.lock().unwrap();
+    match environment.as_ref() {
+        Some(environment) => {
+            let template = environment
+                .get_template(&template)
+                .map_err(LuaError::external)
+                .unwrap();
+
+            Ok(template
+                .render(context! {
+                  use_xml_format => context.use_xml_format,
+                  ask => context.ask,
+                  question => context.question,
+                  code_lang => context.code_lang,
+                  file_content => context.file_content,
+                  selected_code => context.selected_code,
+                  project_context => context.project_context,
+                  memory_context => context.memory_context,
+                })
+                .map_err(LuaError::external)
+                .unwrap())
+        }
+        None => Err(LuaError::RuntimeError(
+            "Environment not initialized".to_string(),
+        )),
+    }
+}
+
+fn initialize(state: &State, directory: String) {
+    let mut environment_mutex = state.environment.lock().unwrap();
+    // add directory as a base path for base directory template path
+    let mut env = Environment::new();
+    env.set_loader(path_loader(directory));
+    *environment_mutex = Some(env);
+}
+
+#[mlua::lua_module]
+fn avante_templates(lua: &Lua) -> LuaResult<LuaTable> {
+    let core = State::new();
+    let state = Arc::new(core);
+    let state_clone = Arc::clone(&state);
+
+    let exports = lua.create_table()?;
+    exports.set(
+        "initialize",
+        lua.create_function(move |_, model: String| {
+            initialize(&state, model);
+            Ok(())
+        })?,
+    )?;
+    exports.set(
+        "render",
+        lua.create_function_mut(move |lua, (template, context): (String, LuaValue)| {
+            let ctx = lua.from_value(context)?;
+            render(&state_clone, template, ctx)
+        })?,
+    )?;
+    Ok(exports)
+}