feat: can get actual available roots

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/hyperlog-server/src/querier.rs

@@ -1,17 +1,32 @@
 use hyperlog_core::log::GraphItem;
 
-use crate::state::SharedState;
+use crate::{
+    services::get_available_roots::{self, GetAvailableRoots, GetAvailableRootsExt},
+    state::SharedState,
+};
 
-pub struct Querier {}
+pub struct Querier {
+    get_available_roots: GetAvailableRoots,
+}
 
-#[allow(dead_code, unused_variables)]
 impl Querier {
-    pub fn new() -> Self {
-        Self {}
+    pub fn new(get_available_roots: GetAvailableRoots) -> Self {
+        Self {
+            get_available_roots,
+        }
     }
 
-    pub fn get_available_roots(&self) -> Option<Vec<String>> {
-        todo!()
+    pub async fn get_available_roots(&self) -> anyhow::Result<Option<Vec<String>>> {
+        let res = self
+            .get_available_roots
+            .execute(get_available_roots::Request {})
+            .await?;
+
+        if res.roots.is_empty() {
+            return Ok(None);
+        }
+
+        Ok(Some(res.roots))
     }
 
     pub fn get(
@@ -29,6 +44,6 @@ pub trait QuerierExt {
 
 impl QuerierExt for SharedState {
     fn querier(&self) -> Querier {
-        Querier::new()
+        Querier::new(self.get_available_roots_service())
     }
 }