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fluxer_api/src/unfurler/resolvers/HackerNewsResolver.ts

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+/*
+ * Copyright (C) 2026 Fluxer Contributors
+ *
+ * This file is part of Fluxer.
+ *
+ * Fluxer is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Fluxer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import type {MessageEmbedResponse} from '~/channel/ChannelModel';
+import {Logger} from '~/Logger';
+import {BaseResolver} from '~/unfurler/resolvers/BaseResolver';
+import {htmlToMarkdown} from '~/utils/DOMUtils';
+import * as FetchUtils from '~/utils/FetchUtils';
+import {parseString} from '~/utils/StringUtils';
+
+interface HnItem {
+	id: number;
+	type: 'story' | 'comment' | 'job' | 'poll' | 'pollopt';
+	by?: string;
+	time: number;
+	text?: string;
+	dead?: boolean;
+	deleted?: boolean;
+	url?: string;
+	title?: string;
+	score?: number;
+	descendants?: number;
+	kids?: Array<number>;
+	parent?: number;
+	parts?: Array<number>;
+	poll?: number;
+}
+
+export class HackerNewsResolver extends BaseResolver {
+	private readonly API_BASE = 'https://hacker-news.firebaseio.com/v0';
+	private readonly SITE_BASE = 'https://news.ycombinator.com';
+	private readonly HN_COLOR = 0xff6600;
+	private readonly HN_ICON = 'https://fluxerstatic.com/embeds/icons/hn.webp';
+	private readonly MAX_DESCRIPTION_LENGTH = 400;
+
+	match(url: URL, mimeType: string, _content: Uint8Array): boolean {
+		return (
+			url.hostname === 'news.ycombinator.com' && url.pathname.startsWith('/item') && mimeType.startsWith('text/html')
+		);
+	}
+
+	async resolve(url: URL, _content: Uint8Array, _isNSFWAllowed: boolean = false): Promise<Array<MessageEmbedResponse>> {
+		try {
+			const itemId = new URLSearchParams(url.search).get('id');
+			if (!itemId) return [];
+
+			const item = await this.fetchItem(itemId);
+			if (!item) return [];
+
+			if (item.deleted || item.dead) {
+				Logger.debug({itemId}, 'Skipping deleted or dead HN item');
+				return [];
+			}
+
+			const embed = this.buildEmbed(item);
+			return [embed];
+		} catch (error) {
+			Logger.error({error, url: url.toString()}, 'Failed to resolve Hacker News item');
+			return [];
+		}
+	}
+
+	private async fetchItem(itemId: string): Promise<HnItem | null> {
+		try {
+			const response = await FetchUtils.sendRequest({
+				url: `${this.API_BASE}/item/${itemId}.json`,
+				timeout: 5000,
+			});
+
+			if (response.status !== 200) {
+				Logger.debug({itemId, status: response.status}, 'Failed to fetch HN item');
+				return null;
+			}
+
+			const responseText = await FetchUtils.streamToString(response.stream);
+			return JSON.parse(responseText) as HnItem;
+		} catch (error) {
+			Logger.error({error, itemId}, 'Failed to fetch or parse HN item');
+			return null;
+		}
+	}
+
+	private buildEmbed(item: HnItem): MessageEmbedResponse {
+		const embed: MessageEmbedResponse = {
+			type: 'rich',
+			url: this.getItemUrl(item.id),
+			color: this.HN_COLOR,
+			timestamp: this.formatTimestamp(item.time),
+			footer: {
+				text: 'Hacker News',
+				icon_url: this.HN_ICON,
+			},
+		};
+
+		if (this.hasTitle(item) && item.title) {
+			embed.title = parseString(item.title, 256);
+		}
+
+		if (item.by) {
+			embed.author = {
+				name: parseString(item.by, 256),
+			};
+		}
+
+		const description = this.buildDescription(item);
+		if (description) {
+			embed.description = description;
+		}
+
+		return embed;
+	}
+
+	private buildDescription(item: HnItem): string | undefined {
+		if (!item.text) return undefined;
+
+		const markdown = htmlToMarkdown(item.text);
+		const singleLine = markdown.replace(/\s+/g, ' ').trim();
+		if (!singleLine) return undefined;
+
+		return parseString(singleLine, this.MAX_DESCRIPTION_LENGTH);
+	}
+
+	private formatTimestamp(unixSeconds: number): string {
+		return new Date(unixSeconds * 1000).toISOString();
+	}
+
+	private hasTitle(item: HnItem): boolean {
+		return item.type === 'story' || item.type === 'job' || item.type === 'poll';
+	}
+
+	private getItemUrl(id: number): string {
+		return `${this.SITE_BASE}/item?id=${id}`;
+	}
+}