From 3ee97b5d4315f018715a71961305c9d4caba854b Mon Sep 17 00:00:00 2001
From: Alex Selimov <alex@alexselimov.com>
Date: Mon, 15 Jun 2026 13:21:50 -0400
Subject: [PATCH] Add route for getting most popular posts

---
 src/env.rs            |  3 +-
 src/main.rs           |  6 ++--
 src/votes/handlers.rs | 80 +++++++++++++++++++++++++++++++++++++++++--
 src/votes/model.rs    |  3 +-
 4 files changed, 84 insertions(+), 8 deletions(-)

diff --git a/src/env.rs b/src/env.rs
index 5b44f38..273e07f 100644
--- a/src/env.rs
+++ b/src/env.rs
@@ -18,8 +18,7 @@ impl Env {
             .map(|s| s.trim().to_string())
             .collect();
 
-        let port = env::var("PORT")
-            .unwrap_or_else(|_| "3000".to_string());
+        let port = env::var("PORT").unwrap_or_else(|_| "3000".to_string());
 
         Env {
             postgres_connection_string,
diff --git a/src/main.rs b/src/main.rs
index f7280c3..91cb63b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -14,9 +14,9 @@ async fn main() {
 
     let state = AppState::new().await;
     let port = &state.env.port;
-    let listener = tokio::net::TcpListener::bind(format!("0.0.0.0:{port}")).await.unwrap();
-    tracing::info!("listening on {}", listener.local_addr().unwrap());
-    axum::serve(listener, upvoters::app(state))
+    let listener = tokio::net::TcpListener::bind(format!("0.0.0.0:{port}"))
         .await
         .unwrap();
+    tracing::info!("listening on {}", listener.local_addr().unwrap());
+    axum::serve(listener, upvoters::app(state)).await.unwrap();
 }
diff --git a/src/votes/handlers.rs b/src/votes/handlers.rs
index ced29a9..21c15ed 100644
--- a/src/votes/handlers.rs
+++ b/src/votes/handlers.rs
@@ -1,18 +1,19 @@
 use axum::{
     Json, Router,
-    extract::{Path, State},
+    extract::{Path, Query, State},
     http::StatusCode,
     response::IntoResponse,
     routing::{delete, get, post},
 };
 use axum_extra::extract::{CookieJar, cookie::Cookie};
+use serde::{Deserialize, Serialize};
 use tracing::{error, info};
 use uuid::Uuid;
 
 use crate::{
     state::AppState,
     votes::{
-        repository::{delete_vote, insert_new_vote},
+        repository::{delete_vote, get_top_n_slugs, insert_new_vote},
         service::get_votes_and_voted,
     },
 };
@@ -22,6 +23,7 @@ pub fn router() -> Router<AppState> {
         .route("/posts/{slug}/vote", post(upvote_handler))
         .route("/posts/{slug}/vote", delete(delete_vote_handler))
         .route("/posts/{slug}/votes", get(get_votes_and_voted_handler))
+        .route("/posts/best", get(get_best_handler))
 }
 
 fn get_or_init_voter_id(jar: CookieJar) -> (CookieJar, Uuid) {
@@ -110,6 +112,30 @@ async fn get_votes_and_voted_handler(
     }
 }
 
+#[derive(Serialize, Deserialize)]
+struct BestVotesQuery {
+    top: usize,
+}
+
+async fn get_best_handler(
+    jar: CookieJar,
+    State(state): State<AppState>,
+    query: Query<BestVotesQuery>,
+) -> impl IntoResponse {
+    match get_top_n_slugs(query.top as i64, &state.db).await {
+        Ok(top_slugs) => {
+            info!(n=%query.top, "fetched most popular slugs successfully");
+            (StatusCode::OK, jar, Json(top_slugs)).into_response()
+        }
+        Err(err) => {
+            error!(
+                error = %err,
+                "failed to fetch popular slugs"
+            );
+            (StatusCode::INTERNAL_SERVER_ERROR, jar, "Failed to upvote").into_response()
+        }
+    }
+}
 #[cfg(test)]
 mod tests {
     use axum::{
@@ -333,4 +359,54 @@ mod tests {
 
         delete_votes_for_slug(slug, &db).await.unwrap();
     }
+
+    #[tokio::test]
+    async fn get_best_returns_top_slugs_limited_by_query() {
+        let db = test_pool().await;
+        let slugs = [
+            "get_best_handler_top_post_1",
+            "get_best_handler_top_post_2",
+            "get_best_handler_top_post_3",
+        ];
+
+        for slug in slugs {
+            delete_votes_for_slug(slug, &db).await.unwrap();
+        }
+
+        for voter_id in [
+            Uuid::from_u128(0x100),
+            Uuid::from_u128(0x101),
+            Uuid::from_u128(0x102),
+        ] {
+            insert_new_vote(slugs[0], &voter_id, &db).await.unwrap();
+        }
+        for voter_id in [Uuid::from_u128(0x200), Uuid::from_u128(0x201)] {
+            insert_new_vote(slugs[1], &voter_id, &db).await.unwrap();
+        }
+        insert_new_vote(slugs[2], &Uuid::from_u128(0x300), &db)
+            .await
+            .unwrap();
+
+        let app = crate::app(test_state(db.clone()));
+        let request = Request::builder()
+            .method("GET")
+            .uri("/posts/best?top=2")
+            .body(Body::empty())
+            .unwrap();
+
+        let response = app.oneshot(request).await.unwrap();
+
+        assert_eq!(response.status(), StatusCode::OK);
+        let body = to_bytes(response.into_body(), usize::MAX).await.unwrap();
+        let json: Value = serde_json::from_slice(&body).unwrap();
+        assert_eq!(json.as_array().unwrap().len(), 2);
+        assert_eq!(json[0]["slug"], slugs[0]);
+        assert_eq!(json[0]["vote_count"], 3);
+        assert_eq!(json[1]["slug"], slugs[1]);
+        assert_eq!(json[1]["vote_count"], 2);
+
+        for slug in slugs {
+            delete_votes_for_slug(slug, &db).await.unwrap();
+        }
+    }
 }
diff --git a/src/votes/model.rs b/src/votes/model.rs
index df5e2e0..4993c5d 100644
--- a/src/votes/model.rs
+++ b/src/votes/model.rs
@@ -1,4 +1,5 @@
 use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
 use sqlx::prelude::FromRow;
 use uuid::Uuid;
 
@@ -11,7 +12,7 @@ pub struct Vote {
 }
 
 /// Struct representing the best slug posts
-#[derive(Debug, FromRow)]
+#[derive(Debug, FromRow, Serialize, Deserialize)]
 pub struct BestSlugs {
     pub slug: String,
     pub vote_count: i64,