phase-10.5: screener enhancements

server/domains/digest/DigestService.ts

@@ -0,0 +1,110 @@
+import { SignalSnapshotRepository } from '../shared/persistence/SignalSnapshotRepository';
+import { NewsRepository } from '../news/NewsRepository';
+import { SIGNAL_ORDER } from '../shared/config/constants';
+import type {
+  DigestCatalyst,
+  DigestChange,
+  DigestReport,
+  NewsArticleRow,
+  SignalSnapshotRow,
+} from '../shared/types';
+
+/**
+ * Daily change digest (PRODUCT.md P1.1) — the step that makes the snapshot
+ * ledger and the news pipeline actionable together.
+ *
+ * For each ticker snapshotted today, diff against its most recent previous
+ * snapshot. A signal flip alone is just information; a signal flip WITH a
+ * known catalyst attached is the highest-value alert the free stack can
+ * produce. M&A stories are always surfaced, change or no change.
+ *
+ * Run order matters: screen first (writes today's snapshots), digest second.
+ */
+export class DigestService {
+  /** How many days back to look for catalyst stories per ticker. */
+  private static readonly NEWS_LOOKBACK_DAYS = 2;
+
+  constructor(
+    private readonly snapshots: SignalSnapshotRepository,
+    private readonly news: NewsRepository,
+  ) {}
+
+  build(date = new Date().toISOString().slice(0, 10)): DigestReport {
+    const today = this.snapshots.byDate(date);
+    const previous = new Map(this.snapshots.latestBefore(date).map((r) => [r.ticker, r]));
+
+    const newsSince = DigestService.daysBefore(date, DigestService.NEWS_LOOKBACK_DAYS);
+    const changes: DigestChange[] = [];
+    const newTickers: string[] = [];
+    const maStories = new Map<string, DigestCatalyst>(); // url → story, deduped
+
+    for (const snap of today) {
+      const prev = previous.get(snap.ticker);
+      const catalysts = this.news
+        .newsForTicker(snap.ticker, newsSince)
+        .map(DigestService.toCatalyst);
+
+      // Always collect M&A stories, even without a signal change
+      for (const c of catalysts) {
+        if (c.catalyst === 'ma') maStories.set(c.url, c);
+      }
+
+      if (!prev) {
+        newTickers.push(snap.ticker);
+        continue;
+      }
+      if (prev.signal === snap.signal) continue;
+
+      changes.push({
+        ticker: snap.ticker,
+        previousSignal: prev.signal,
+        newSignal: snap.signal,
+        previousDate: prev.snapshot_date,
+        scoreDelta: DigestService.scoreDelta(prev, snap),
+        price: snap.price,
+        catalysts,
+      });
+    }
+
+    // Strongest impact first: biggest move across the signal ordering
+    changes.sort((a, b) => DigestService.impact(b) - DigestService.impact(a));
+
+    return {
+      date,
+      changes,
+      newTickers,
+      maStories: [...maStories.values()],
+      snapshotCount: today.length,
+    };
+  }
+
+  // ── Helpers ───────────────────────────────────────────────────────────────
+
+  private static toCatalyst(row: NewsArticleRow): DigestCatalyst {
+    return {
+      headline: row.headline,
+      catalyst: row.catalyst,
+      source: row.source,
+      url: row.url,
+      publishedAt: row.published_at,
+    };
+  }
+
+  private static scoreDelta(prev: SignalSnapshotRow, curr: SignalSnapshotRow): number | null {
+    if (prev.fundamental_score == null || curr.fundamental_score == null) return null;
+    return +(curr.fundamental_score - prev.fundamental_score).toFixed(1);
+  }
+
+  /** Distance moved across the signal ordering (Strong Buy=0 … Avoid=4). */
+  private static impact(change: DigestChange): number {
+    const ord = (s: string) => SIGNAL_ORDER[s] ?? 5;
+    return Math.abs(ord(change.newSignal) - ord(change.previousSignal));
+  }
+
+  /** YYYY-MM-DD `n` days before the given day. */
+  private static daysBefore(date: string, n: number): string {
+    const d = new Date(`${date}T00:00:00.000Z`);
+    d.setUTCDate(d.getUTCDate() - n);
+    return d.toISOString().slice(0, 10);
+  }
+}