feat: implement friends API with routes to get friends list and update thought visibility logic

thoughts-backend/app/src/persistence/thought.rs

@@ -45,8 +45,36 @@ pub async fn create_thought(
     Ok(new_thought)
 }
 
-pub async fn get_thought(db: &DbConn, thought_id: Uuid) -> Result<Option<thought::Model>, DbErr> {
-    thought::Entity::find_by_id(thought_id).one(db).await
+pub async fn get_thought(
+    db: &DbConn,
+    thought_id: Uuid,
+    viewer_id: Option<Uuid>,
+) -> Result<Option<thought::Model>, DbErr> {
+    let thought = thought::Entity::find_by_id(thought_id).one(db).await?;
+
+    match thought {
+        Some(t) => {
+            if t.visibility == thought::Visibility::Public {
+                return Ok(Some(t));
+            }
+
+            if let Some(viewer) = viewer_id {
+                if t.author_id == viewer {
+                    return Ok(Some(t));
+                }
+
+                if t.visibility == thought::Visibility::FriendsOnly {
+                    let author_friends = follow::get_friend_ids(db, t.author_id).await?;
+                    if author_friends.contains(&viewer) {
+                        return Ok(Some(t));
+                    }
+                }
+            }
+
+            Ok(None)
+        }
+        None => Ok(None),
+    }
 }
 
 pub async fn delete_thought(db: &DbConn, thought_id: Uuid) -> Result<(), DbErr> {

thoughts-backend/app/src/persistence/user.rs

@@ -9,7 +9,7 @@ use models::params::user::{CreateUserParams, UpdateUserParams};
 use models::queries::user::UserQuery;
 
 use crate::error::UserError;
-use crate::persistence::follow::{get_follower_ids, get_following_ids};
+use crate::persistence::follow::{get_follower_ids, get_following_ids, get_friend_ids};
 
 pub async fn create_user(
     db: &DbConn,
@@ -142,6 +142,14 @@ pub async fn get_top_friends(db: &DbConn, user_id: Uuid) -> Result<Vec<user::Mod
         .await
 }
 
+pub async fn get_friends(db: &DbConn, user_id: Uuid) -> Result<Vec<user::Model>, DbErr> {
+    let friend_ids = get_friend_ids(db, user_id).await?;
+    if friend_ids.is_empty() {
+        return Ok(vec![]);
+    }
+    get_users_by_ids(db, friend_ids).await
+}
+
 pub async fn get_following(db: &DbConn, user_id: Uuid) -> Result<Vec<user::Model>, DbErr> {
     let following_ids = get_following_ids(db, user_id).await?;
     if following_ids.is_empty() {