Keep number of direct replies in reply_count field

migrations/V0004__post__add_reply_count.sql

@@ -0,0 +1 @@
+ALTER TABLE post ADD COLUMN reply_count INTEGER NOT NULL CHECK (reply_count >= 0) DEFAULT 0;

migrations/schema.sql

@@ -34,6 +34,7 @@ CREATE TABLE post (
     author_id UUID NOT NULL REFERENCES actor_profile (id) ON DELETE CASCADE,
     content TEXT NOT NULL,
     in_reply_to_id UUID REFERENCES post (id) ON DELETE CASCADE,
+    reply_count INTEGER NOT NULL CHECK (reply_count >= 0) DEFAULT 0,
     ipfs_cid VARCHAR(200),
     token_id INTEGER,
     token_tx_id VARCHAR(200),

src/mastodon_api/statuses/types.rs

@@ -14,6 +14,7 @@ pub struct Status {
     pub account: Account,
     pub content: String,
     pub in_reply_to_id: Option<Uuid>,
+    pub replies_count: i32,
     pub media_attachments: Vec<Attachment>,
 
     // Extra fields
@@ -34,6 +35,7 @@ impl Status {
             account: account,
             content: post.content,
             in_reply_to_id: post.in_reply_to_id,
+            replies_count: post.reply_count,
             media_attachments: attachments,
             ipfs_cid: post.ipfs_cid,
             token_id: post.token_id,

src/models/posts/queries.rs

@@ -96,6 +96,8 @@ pub async fn create_post(
             &created_at,
         ],
     ).await?;
+    let db_post: DbPost = post_row.try_get("post")?;
+    // Create links to attachments
     let attachment_rows = transaction.query(
         "
         UPDATE media_attachment
@@ -110,14 +112,19 @@ pub async fn create_post(
             row.try_get("media_attachment")
         })
         .collect::<Result<_, _>>()?;
-    let db_post: DbPost = post_row.try_get("post")?;
+    // Update counters
     let author = update_post_count(&transaction, &db_post.author_id, 1).await?;
+    if let Some(in_reply_to_id) = &db_post.in_reply_to_id {
+        update_reply_count(&transaction, in_reply_to_id, 1).await?;
+    }
+
     transaction.commit().await?;
     let post = Post {
         id: db_post.id,
         author: author,
         content: db_post.content,
         in_reply_to_id: db_post.in_reply_to_id,
+        reply_count: db_post.reply_count,
         attachments: db_attachments,
         ipfs_cid: db_post.ipfs_cid,
         token_id: db_post.token_id,
@@ -247,6 +254,26 @@ pub async fn update_post(
     Ok(())
 }
 
+pub async fn update_reply_count(
+    db_client: &impl GenericClient,
+    post_id: &Uuid,
+    change: i32,
+) -> Result<(), DatabaseError> {
+    let updated_count = db_client.execute(
+        "
+        UPDATE post
+        SET reply_count = reply_count + $1
+        WHERE id = $2
+        RETURNING post
+        ",
+        &[&change, &post_id],
+    ).await?;
+    if updated_count == 0 {
+        return Err(DatabaseError::NotFound("post"));
+    }
+    Ok(())
+}
+
 pub async fn is_waiting_for_token(
     db_client: &impl GenericClient,
 ) -> Result<bool, DatabaseError> {

src/models/posts/types.rs

@@ -17,6 +17,7 @@ pub struct DbPost {
     pub author_id: Uuid,
     pub content: String,
     pub in_reply_to_id: Option<Uuid>,
+    pub reply_count: i32,
     pub ipfs_cid: Option<String>,
     pub token_id: Option<i32>,
     pub token_tx_id: Option<String>,
@@ -29,6 +30,7 @@ pub struct Post {
     pub author: DbActorProfile,
     pub content: String,
     pub in_reply_to_id: Option<Uuid>,
+    pub reply_count: i32,
     pub attachments: Vec<DbMediaAttachment>,
     pub ipfs_cid: Option<String>,
     pub token_id: Option<i32>,
@@ -49,6 +51,7 @@ impl TryFrom<&Row> for Post {
             author: db_profile,
             content: db_post.content,
             in_reply_to_id: db_post.in_reply_to_id,
+            reply_count: db_post.reply_count,
             attachments: db_attachments,
             ipfs_cid: db_post.ipfs_cid,
             token_id: db_post.token_id,