// comment_on_approve — docs TRIGGER on `comments` (update). When a comment
// transitions INTO "approved", publish it to the public `comments-feed` topic
// so post pages can show it live over SSE. (Comments are public once approved.)
let ev = ctx.event.docs;
if ev == () { return; }
let data = ev.data;
if data == () { return; }

let was = if ev.prev_data == () { () } else { ev.prev_data.status };
let became_approved = data.status == "approved" && was != "approved";
if !became_approved { return; }

pubsub::publish_durable("comments-feed", #{
    post_id: data.post_id,
    post_slug: data.post_slug,
    author_name: data.author_name,   // already HTML-escaped at write time
    body: data.body,                 // already HTML-escaped at write time
    created_at: data.created_at,
});
log::info("published approved comment", #{ post: data.post_id });