import { z } from "zod";
import type { RegisterFn } from "../types.js";
import { jsonResponse, jsonError, rateLimit, isZodError, zodError } from "../../util/json_response.js";
import { requireWriteAccess } from "../../util/access.js";
export const registerUpdateTopic: RegisterFn = (server, ctx, opts) => {
if (!opts?.allowWrites) return;
const schema = z.object({
topic_id: z.number().int().positive().describe("Topic ID to update"),
title: z.string().min(1).max(300).optional().describe("New title"),
category_id: z.number().int().positive().optional().describe("Move to category"),
tags: z.array(z.string().min(1).max(100)).max(10).optional().describe("Replace all tags"),
featured_link: z.string().url().optional().describe("Featured link URL"),
original_title: z.string().optional().describe("For conflict detection - expected current title"),
original_tags: z.array(z.string()).optional().describe("For conflict detection - expected current tags"),
});
server.registerTool(
"discourse_update_topic",
{
title: "Update Topic",
description: "Update an existing topic (title, category, tags, featured_link). Returns JSON with updated topic details.",
inputSchema: schema.shape,
},
async (args, _extra) => {
try {
const { topic_id, title, category_id, tags, featured_link, original_title, original_tags } = schema.parse(args);
const accessError = requireWriteAccess(ctx.siteState, opts.allowWrites);
if (accessError) return accessError;
// Fail fast if no updatable fields provided
if (title === undefined && category_id === undefined && tags === undefined && featured_link === undefined) {
return jsonError("At least one of title, category_id, tags, or featured_link is required");
}
await rateLimit("topic");
const { client } = ctx.siteState.ensureSelectedSite();
// Fetch current topic state for conflict detection
if (original_title !== undefined || original_tags !== undefined) {
const currentTopic = (await client.get(`/t/${encodeURIComponent(String(topic_id))}.json`)) as any;
if (original_title !== undefined && currentTopic?.title !== original_title) {
return jsonError("Conflict: topic was modified since last read", {
hint: "Re-read the topic to get current state before updating",
expected_title: original_title,
actual_title: currentTopic?.title,
});
}
if (original_tags !== undefined) {
const currentTags = Array.isArray(currentTopic?.tags) ? currentTopic.tags.sort() : [];
const expectedTags = [...original_tags].sort();
if (JSON.stringify(currentTags) !== JSON.stringify(expectedTags)) {
return jsonError("Conflict: topic was modified since last read", {
hint: "Re-read the topic to get current state before updating",
expected_tags: original_tags,
actual_tags: currentTopic?.tags || [],
});
}
}
}
// Build update payload - only include fields that were provided
const payload: Record<string, any> = {};
const updatedFields: string[] = [];
if (title !== undefined) {
payload.title = title;
updatedFields.push("title");
}
if (category_id !== undefined) {
payload.category_id = category_id;
updatedFields.push("category_id");
}
if (tags !== undefined) {
payload.tags = tags;
updatedFields.push("tags");
}
if (featured_link !== undefined) {
payload.featured_link = featured_link;
updatedFields.push("featured_link");
}
const data = (await client.put(
`/t/-/${encodeURIComponent(String(topic_id))}.json`,
payload
)) as any;
const topic = data?.basic_topic || data;
return jsonResponse({
success: true,
topic_id,
updated_fields: updatedFields,
topic: {
id: topic.id ?? topic_id,
title: topic.title ?? title,
slug: topic.slug ?? null,
category_id: topic.category_id ?? category_id ?? null,
tags: Array.isArray(topic.tags) ? topic.tags : (tags ?? []),
featured_link: topic.featured_link ?? featured_link ?? null,
},
});
} catch (e: unknown) {
if (isZodError(e)) return zodError(e);
const err = e as any;
const status = err?.status || err?.response?.status;
const body = err?.body || err?.response?.body;
if (status === 403) {
return jsonError("Permission denied: cannot update this topic", { status });
}
if (status === 409) {
return jsonError("Conflict: topic was modified since last read", {
hint: "Re-read the topic to get current state before updating",
status,
});
}
if (status === 422) {
const errors = body?.errors || err?.message;
return jsonError(`Validation failed: ${Array.isArray(errors) ? errors.join(", ") : errors}`, {
status,
body,
});
}
const details: Record<string, unknown> = {};
if (status) details.status = status;
if (body) details.body = body;
return jsonError(`Failed to update topic: ${err?.message || String(e)}`, Object.keys(details).length > 0 ? details : undefined);
}
}
);
};
