import { z } from "zod";
import type { RegisterFn } from "../types.js";
import { jsonResponse, jsonError } from "../../util/json_response.js";
export const registerReadTopic: RegisterFn = (server, ctx) => {
const schema = z.object({
topic_id: z.number().int().positive(),
post_limit: z.number().int().min(1).max(50).optional().describe("Max posts to return (default 5, max 50)"),
start_post_number: z.number().int().min(1).optional().describe("Start from this post number (1-based)")
});
server.registerTool(
"discourse_read_topic",
{
title: "Read Topic",
description: "Read topic metadata and posts. Returns JSON with id, title, slug, category_id, tags, and posts array.",
inputSchema: schema.shape,
},
async ({ topic_id, post_limit = 5, start_post_number }, _extra) => {
try {
const { client } = ctx.siteState.ensureSelectedSite();
const start = start_post_number ?? 1;
let current = start;
const fetchedPosts: Array<{
id: number;
post_number: number;
username: string;
created_at: string;
raw: string;
}> = [];
let topicData: any = null;
const maxBatches = 10;
const limit = Number.isFinite(ctx.maxReadLength) ? ctx.maxReadLength : 50000;
for (let i = 0; i < maxBatches && fetchedPosts.length < post_limit; i++) {
const url = current > 1
? `/t/${topic_id}.json?post_number=${current}&include_raw=true`
: `/t/${topic_id}.json?include_raw=true`;
const data = (await client.get(url)) as any;
if (i === 0) {
topicData = data;
}
const stream: any[] = Array.isArray(data?.post_stream?.posts) ? data.post_stream.posts : [];
const sorted = stream.slice().sort((a, b) => (a.post_number || 0) - (b.post_number || 0));
const filtered = sorted.filter((p) => (p.post_number || 0) >= current);
for (const p of filtered) {
if (fetchedPosts.length >= post_limit) break;
fetchedPosts.push({
id: p.id,
post_number: p.post_number,
username: p.username,
created_at: p.created_at,
raw: (p.raw || p.cooked || p.excerpt || "").toString().slice(0, limit),
});
}
if (filtered.length === 0) break;
current = (filtered[filtered.length - 1]?.post_number || current) + 1;
}
return jsonResponse({
id: topic_id,
title: topicData?.title || `Topic ${topic_id}`,
slug: topicData?.slug || String(topic_id),
category_id: topicData?.category_id || null,
tags: Array.isArray(topicData?.tags) ? topicData.tags : [],
posts_count: topicData?.posts_count || fetchedPosts.length,
posts: fetchedPosts,
meta: {
start_post: start,
returned: fetchedPosts.length,
has_more: (topicData?.posts_count || 0) > (start + fetchedPosts.length - 1),
},
});
} catch (e: any) {
return jsonError(`Failed to read topic ${topic_id}: ${e?.message || String(e)}`);
}
}
);
};
