phase-6: typescript introduction

server/analyst/CatalystAnalyst.ts

@@ -0,0 +1,72 @@
+import { YahooClient } from '../market/YahooClient.js';
+import type { Logger } from '../types.js';
+
+interface Story {
+  title: string;
+  publisher: string;
+  link: string;
+  relatedTickers: string[];
+}
+
+interface CatalystResult {
+  tickers: string[];
+  stories: Story[];
+}
+
+const NEWS_QUERIES = ['stock market today', 'earnings report', 'market news'];
+const MAX_STORIES = 15;
+const TICKER_REGEX = /^[A-Z]{1,6}$/;
+
+export class CatalystAnalyst {
+  private client: YahooClient;
+  private logger: Pick<Logger, 'write'>;
+
+  constructor({ logger }: { logger?: Pick<Logger, 'write'> } = {}) {
+    this.client = new YahooClient();
+    this.logger = logger ?? { write: (msg: string) => process.stdout.write(msg) };
+  }
+
+  async run(): Promise<CatalystResult> {
+    this.logger.write('🔍 Fetching market news...');
+    const stories = await this._fetchNews();
+    const tickers = this._extractTickers(stories);
+    this.logger.write(` ${stories.length} stories, ${tickers.length} tickers\n`);
+    return { tickers, stories };
+  }
+
+  private async _fetchNews(): Promise<Story[]> {
+    const seen = new Map<string, Story>();
+    for (const query of NEWS_QUERIES) {
+      try {
+        const { news = [] } = await (this.client as any).yf.search(query, {
+          newsCount: 8,
+          quotesCount: 0,
+        });
+        for (const s of news as any[]) {
+          if (!seen.has(s.title)) {
+            seen.set(s.title, {
+              title: s.title,
+              publisher: s.publisher,
+              link: s.link,
+              relatedTickers: s.relatedTickers ?? [],
+            });
+          }
+        }
+      } catch {
+        /* skip failed query */
+      }
+    }
+    return [...seen.values()].slice(0, MAX_STORIES);
+  }
+
+  private _extractTickers(stories: Story[]): string[] {
+    const tickers = new Set<string>();
+    for (const { relatedTickers } of stories) {
+      for (const t of relatedTickers) {
+        const clean = t.split(':')[0].toUpperCase();
+        if (TICKER_REGEX.test(clean)) tickers.add(clean);
+      }
+    }
+    return [...tickers];
+  }
+}